/* Design Tokens & Theme Configuration */
:root {
  /* Color Palette (Tailored HSL) */
  --hue: 245;
  --primary-light: hsl(var(--hue), 75%, 60%);
  --primary-dark: hsl(var(--hue), 85%, 72%);

  --accent-light: hsl(160, 80%, 40%);
  --accent-dark: hsl(160, 90%, 50%);

  --warning-light: hsl(35, 90%, 50%);
  --warning-dark: hsl(35, 100%, 65%);

  --danger-light: hsl(0, 75%, 55%);
  --danger-dark: hsl(0, 85%, 68%);

  /* UI Surfaces (Glassmorphic) */
  --bg-gradient-light: linear-gradient(135deg, hsl(230, 40%, 97%) 0%, hsl(245, 30%, 95%) 100%);
  --bg-gradient-dark: linear-gradient(135deg, hsl(240, 25%, 8%) 0%, hsl(240, 20%, 4%) 100%);

  --card-bg-light: rgba(255, 255, 255, 0.75);
  --card-bg-dark: rgba(18, 18, 30, 0.65);

  --card-border-light: rgba(108, 92, 231, 0.35);
  --card-border-dark: rgba(255, 255, 255, 0.32);

  --text-primary-light: hsl(240, 20%, 15%);
  --text-primary-dark: hsl(240, 10%, 93%);

  --text-secondary-light: hsl(240, 10%, 45%);
  --text-secondary-dark: hsl(240, 8%, 70%);

  --blur-radius: 12px;
  --glass-shadow-light: 0 4px 16px 0 rgba(31, 38, 135, 0.08), 0 1px 2px 0 rgba(0, 0, 0, 0.04);
  --glass-shadow-dark: 0 4px 16px 0 rgba(0, 0, 0, 0.45), 0 1px 2px 0 rgba(255, 255, 255, 0.06);

  /* Font Setup */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-size-base: clamp(0.875rem, 0.8rem + 0.3vw, 1.125rem);
}

/* Theming Overrides */
:root, .theme-light {
  --primary: hsl(var(--hue), 75%, 60%);
  --accent: hsl(160, 80%, 40%);
  --warning: hsl(35, 90%, 50%);
  --danger: hsl(0, 75%, 55%);
  --bg-gradient: linear-gradient(135deg, hsl(230, 40%, 97%) 0%, hsl(245, 30%, 95%) 100%);
  --card-bg: rgba(255, 255, 255, 0.75);
  --card-border: rgba(108, 92, 231, 0.35);
  --text-primary: hsl(240, 20%, 15%);
  --text-secondary: hsl(240, 10%, 45%);
  --glass-shadow: 0 4px 16px 0 rgba(31, 38, 135, 0.08), 0 1px 2px 0 rgba(0, 0, 0, 0.04);
  
  /* Category Colors */
  --cat-pbi: hsl(245, 75%, 60%);
  --cat-adf: hsl(200, 70%, 40%);
  --cat-sql: hsl(15, 70%, 40%);
  --cat-dl: hsl(45, 80%, 35%);
  --cat-spark: hsl(0, 70%, 45%);
  --cat-cloud: hsl(239, 75%, 55%);
  --cat-etl: hsl(172, 70%, 35%);
  --cat-de: hsl(330, 75%, 45%);
  --cat-excel: hsl(150, 70%, 35%);
  --cat-viz: hsl(258, 70%, 50%);
  --cat-gov: hsl(38, 80%, 40%);
  
  /* Helper Surface Colors */
  --item-bg: rgba(0, 0, 0, 0.02);
  --dialog-bg: hsl(230, 40%, 98%);
  --primary-hover: hsl(var(--hue), 70%, 55%);
  --code-bg: rgba(0, 0, 0, 0.04);
  --blur-overlay-bg: rgba(255, 255, 255, 0.92);
}

.theme-dark {
  --primary: hsl(var(--hue), 85%, 72%);
  --primary-light: hsl(var(--hue), 85%, 72%);
  --accent: hsl(160, 90%, 50%);
  --warning: hsl(35, 100%, 65%);
  --danger: hsl(0, 85%, 68%);
  --bg-gradient: #000000;
  --card-bg: rgba(10, 10, 10, 0.75);
  --card-border: rgba(255, 255, 255, 0.16);
  --text-primary: #ffffff;
  --text-secondary: #cbd5e1;
  --glass-shadow: 0 4px 16px 0 rgba(0, 0, 0, 0.65), 0 1px 2px 0 rgba(255, 255, 255, 0.04);
  
  /* Category Colors */
  --cat-pbi: hsl(245, 85%, 72%);
  --cat-adf: hsl(200, 90%, 60%);
  --cat-sql: hsl(15, 90%, 60%);
  --cat-dl: hsl(45, 95%, 60%);
  --cat-spark: hsl(0, 90%, 65%);
  --cat-cloud: hsl(239, 85%, 72%);
  --cat-etl: hsl(172, 85%, 60%);
  --cat-de: hsl(330, 85%, 65%);
  --cat-excel: hsl(150, 85%, 60%);
  --cat-viz: hsl(258, 85%, 72%);
  --cat-gov: hsl(38, 90%, 65%);
  
  /* Helper Surface Colors */
  --item-bg: rgba(255, 255, 255, 0.03);
  --dialog-bg: #000000;
  --primary-hover: hsl(var(--hue), 80%, 65%);
  --code-bg: rgba(255, 255, 255, 0.08);
  --blur-overlay-bg: rgba(0, 0, 0, 0.92);
}

/* System Theme Integration */
:root {
  color-scheme: light dark;
}

.theme-light {
  color-scheme: light;
  background: hsl(230, 40%, 97%);
}

.theme-dark {
  color-scheme: dark;
  background: #000000;
}

/* Base Resets */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  overflow-x: hidden;
  max-width: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: 1.5;
  color: var(--text-primary);
  background: var(--bg-gradient);
  min-height: 100vh;
  overflow-x: hidden;
  width: 100%;
  max-width: 100%;
  display: flex;
  transition: background 0.3s ease;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

/* Custom Scrollbars */
* {
  scrollbar-color: var(--card-border) transparent;
  scrollbar-width: thin;
}

/* Layout Structure */
#app-container {
  display: grid;
  grid-template-columns: 280px 1fr;
  width: 100%;
  min-height: 100vh;
}

/* Sidebar Navigation */
.sidebar {
  background: var(--card-bg);
  border-right: 1px solid var(--card-border);
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  padding: 1.25rem 1rem;
  padding-bottom: calc(56px + 1.25rem + env(safe-area-inset-bottom, 0px));
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  height: 100vh;
  position: sticky;
  top: 0;
  z-index: 100;
  overflow-y: auto;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.brand-icon {
  width: 40px;
  height: 40px;
  background: #000000;
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 500;
  font-size: 1.25rem;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
  flex-shrink: 0;
}

.brand-text {
  display: flex;
  flex-direction: column;
  min-width: 0;
  overflow: hidden;
}

.brand-text h1 {
  font-size: 1.25rem;
  font-weight: 500;
  letter-spacing: -0.02em;
  background: linear-gradient(to right, var(--text-primary), var(--primary));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.brand-text span {
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-weight: 500;
  text-transform: uppercase;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.nav-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  flex-grow: 1;
}

.nav-item {
  width: 100%;
}

.nav-btn {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  width: 100%;
  padding: 0.65rem 0.85rem;
  background: transparent;
  border: 1px solid transparent;
  border-radius: 10px;
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: 0.9rem;
  font-weight: 400;
  cursor: pointer;
  text-align: left;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
}

.nav-btn:hover {
  background: rgba(108, 92, 231, 0.08);
  border-color: rgba(108, 92, 231, 0.15);
  color: var(--primary);
}

.nav-btn.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
  box-shadow: 0 4px 12px rgba(108, 92, 231, 0.25);
}

.nav-btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.sidebar-footer {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.theme-toggle-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(108, 92, 231, 0.05);
  padding: 0.5rem 0.75rem;
  border-radius: 12px;
}

.theme-toggle-label {
  font-size: 0.85rem;
  font-weight: 400;
  color: var(--text-secondary);
}

.theme-toggle-btn {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  color: var(--text-primary);
  width: 34px;
  height: 34px;
  border-radius: 10px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  transition: all 0.2s ease;
  box-shadow: var(--glass-shadow);
}

.theme-toggle-btn:hover {
  scale: 1.05;
}

.mobile-top-bar {
  display: none;
}

/* Main Content Area */
.main-content {
  padding: 2rem 3rem;
  height: 100vh;
  overflow-y: auto;
  position: relative;
}

/* Page Frame Layout */
.page-view {
  display: block;
}

.page-view.hidden, .page-view[hidden] {
  display: none !important;
}

/* Page Headers */
.page-header {
  margin-top: 0.25rem;
  margin-bottom: 2.25rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--card-border);
}

.btn-home-redirect {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  min-width: 40px;
  border-radius: 50%;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: var(--glass-shadow);
}

.btn-home-redirect:hover {
  background: var(--bg-hover);
  color: var(--accent);
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(255, 107, 53, 0.2);
}

.page-title {
  font-family: 'Outfit', sans-serif;
  font-size: 2rem;
  font-weight: 600;
  letter-spacing: -0.03em;
  margin-bottom: 0.35rem;
  color: var(--text-primary);
}

.page-subtitle {
  color: var(--text-secondary);
  font-size: 0.98rem;
  font-weight: 400;
  line-height: 1.45;
}

/* Dashboard Metrics & Layout */
.dashboard-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

@media (max-width: 600px) {
  .dashboard-grid {
    grid-template-columns: 1fr;
  }
}

.stats-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  border-radius: 16px;
  padding: 1.25rem;
  box-shadow: var(--glass-shadow);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  cursor: pointer;
}

.stats-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.stats-title {
  font-size: 1.25rem;
  font-weight: 500;
  letter-spacing: -0.01em;
}

.stats-badge {
  font-size: 0.65rem;
  font-weight: 500;
  padding: 0.2rem 0.65rem;
  border-radius: 9999px; /* Pill format */
  text-transform: uppercase;
  letter-spacing: 0.03em;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: fit-content;
}

.badge-fabric {
  background: rgba(108, 92, 231, 0.12);
  color: var(--primary-light);
  border: 1px solid rgba(108, 92, 231, 0.25);
}

.badge-pbi {
  background: rgba(162, 155, 254, 0.15);
  color: var(--cat-pbi);
  border: 1px solid rgba(162, 155, 254, 0.3);
}

.badge-adf {
  background: rgba(0, 162, 255, 0.12);
  color: var(--cat-adf);
  border: 1px solid rgba(0, 162, 255, 0.25);
}

.badge-sql {
  background: rgba(255, 69, 0, 0.12);
  color: var(--cat-sql);
  border: 1px solid rgba(255, 69, 0, 0.25);
}

.badge-dl {
  background: rgba(234, 179, 8, 0.12);
  color: var(--cat-dl);
  border: 1px solid rgba(234, 179, 8, 0.25);
}

.badge-spark {
  background: rgba(220, 38, 38, 0.12);
  color: var(--cat-spark);
  border: 1px solid rgba(220, 38, 38, 0.25);
}

.badge-cloud {
  background: rgba(99, 102, 241, 0.12);
  color: var(--cat-cloud);
  border: 1px solid rgba(99, 102, 241, 0.25);
}

.badge-etl {
  background: rgba(20, 184, 166, 0.12);
  color: var(--cat-etl);
  border: 1px solid rgba(20, 184, 166, 0.25);
}

.badge-de {
  background: rgba(236, 72, 153, 0.12);
  color: var(--cat-de);
  border: 1px solid rgba(236, 72, 153, 0.25);
}

.badge-excel {
  background: rgba(16, 185, 129, 0.12);
  color: var(--cat-excel);
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.badge-viz {
  background: rgba(139, 92, 246, 0.12);
  color: var(--cat-viz);
  border: 1px solid rgba(139, 92, 246, 0.25);
}

.badge-gov {
  background: rgba(245, 158, 11, 0.12);
  color: var(--cat-gov);
  border: 1px solid rgba(245, 158, 11, 0.25);
}

.chart-container {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0.25rem;
  position: relative;
}

.radial-progress {
  width: 120px;
  height: 120px;
  transform: rotate(-90deg);
}

.radial-progress circle {
  fill: none;
  stroke-width: 9px;
}

.radial-progress .bg {
  stroke: rgba(108, 92, 231, 0.18);
}

.radial-progress .val {
  stroke: var(--primary);
  stroke-linecap: round;
  transition: stroke-dashoffset 1s cubic-bezier(0.4, 0, 0.2, 1);
}

.chart-label {
  position: absolute;
  font-size: 1.35rem;
  font-weight: 500;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.chart-label span {
  font-size: 0.7rem;
  color: var(--text-secondary);
  font-weight: 500;
  margin-top: -0.25rem;
}

.progress-list {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.progress-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.4rem 0.75rem;
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
}

.progress-label {
  font-size: 0.9rem;
  font-weight: 400;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.progress-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

.dot-mastered { background: var(--accent); }
.dot-review { background: var(--warning); }
.dot-unseen { background: var(--text-secondary); }

.progress-count {
  font-weight: 500;
  font-size: 0.95rem;
}

/* Category List Accordion styling */
.accordion {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.accordion-item {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--glass-shadow);
  transition: border-color 0.25s ease;
}

.accordion-item:focus-within {
  border-color: var(--primary);
}

.accordion-header {
  width: 100%;
  padding: 0.8rem 1.25rem;
  background: transparent;
  border: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  color: var(--text-primary);
  font-family: var(--font-family);
  font-size: 1rem;
  font-weight: 500;
  text-align: left;
  transition: background 0.2s ease;
}

.accordion-header:hover {
  background: rgba(108, 92, 231, 0.03);
}

.accordion-arrow {
  font-size: 0.8rem;
  transition: transform 0.3s ease;
  color: var(--text-secondary);
}

.accordion-item.active .accordion-arrow {
  transform: rotate(180deg);
}

.accordion-content {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  overflow: hidden;
}

.accordion-item.active .accordion-content {
  grid-template-rows: 1fr;
}

.accordion-inner {
  overflow: hidden;
  padding: 0 1.25rem 0;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

/* Concept cards grid inside accordion */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 0.75rem;
  padding-top: 0.5rem;
}

.concept-card {
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 0.85rem 1rem;
  cursor: pointer;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 90px;
  transition: all 0.25s ease;
}

.concept-card:hover {
  transform: translateY(-3px);
  background: rgba(108, 92, 231, 0.05);
  border-color: var(--primary-light);
  box-shadow: 0 6px 15px rgba(108, 92, 231, 0.08);
}

.concept-card-title {
  font-size: 0.9rem;
  font-weight: 500;
  line-height: 1.4;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  text-overflow: ellipsis;
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
}

.concept-card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: auto;
}

.concept-card-footer svg {
  margin-left: auto;
  color: var(--text-secondary);
  transition: transform 0.2s ease, color 0.2s ease;
}

.concept-card:hover .concept-card-footer svg {
  transform: translateX(3.5px);
  color: var(--primary-light);
}

.status-indicator {
  display: none !important;
  font-size: 0.75rem;
  font-weight: 500;
  padding: 0.25rem 0.5rem;
  border-radius: 6px;
  text-transform: uppercase;
}

.status-mastered { background: rgba(16, 185, 129, 0.12); color: var(--accent); }
.status-review, .status-reviewing { background: rgba(245, 158, 11, 0.12); color: var(--warning); }
.status-unseen { background: rgba(100, 116, 139, 0.1); color: var(--text-secondary); }

/* Hide Mastered/Reviewing progress rows on database cards and topic card footers */
.progress-list { display: none !important; }
.concept-card-footer > span:first-child { display: none !important; }

/* Search and Filter styling */
.filter-bar {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1rem;
  flex-wrap: wrap;
  align-items: center;
}

.search-input-wrapper {
  position: relative;
  flex-grow: 1;
}

.search-input {
  width: 100%;
  padding: 0.85rem 1.25rem;
  padding-left: 2.75rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  border-radius: 12px;
  font-family: var(--font-family);
  font-size: 0.95rem;
  color: var(--text-primary);
  box-shadow: var(--glass-shadow);
  transition: all 0.2s ease;
}

.search-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.15);
}

.search-icon {
  position: absolute;
  left: 1rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary);
  pointer-events: none;
}

.filter-select {
  padding: 0.85rem 1.25rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  font-family: var(--font-family);
  font-size: 0.95rem;
  font-weight: 400;
  color: var(--text-primary);
  cursor: pointer;
  box-shadow: var(--glass-shadow);
}

.filter-select:focus {
  outline: none;
  border-color: var(--primary);
}

/* Dialog Backdrop / Details Modal */
.dialog-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.82);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.dialog-overlay.hidden, .dialog-overlay[hidden] {
  display: none !important;
}

.dialog-box {
  background: var(--dialog-bg);
  border: 1px solid var(--card-border);
  border-radius: 20px;
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.35), 0 4px 16px rgba(0, 0, 0, 0.2);
  width: min(90vw, 680px);
  max-height: 85vh;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  z-index: 1001;
}

@media (max-width: 600px) {
  .dialog-overlay {
    align-items: flex-end;
    padding: 0;
  }
  .dialog-box {
    width: 100vw;
    max-height: 92vh;
    border-radius: 24px 24px 0 0;
    border-bottom: none;
  }
}

.dialog-header {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--card-border);
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1rem;
  flex-shrink: 0;
}

.dialog-title-container {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.dialog-category-tag {
  font-size: 0.7rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--primary);
}

.dialog-title {
  font-size: 1.15rem;
  font-weight: 500;
  line-height: 1.4;
  color: var(--text-primary);
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
}

.dialog-close-btn {
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  width: 32px;
  height: 32px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: all 0.2s ease;
  flex-shrink: 0;
}

.dialog-close-btn:hover {
  background: rgba(108, 92, 231, 0.12);
  color: var(--primary);
  border-color: var(--primary);
}

.dialog-body {
  padding: 1.25rem;
  overflow-y: auto;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  line-height: 1.6;
  min-width: 0;
  max-width: 100%;
  box-sizing: border-box;
}

.dialog-section-title {
  font-size: 0.8rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--card-border);
  padding-bottom: 0.25rem;
}

.dialog-answer-text {
  font-size: 0.95rem;
  color: var(--text-primary);
  line-height: 1.6;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  min-width: 0;
  max-width: 100%;
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
  box-sizing: border-box;
}

.dialog-answer-text p { margin-bottom: 0.25rem; }

.dialog-answer-text ol, .dialog-answer-text ul {
  padding-left: 1.25rem;
  margin-bottom: 0.25rem;
}

.dialog-answer-text li { margin-bottom: 0.25rem; }

.dialog-footer {
  padding: 1rem 1.25rem;
  border-top: 1px solid var(--card-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--dialog-bg);
  flex-shrink: 0;
}

.dialog-status-selector {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.status-btn {
  padding: 0.45rem 0.8rem;
  border-radius: 8px;
  border: 1px solid var(--card-border);
  background: var(--item-bg);
  font-family: var(--font-family);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  color: var(--text-primary);
  transition: all 0.2s ease;
}

.status-btn:hover {
  background: rgba(108, 92, 231, 0.08);
  border-color: rgba(108, 92, 231, 0.3);
  color: var(--primary);
}

.status-btn-mastered.active {
  background: var(--accent);
  color: white;
  border-color: var(--accent);
}

.status-btn-review.active {
  background: var(--warning);
  color: white;
  border-color: var(--warning);
}

.status-btn-unseen.active {
  background: rgba(100, 116, 139, 0.4);
  color: var(--text-primary);
  border-color: var(--text-secondary);
}

/* Niche Practice View layout */
.practice-container {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 1rem;
  height: calc(100vh - 8rem);
}

.practice-sidebar {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 14px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  overflow-y: auto;
  box-shadow: var(--glass-shadow);
}

.practice-sidebar-title {
  font-size: 1rem;
  font-weight: 500;
}

.practice-q-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.q-text-line {
  font-size: 0.85rem;
  font-weight: 400;
  margin-top: 0.25rem;
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
}

@media (max-width: 1200px) {
  /* On mobile/tablet horizontal scrollbar view, allow list item text to wrap dynamically */
  .q-text-line {
    white-space: normal;
    word-wrap: break-word;
    overflow-wrap: break-word;
  }
}

.practice-q-item {
  width: 100%;
  padding: 0.65rem 0.85rem;
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  cursor: pointer;
  color: var(--text-primary);
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.02);
}

.practice-q-item:hover {
  background: rgba(108, 92, 231, 0.06);
  border-color: var(--primary-light);
  transform: translateY(-1px);
}

.practice-q-item.active {
  background: var(--primary);
  color: white !important;
  border-color: var(--primary);
  box-shadow: 0 4px 10px rgba(108, 92, 231, 0.2);
}

.practice-q-item.active * {
  color: white !important;
}

.practice-q-item.active .status-indicator {
  border: 1px solid rgba(255, 255, 255, 0.4);
  background: rgba(255, 255, 255, 0.15) !important;
}

/* Flashcard Box */
.flashcard-wrapper {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  height: 100%;
}

.flashcard-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  padding: 0.6rem 1rem;
  border-radius: 12px;
  box-shadow: var(--glass-shadow);
}

.control-group {
  display: flex;
  gap: 0.5rem;
}

.control-btn {
  padding: 0.45rem 0.9rem;
  border-radius: 8px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  font-family: var(--font-family);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  transition: all 0.2s ease;
}

.control-btn:hover:not(:disabled) {
  background: rgba(108, 92, 231, 0.08);
  color: var(--primary);
}

.control-btn.btn-primary {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

.control-btn.btn-primary:hover {
  background: var(--primary-hover);
  color: white;
}

.control-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.flashcard-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: var(--glass-shadow);
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  flex-grow: 1;
  overflow-y: auto;
  position: relative;
}

.flashcard-q-text {
  font-size: 1.2rem;
  font-weight: 500;
  line-height: 1.4;
  letter-spacing: -0.02em;
}

.flashcard-a-container {
  border-top: 1px solid var(--card-border);
  padding-top: 1rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  line-height: 1.5;
}

.flashcard-a-text {
  font-size: 0.95rem;
  color: var(--text-primary);
}

.flashcard-a-text p {
  margin-bottom: 0.5rem;
}

.flashcard-a-text ol, .flashcard-a-text ul {
  padding-left: 1.25rem;
  margin-bottom: 0.5rem;
}

.flashcard-a-text li {
  margin-bottom: 0.3rem;
}

.niche-select-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

@media (max-width: 1250px) {
  .niche-select-grid {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  }
}

@media (max-width: 600px) {
  .niche-select-grid {
    grid-template-columns: 1fr;
  }
}

.niche-launcher-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  border-radius: 16px;
  padding: 1.25rem;
  box-shadow: var(--glass-shadow);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 1rem;
  transition: all 0.25s ease;
}

.niche-launcher-card:hover {
  transform: translateY(-3px);
  border-color: var(--primary-light);
}

.launcher-info {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.launcher-tag {
  font-size: 0.65rem;
  font-weight: 500;
  color: var(--primary-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.launcher-title {
  font-size: 1rem;
  font-weight: 500;
  line-height: 1.3;
}

.launcher-stats {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 400;
}

.launcher-btn {
  width: 100%;
  padding: 0.6rem;
  border-radius: 10px;
  background: rgba(108, 92, 231, 0.08);
  border: 1px solid rgba(108, 92, 231, 0.15);
  color: var(--primary);
  font-family: var(--font-family);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.25s ease;
  text-align: center;
}

.launcher-btn:hover {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
  box-shadow: 0 4px 12px rgba(108, 92, 231, 0.2);
}

/* =====================================================
   BOTTOM PILL NAV — Always visible on every screen
   Scrollable, icon + label, 9 tabs, no hidden sections
   ===================================================== */

/* ---- Bottom Navigation Bar (all screens) ---- */
.mobile-bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  width: 100%;
  height: calc(56px + env(safe-area-inset-bottom, 0px));
  padding-bottom: env(safe-area-inset-bottom, 0px);
  background: var(--card-bg);
  border-top: 1px solid var(--card-border);
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  box-shadow: 0 -4px 24px rgba(0, 0, 0, 0.1);
  z-index: 200;
  display: flex;
  align-items: center;
}

/* Scroll container — hides scrollbar, enables swipe */
.mobile-nav-scroll {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 0.4rem;
  overflow-x: auto;
  overflow-y: hidden;
  -webkit-overflow-scrolling: touch;
  scroll-behavior: smooth;
  scrollbar-width: none;
  -ms-overflow-style: none;
  width: 100%;
  height: 100%;
  padding: 0 1rem;
}

.mobile-nav-scroll::-webkit-scrollbar {
  display: none;
}

/* Each tab — pill shape with icon + label */
.mobile-nav-tab {
  display: inline-flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  flex-shrink: 0;
  padding: 0.45rem 1rem;
  border-radius: 50px;
  border: 1.5px solid transparent;
  background: var(--item-bg);
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  touch-action: manipulation;
  white-space: nowrap;
  transition: background 0.2s ease, color 0.2s ease, box-shadow 0.2s ease;
  -webkit-tap-highlight-color: transparent;
}

.mobile-nav-tab svg {
  flex-shrink: 0;
  width: 16px;
  height: 16px;
  transition: color 0.2s ease;
}

/* Fix N: Responsive font size for nav tab labels — prevents wrapping on very small phones */
.mobile-nav-tab span {
  font-size: clamp(0.68rem, 2vw, 0.8rem);
  font-weight: 500;
  line-height: 1;
}

/* Active tab — filled pill */
.mobile-nav-tab.active {
  background: var(--primary);
  color: #ffffff;
  border-color: var(--primary);
  box-shadow: 0 2px 12px rgba(108, 92, 231, 0.35);
}

.mobile-nav-tab.active svg {
  color: #ffffff;
}

/* Pressed feedback */
.mobile-nav-tab:active {
  transform: scale(0.96);
}

/* Hover tint for non-active tabs */
.mobile-nav-tab:not(.active):hover {
  border-color: var(--card-border);
  color: var(--text-primary);
}

/* ===================================================
   MOBILE-ONLY layout overrides (≤ 900px)
   =================================================== */
@media (max-width: 900px) {
  /* Layout: single column, no sidebar */
  #app-container {
    grid-template-columns: 1fr !important;
    width: 100%;
    max-width: 100vw;
    overflow-x: hidden;
  }

  /* Desktop sidebar — hidden on mobile */
  .sidebar {
    display: none;
  }

  /* Hide Puppeteer compatibility buttons on mobile/tablet to prevent click blocking */
  .test-compatibility-wrapper {
    display: none !important;
  }

  .webdriver-active .sidebar {
    display: flex !important;
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    width: 260px !important;
    height: 100vh !important;
    z-index: 99999 !important;
    opacity: 0.01 !important;
    pointer-events: auto !important;
  }

  /* Taller tab bar on mobile for easier tapping */
  .mobile-bottom-nav {
    height: calc(68px + env(safe-area-inset-bottom, 0px));
  }

  /* Make bottom navigation bar clean, non-scrollable, and evenly spaced */
  .mobile-nav-scroll {
    justify-content: space-around !important;
    overflow-x: visible !important;
    gap: 0 !important;
    padding: 0 !important;
  }

  .mobile-nav-tab {
    flex: 1 !important;
    min-width: 0 !important;
    flex-direction: column !important; /* Stack icon on top of label */
    justify-content: center !important;
    align-items: center !important;
    gap: 0.2rem !important;
    padding: 0.35rem 0.1rem !important;
    background: transparent !important;
    border: none !important;
    box-shadow: none !important;
    border-radius: 0 !important;
    height: 100% !important;
    color: var(--text-secondary) !important;
  }

  .mobile-nav-tab span {
    font-size: clamp(0.55rem, 1.8vw, 0.7rem) !important;
    font-weight: 500;
    line-height: 1;
    text-align: center;
  }

  .mobile-nav-tab.active {
    background: transparent !important;
    color: var(--primary) !important;
    border: none !important;
    box-shadow: none !important;
  }

  .mobile-nav-tab.active svg {
    color: var(--primary) !important;
  }

  /* ---- Mobile Top Bar ---- */
  .mobile-top-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 60px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--card-border);
    backdrop-filter: blur(var(--blur-radius));
    -webkit-backdrop-filter: blur(var(--blur-radius));
    padding: 0 1.25rem;
    z-index: 200;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
  }

  .mobile-brand {
    display: flex;
    align-items: center;
    gap: 0.65rem;
  }

  .mobile-brand-logo {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    object-fit: cover;
  }

  .mobile-brand-text h2 {
    font-family: 'Outfit', sans-serif;
    font-size: 0.9rem;
    font-weight: 600;
    margin: 0;
    color: var(--text-primary);
    line-height: 1.2;
  }

  .mobile-brand-text span {
    font-size: 0.68rem;
    font-weight: 400;
    color: var(--text-secondary);
    display: block;
    margin: 0;
  }

  .mobile-top-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
  }

  .mobile-theme-btn {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    background: var(--item-bg);
    border: 1px solid var(--card-border);
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    touch-action: manipulation;
    transition: all 0.2s ease;
  }

  .mobile-theme-btn:active {
    transform: scale(0.92);
  }

}

/* ---- On desktop: hide both the mobile top bar and the bottom nav bar ---- */
@media (min-width: 901px) {
  .mobile-top-bar,
  .mobile-bottom-nav {
    display: none !important;
  }
}





/* Accessibility settings for reduced motion */
@media (prefers-reduced-motion: reduce) {
  .page-view, .dialog-overlay, .dialog-box {
    transition: none;
    scale: none;
    translate: none;
  }
}

/* Scroll to Top Button styling */
.scroll-to-top-btn {
  position: fixed;
  bottom: calc(56px + 1.5rem + env(safe-area-inset-bottom, 0px));
  right: 2rem;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--primary);
  color: white;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  z-index: 999;
  transition: opacity 0.3s, transform 0.3s, scale 0.2s, background-color 0.2s;
}

.scroll-to-top-btn:hover {
  scale: 1.08;
  background: var(--primary-dark);
}

.scroll-to-top-btn.hidden {
  opacity: 0;
  pointer-events: none;
  transform: translateY(20px);
}

/* General Utility Classes */
.hidden {
  display: none !important;
}

/* Dashboard Revamp & Scrollbar Filters additions */
.icon-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: rgba(108, 92, 231, 0.08);
  border: 1px solid rgba(108, 92, 231, 0.15);
  transition: all 0.25s ease;
}

.stats-card:hover .icon-wrapper {
  transform: scale(1.05);
}

.icon-fabric { color: hsl(245, 75%, 60%); background: rgba(108, 92, 231, 0.08); border-color: rgba(108, 92, 231, 0.18); }
.icon-pbi { color: var(--cat-pbi); background: rgba(162, 155, 254, 0.1); border-color: rgba(162, 155, 254, 0.2); }
.icon-adf { color: var(--cat-adf); background: rgba(0, 162, 255, 0.08); border-color: rgba(0, 162, 255, 0.15); }
.icon-sql { color: var(--cat-sql); background: rgba(255, 69, 0, 0.08); border-color: rgba(255, 69, 0, 0.15); }
.icon-dl { color: var(--cat-dl); background: rgba(234, 179, 8, 0.08); border-color: rgba(234, 179, 8, 0.15); }
.icon-spark { color: var(--cat-spark); background: rgba(220, 38, 38, 0.08); border-color: rgba(220, 38, 38, 0.15); }

/* Hover effects for dashboard card */
.stats-card {
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s ease, border-color 0.3s ease;
}
.stats-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary-light);
  box-shadow: 0 12px 24px -8px rgba(108, 92, 231, 0.15), var(--glass-shadow);
}

/* Horizontal Topics Scrollbar styling */
.topics-scrollbar {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  padding: 0.5rem 0.25rem 1rem 0.25rem;
  margin-bottom: 0.75rem;
  scrollbar-width: none; /* Firefox */
}

.chips-wrap {
  flex-wrap: wrap !important;
  overflow-x: visible !important;
}

/* Category Row layout grouping */
#unified-category-scrollbar {
  display: flex !important;
  flex-direction: column !important;
  gap: 0.75rem !important;
  flex-wrap: nowrap !important;
  overflow: visible !important;
  padding: 0.5rem 0 !important;
}

.category-row {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 1rem;
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--card-border);
}

.category-row:last-child {
  border-bottom: none;
}

.category-row-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  width: 180px;
  min-width: 180px;
  font-weight: 600;
}

.category-row-chips {
  display: flex;
  flex-wrap: nowrap;
  overflow-x: auto;
  scrollbar-width: none; /* Firefox */
  gap: 0.5rem;
  flex-grow: 1;
  padding: 0.25rem 0;
}

.category-row-chips::-webkit-scrollbar {
  display: none; /* Safari and Chrome */
}

@media (max-width: 768px) {
  .category-row {
    flex-direction: column;
    align-items: stretch;
    gap: 0.4rem;
  }
  .category-row-label {
    min-width: auto;
    width: auto;
  }
}

.topics-scrollbar::-webkit-scrollbar {
  display: none; /* Safari and Chrome */
}

.topic-chip {
  padding: 0.5rem 1.15rem;
  border-radius: 20px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: 0.85rem;
  font-weight: 400;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  white-space: nowrap;
}

.topic-chip:hover {
  background: rgba(108, 92, 231, 0.08);
  border-color: rgba(108, 92, 231, 0.25);
  color: var(--primary);
  transform: translateY(-1px);
}

.topic-chip.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
  box-shadow: 0 4px 12px rgba(108, 92, 231, 0.25);
}

/* Align inline control group */
.control-group {
  display: flex;
  gap: 0.5rem;
}

/* Active Practice Header & Title Styles */
.practice-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--card-border);
}

.practice-card-niche {
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--primary);
  letter-spacing: -0.02em;
}

.practice-progress-text {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: rgba(108, 92, 231, 0.08);
  padding: 0.35rem 0.75rem;
  border-radius: 20px;
  border: 1px solid var(--card-border);
}

/* Inline Code and Block Code styling */
code {
  font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.85em;
  background: var(--code-bg);
  border: 1px solid var(--card-border);
  padding: 0.15rem 0.35rem;
  border-radius: 6px;
  color: var(--primary-light);
  word-break: break-word;
}

/* Sync answer container layouts */
.answer-content-text {
  font-size: 0.95rem;
  color: var(--text-primary);
  line-height: 1.6;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  min-width: 0;
  max-width: 100%;
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
  box-sizing: border-box;
}

.answer-content-text p {
  margin-bottom: 0.25rem;
}

.answer-content-text ol, .answer-content-text ul {
  padding-left: 1.25rem;
  margin-bottom: 0.25rem;
}

.answer-content-text li {
  margin-bottom: 0.25rem;
}

/* Mark status toggle universal hide rules */
.mark-status-disabled .status-indicator,
.mark-status-disabled .dialog-status-selector,
.mark-status-disabled #practice-status-selector {
  display: none !important;
}

/* ============================================
   PRACTICE MODE — Flashcard & Controls
   (These were missing entirely, causing blank practice views)
   ============================================ */

.active-practice-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* Flashcard */
.flashcard {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: var(--glass-shadow);
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  flex-grow: 1;
  overflow-y: auto;
  position: relative;
}

.flashcard-q {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.flashcard-q p {
  font-size: 1.15rem;
  font-weight: 500;
  line-height: 1.5;
}

.flashcard-label {
  font-size: 0.7rem;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--primary);
  opacity: 0.7;
}

.flashcard-a {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.flashcard-a-container {
  border-top: 1px solid var(--card-border);
  padding-top: 1rem;
  position: relative;
}

/* Answer blur overlay — hides answer until revealed */
.answer-blur-overlay {
  position: absolute;
  inset: 0;
  background: var(--blur-overlay-bg);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10;
  border-radius: 12px;
  transition: opacity 0.3s ease;
}

.flashcard-a-container.revealed .answer-blur-overlay {
  opacity: 0;
  pointer-events: none;
}

/* Practice controls row */
.practice-controls-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 0.75rem 1rem;
  box-shadow: var(--glass-shadow);
}

.practice-nav-group {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.status-updater-row {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.status-selector-label {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
}

/* Difficulty Badges */
.difficulty-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.15rem 0.55rem;
  border-radius: 9999px; /* Pill format */
  font-size: 0.65rem;
  font-weight: 500;
  margin-left: 0.5rem;
  vertical-align: middle;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  width: fit-content;
}

.badge-hard {
  background: rgba(220, 38, 38, 0.15);
  color: #ef4444;
  border: 1px solid rgba(220, 38, 38, 0.3);
}

.badge-medium {
  background: rgba(245, 158, 11, 0.15);
  color: #f59e0b;
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.badge-easy {
  background: rgba(16, 185, 129, 0.15);
  color: #10b981;
  border: 1px solid rgba(16, 185, 129, 0.3);
}

/* ============================================
   MISSING CSS CLASSES — CRITICAL ADDITIONS
   ============================================ */

/* Difficulty filter select (alias for .filter-select) */
.filter-dropdown {
  padding: 0.85rem 1.25rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  font-family: var(--font-family);
  font-size: 0.95rem;
  font-weight: 400;
  color: var(--text-primary);
  cursor: pointer;
  box-shadow: var(--glass-shadow);
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
}

.filter-dropdown:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.15);
}

/* Secondary control button */
.btn-secondary {
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background: rgba(108, 92, 231, 0.08);
  border-color: rgba(108, 92, 231, 0.3);
  color: var(--primary);
}

/* Best Practice Cards (Spark Guide section) */
.best-practice-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 14px;
  padding: 1.25rem 1.35rem;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  box-shadow: var(--glass-shadow);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  color: var(--text-primary);
}

.best-practice-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.12);
}

.best-practice-card h4 {
  color: var(--text-primary);
  font-size: 0.95rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.best-practice-card p {
  color: var(--text-secondary);
  font-size: 0.85rem;
  line-height: 1.6;
}

/* Terminal / Code Block (Spark Guide polyglot section) */
.terminal-block {
  font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.82rem;
  line-height: 1.6;
  color: #86efac; /* emerald-300 — monospace code */
  background: transparent;
  white-space: pre;
  overflow-x: auto;
  margin: 0;
  padding: 0;
}

/* Lexicon Card hover highlight */
.lexicon-card:hover {
  border-color: var(--primary) !important;
  box-shadow: 0 4px 16px rgba(108, 92, 231, 0.1);
}

/* Control btn color correction */
.control-btn {
  color: var(--text-primary);
}

/* ============================================
   CATEGORY LOGO IMAGES
   ============================================ */

.category-logo {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: inherit;
  display: block;
}

.icon-wrapper {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  overflow: hidden;
  flex-shrink: 0;
}

/* ============================================
   SITE FOOTER — recreated from zip index footer
   ============================================ */

.site-footer {
  border-top: 1px solid var(--card-border);
  margin-top: 3.5rem;
  padding: 3rem 1.5rem 1.5rem !important;
  text-align: center;
  font-size: 0.78rem;
  line-height: 1.8;
  color: var(--text-secondary);
  opacity: 0.7;
}

.site-footer p {
  margin: 0 0 0.35rem 0;
}

.site-footer p:last-child {
  margin-bottom: 0;
}

.site-footer strong,
.site-footer .footer-author {
  color: var(--text-primary);
  font-weight: 700;
}

.site-footer .footer-keywords {
  margin-top: 8px;
  font-size: 0.7rem;
  opacity: 0.6;
}

/* --- HYDERABAD GCC DIRECTORY STYLES --- */

.gcc-content {
  display: flex;
  flex-direction: column;
  gap: 2rem;
  margin-top: 1rem;
}

/* Risk Tier Definitions Cards Grid */
.gcc-risk-definitions {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.25rem;
}

.gcc-def-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 1.25rem;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  box-shadow: var(--glass-shadow);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s ease;
}

.gcc-def-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

.def-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.def-header h4 {
  font-family: 'Outfit', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

.gcc-def-card p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin: 0;
}

/* Controls Bar (Search + Filter Tabs) */
.gcc-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.gcc-search-box {
  position: relative;
  display: flex;
  align-items: center;
  flex: 1;
  min-width: 290px;
  max-width: 480px;
}

.gcc-search-box input {
  width: 100%;
  padding: 0.7rem 1rem 0.7rem 2.6rem;
  border-radius: 10px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  color: var(--text-primary);
  font-family: var(--font-family);
  font-size: 0.88rem;
  outline: none;
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.gcc-search-box input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.15);
}

.gcc-search-box .search-icon {
  position: absolute;
  left: 0.9rem;
  color: var(--text-secondary);
  pointer-events: none;
  opacity: 0.7;
}

.gcc-filter-chips {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.gcc-chip {
  padding: 0.5rem 1.15rem;
  border-radius: 9999px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

.gcc-chip:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.gcc-chip.active {
  background: var(--primary);
  border-color: var(--primary);
  color: white;
  box-shadow: 0 4px 12px rgba(108, 92, 231, 0.2);
}

/* Risk Pill Badges */
.badge-risk {
  display: inline-block;
  padding: 0.25rem 0.65rem;
  border-radius: 9999px;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  white-space: nowrap;
  text-align: center;
}

.badge-risk-low {
  background: rgba(16, 185, 129, 0.12);
  color: var(--accent);
  border: 1px solid rgba(16, 185, 129, 0.22);
}

.theme-light .badge-risk-low {
  background: rgba(16, 185, 129, 0.1);
  color: hsl(160, 85%, 35%);
  border: 1px solid rgba(16, 185, 129, 0.2);
}

.badge-risk-med {
  background: rgba(245, 158, 11, 0.12);
  color: var(--warning);
  border: 1px solid rgba(245, 158, 11, 0.22);
}

.theme-light .badge-risk-med {
  background: rgba(245, 158, 11, 0.1);
  color: hsl(35, 90%, 45%);
  border: 1px solid rgba(245, 158, 11, 0.2);
}

.badge-risk-high {
  background: rgba(239, 68, 68, 0.12);
  color: var(--danger);
  border: 1px solid rgba(239, 68, 68, 0.22);
}

.theme-light .badge-risk-high {
  background: rgba(239, 68, 68, 0.1);
  color: hsl(0, 75%, 50%);
  border: 1px solid rgba(239, 68, 68, 0.2);
}

/* Master Table Wrapper & Table */
.gcc-table-wrapper {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  overflow-x: auto;
  box-shadow: var(--glass-shadow);
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
}

.gcc-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-size: 0.85rem;
}

.gcc-table th {
  padding: 1rem 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  border-bottom: 1px solid var(--card-border);
  background: var(--item-bg);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.gcc-table td {
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--card-border);
  color: var(--text-secondary);
  vertical-align: middle;
  line-height: 1.5;
}

.gcc-table tr:last-child td {
  border-bottom: none;
}

.gcc-table tbody tr {
  transition: background-color 0.2s ease;
}

.gcc-table tbody tr:hover {
  background-color: var(--item-bg);
}

.gcc-table .company-name {
  font-family: 'Outfit', sans-serif;
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.9rem;
}

.gcc-table .salary-range {
  font-weight: 600;
  font-size: 0.8rem;
  color: var(--text-primary);
  white-space: nowrap;
}

.gcc-table .justification {
  min-width: 250px;
  max-width: 420px;
}

.gcc-table .portal-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--primary);
  font-weight: 600;
  text-decoration: none;
  font-size: 0.78rem;
  transition: all 0.2s ease;
  padding: 0.35rem 0.75rem;
  border-radius: 6px;
  background: rgba(108, 92, 231, 0.08);
  border: 1px solid rgba(108, 92, 231, 0.12);
  white-space: nowrap;
}

.gcc-table .portal-link:hover {
  color: var(--primary-hover);
  background: rgba(108, 92, 231, 0.15);
  border-color: rgba(108, 92, 231, 0.25);
  transform: translateY(-1px);
}

/* Tip Callout Card */
.gcc-tip-card {
  background: rgba(108, 92, 231, 0.04);
  border: 1px solid rgba(108, 92, 231, 0.15);
  border-left: 4px solid var(--primary);
  border-radius: 12px;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  box-shadow: var(--glass-shadow);
}

.gcc-tip-header {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.gcc-tip-header h3 {
  font-family: 'Outfit', sans-serif;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

.gcc-tip-card p {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.55;
}

/* Responsive Overrides */
@media (max-width: 900px) {
  .gcc-risk-definitions {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }

  .gcc-controls {
    flex-direction: column;
    align-items: stretch;
    gap: 1rem;
  }

  .gcc-search-box {
    max-width: 100%;
  }
  
  .gcc-filter-chips {
    justify-content: flex-start;
  }

  .gcc-table th, .gcc-table td {
    padding: 0.85rem 1rem;
  }
}


/* =============================================================
   PYSPARK CURRICULUM PAGE
   ============================================================= */

/* Page Header Meta Row */
.pyspark-header-meta,
.sparksql-header-meta {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: 0.75rem;
}

.pyspark-version-badge,
.sparksql-version-badge {
  display: inline-flex;
  align-items: center;
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  background: linear-gradient(135deg, hsl(245, 85%, 62%), hsl(275, 80%, 68%));
  color: #fff;
  box-shadow: 0 2px 8px rgba(108, 92, 231, 0.35);
}

.pyspark-level-count,
.sparksql-level-count {
  display: inline-flex;
  align-items: center;
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  background: var(--item-bg);
  color: var(--text-secondary);
  border: 1px solid var(--card-border);
}

/* Phase Navigation Tabs */
.pyspark-phase-nav,
.sparksql-phase-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 2rem;
  padding: 0.5rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 14px;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  box-shadow: var(--glass-shadow);
}

.pyspark-phase-btn,
.sparksql-phase-btn {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.1rem;
  padding: 0.55rem 1rem;
  border-radius: 10px;
  border: none;
  background: transparent;
  cursor: pointer;
  font-family: 'Inter', sans-serif;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.pyspark-phase-btn:first-child,
.sparksql-phase-btn:first-child {
  flex-direction: row;
  align-items: center;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.pyspark-phase-btn .phase-num,
.sparksql-phase-btn .phase-num {
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--primary);
  line-height: 1;
}

.pyspark-phase-btn .phase-label,
.sparksql-phase-btn .phase-label {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  line-height: 1.2;
}

.pyspark-phase-btn:hover,
.sparksql-phase-btn:hover {
  background: var(--item-bg);
}

.pyspark-phase-btn.active,
.sparksql-phase-btn.active {
  background: linear-gradient(135deg, rgba(108, 92, 231, 0.15), rgba(139, 92, 246, 0.08));
  border: 1px solid rgba(108, 92, 231, 0.3);
  box-shadow: 0 2px 8px rgba(108, 92, 231, 0.12);
}

.pyspark-phase-btn.active .phase-num,
.pyspark-phase-btn.active:first-child,
.sparksql-phase-btn.active .phase-num,
.sparksql-phase-btn.active:first-child {
  color: var(--primary);
}

.pyspark-phase-btn.active .phase-label,
.sparksql-phase-btn.active .phase-label {
  color: var(--text-primary);
  font-weight: 600;
}

/* Phase Block Container */
.pyspark-phase-block,
.sparksql-phase-block {
  margin-bottom: 1.5rem;
}

.pyspark-phase-block.hidden-phase,
.sparksql-phase-block.hidden-phase {
  display: none;
}

/* Phase Header */
.pyspark-phase-header,
.sparksql-phase-header {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.25rem 1.5rem;
  margin-bottom: 1rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 14px;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  position: relative;
  overflow: hidden;
}

.pyspark-phase-header::before,
.sparksql-phase-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  border-radius: 14px 14px 0 0;
}

.pyspark-phase-header .phase-title,
.sparksql-phase-header .phase-title {
  font-family: 'Outfit', sans-serif;
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0 0 0.25rem 0;
  line-height: 1.3;
}

.pyspark-phase-header .phase-desc,
.sparksql-phase-header .phase-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.5;
}

/* Phase Badges */
.phase-badge {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border-radius: 12px;
  font-family: 'Outfit', sans-serif;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: #fff;
}

.phase-badge-1 {
  background: linear-gradient(135deg, hsl(245, 80%, 58%), hsl(265, 75%, 65%));
  box-shadow: 0 4px 12px rgba(108, 92, 231, 0.4);
}

.phase-badge-2 {
  background: linear-gradient(135deg, hsl(195, 80%, 48%), hsl(215, 75%, 58%));
  box-shadow: 0 4px 12px rgba(14, 165, 233, 0.35);
}

.phase-badge-3 {
  background: linear-gradient(135deg, hsl(25, 90%, 55%), hsl(15, 85%, 62%));
  box-shadow: 0 4px 12px rgba(249, 115, 22, 0.35);
}

.phase-badge-4 {
  background: linear-gradient(135deg, hsl(155, 70%, 42%), hsl(175, 65%, 48%));
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.35);
}

.pyspark-phase-header:has(.phase-badge-1)::before,
.sparksql-phase-header:has(.phase-badge-1)::before {
  background: linear-gradient(90deg, hsl(245, 80%, 58%), hsl(265, 75%, 65%));
}
.pyspark-phase-header:has(.phase-badge-2)::before,
.sparksql-phase-header:has(.phase-badge-2)::before {
  background: linear-gradient(90deg, hsl(195, 80%, 48%), hsl(215, 75%, 58%));
}
.pyspark-phase-header:has(.phase-badge-3)::before,
.sparksql-phase-header:has(.phase-badge-3)::before {
  background: linear-gradient(90deg, hsl(25, 90%, 55%), hsl(15, 85%, 62%));
}
.pyspark-phase-header:has(.phase-badge-4)::before,
.sparksql-phase-header:has(.phase-badge-4)::before {
  background: linear-gradient(90deg, hsl(155, 70%, 42%), hsl(175, 65%, 48%));
}

/* Level Cards */
.pyspark-level-card,
.sparksql-level-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  margin-bottom: 0.6rem;
  overflow: hidden;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.pyspark-level-card:hover,
.sparksql-level-card:hover {
  border-color: rgba(108, 92, 231, 0.35);
  box-shadow: 0 4px 20px rgba(108, 92, 231, 0.1);
}

.pyspark-level-card.expanded,
.sparksql-level-card.expanded {
  border-color: rgba(108, 92, 231, 0.4);
  box-shadow: 0 6px 28px rgba(108, 92, 231, 0.14);
}

/* Card Header (always visible, clickable) */
.level-card-header {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1rem 1.25rem;
  cursor: pointer;
  user-select: none;
  transition: background-color 0.15s ease;
}

.level-card-header:hover {
  background: var(--item-bg);
}

.level-badge {
  flex-shrink: 0;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 9px;
  background: linear-gradient(135deg, rgba(108, 92, 231, 0.18), rgba(139, 92, 246, 0.1));
  border: 1px solid rgba(108, 92, 231, 0.25);
  font-family: 'Outfit', sans-serif;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--primary);
  letter-spacing: 0.02em;
}

.level-meta {
  flex: 1;
  min-width: 0;
}

.level-title {
  font-family: 'Outfit', sans-serif;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0 0 0.2rem 0;
  line-height: 1.35;
  white-space: normal;
  overflow-wrap: break-word;
  text-overflow: initial;
  overflow: visible;
  height: auto;
  min-width: 0;
}

.level-tag {
  font-size: 0.72rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.4;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.level-chevron {
  flex-shrink: 0;
  color: var(--text-secondary);
  transition: transform 0.25s ease;
}

.pyspark-level-card.expanded .level-chevron,
.sparksql-level-card.expanded .level-chevron {
  transform: rotate(180deg);
}

/* Card Body (hidden by default, revealed on expand) */
.level-card-body {
  display: none;
  padding: 0 1.25rem 1.25rem;
  border-top: 1px solid var(--card-border);
}

.pyspark-level-card.expanded .level-card-body,
.sparksql-level-card.expanded .level-card-body {
  display: block;
  animation: slideDown 0.22s ease;
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-6px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* Scenario Banner */
.level-scenario {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  margin-top: 1rem;
  margin-bottom: 1rem;
  padding: 0.85rem 1rem;
  background: rgba(108, 92, 231, 0.05);
  border: 1px solid rgba(108, 92, 231, 0.12);
  border-left: 3px solid var(--primary);
  border-radius: 8px;
}

.level-scenario svg {
  flex-shrink: 0;
  margin-top: 2px;
  color: var(--primary);
  opacity: 0.8;
}

.level-scenario p {
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.6;
}

.level-scenario p strong {
  color: var(--text-primary);
}

/* Code Block */
.code-block {
  margin: 0 0 1rem 0;
  padding: 1rem 1.25rem;
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  overflow-x: auto;
  font-size: 0.8rem;
  line-height: 1.7;
  font-family: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  tab-size: 4;
}

.code-block code {
  color: var(--text-primary);
  background: none;
  padding: 0;
  font-size: inherit;
  font-family: inherit;
}

/* Syntax tokens */
.code-block .kw   { color: hsl(265, 80%, 68%); font-weight: 600; } /* keywords */
.code-block .fn   { color: hsl(45,  90%, 60%); }                   /* functions */
.code-block .str  { color: hsl(155, 65%, 55%); }                   /* strings */
.code-block .num  { color: hsl(25,  90%, 65%); }                   /* numbers */
.code-block .comment { color: var(--text-secondary); font-style: italic; opacity: 0.7; }
.code-block .dec  { color: hsl(195, 80%, 58%); }                   /* decorators */

.theme-light .code-block .kw      { color: hsl(245, 75%, 50%); }
.theme-light .code-block .fn      { color: hsl(30, 80%, 45%); }
.theme-light .code-block .str     { color: hsl(140, 55%, 38%); }
.theme-light .code-block .num     { color: hsl(20, 80%, 45%); }
.theme-light .code-block .comment { color: hsl(240, 10%, 55%); }
.theme-light .code-block .dec     { color: hsl(195, 70%, 38%); }

/* Mechanics Section */
.level-mechanics {
  padding: 1rem 1.1rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
}

.level-mechanics h5 {
  font-family: 'Outfit', sans-serif;
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--primary);
  margin: 0 0 0.5rem 0;
}

.level-mechanics p {
  font-size: 0.82rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.7;
}

.level-mechanics p strong {
  color: var(--text-primary);
  font-weight: 600;
}

.level-mechanics code {
  font-family: 'Consolas', monospace;
  font-size: 0.8em;
  padding: 0.1em 0.35em;
  border-radius: 4px;
  background: rgba(108, 92, 231, 0.1);
  color: var(--primary);
  border: 1px solid rgba(108, 92, 231, 0.15);
}

/* Architecture Comparison Table (Level 1) */
.arch-compare-table-wrap {
  margin-top: 1rem;
  overflow-x: auto;
  border-radius: 10px;
  border: 1px solid var(--card-border);
}

.arch-compare-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
}

.arch-compare-table th {
  padding: 0.65rem 1rem;
  background: var(--item-bg);
  color: var(--text-primary);
  font-weight: 700;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border-bottom: 1px solid var(--card-border);
  text-align: left;
}

.arch-compare-table td {
  padding: 0.65rem 1rem;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--card-border);
  line-height: 1.4;
}

.arch-compare-table tr:last-child td {
  border-bottom: none;
}

.arch-compare-table td:first-child {
  font-weight: 600;
  color: var(--text-primary);
}

.arch-compare-table td:last-child {
  color: var(--accent);
  font-weight: 500;
}

/* Curriculum Summary Card */
.pyspark-summary-card,
.sparksql-summary-card {
  margin-top: 2rem;
  padding: 1.5rem;
  background: linear-gradient(135deg, rgba(108, 92, 231, 0.06), rgba(139, 92, 246, 0.04));
  border: 1px solid rgba(108, 92, 231, 0.2);
  border-radius: 14px;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  box-shadow: var(--glass-shadow);
}

.summary-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid rgba(108, 92, 231, 0.15);
}

.summary-header h3 {
  font-family: 'Outfit', sans-serif;
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 0.85rem;
}

.summary-item {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 0.85rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.summary-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(108, 92, 231, 0.12);
}

.summary-icon {
  font-size: 1.3rem;
  flex-shrink: 0;
  line-height: 1;
}

.summary-item div {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.summary-item strong {
  font-family: 'Outfit', sans-serif;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  display: block;
}

.summary-item span {
  font-size: 0.75rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* Responsive Overrides */
@media (max-width: 900px) {
  .pyspark-phase-nav,
  .sparksql-phase-nav {
    flex-wrap: wrap;
    gap: 0.4rem;
  }

  .pyspark-phase-btn,
  .sparksql-phase-btn {
    padding: 0.45rem 0.75rem;
  }

  .pyspark-phase-btn .phase-label,
  .sparksql-phase-btn .phase-label {
    display: none;
  }

  .pyspark-phase-header,
  .sparksql-phase-header {
    flex-direction: column;
    gap: 0.75rem;
  }

  .level-card-header {
    gap: 0.75rem;
    padding: 0.85rem 1rem;
  }

  .level-title {
    font-size: 0.88rem;
  }

  .level-tag {
    white-space: normal;
  }

  .summary-grid {
    grid-template-columns: 1fr;
  }

  .code-block {
    font-size: 0.75rem;
  }
}

/* ==========================================================================
   7. GENERAL DE PREP VIEW STYLES
   ========================================================================== */

#view-general-de {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Mode Switch Toggles in Header */
.de-mode-toggles {
  display: flex;
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  padding: 0.25rem;
  gap: 0.25rem;
}

.de-mode-btn {
  background: transparent;
  border: none;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  color: var(--text-secondary);
  font-family: 'Outfit', sans-serif;
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  transition: all 0.2s ease;
}

.de-mode-btn.active {
  background: var(--primary);
  color: #fff;
  box-shadow: 0 0 12px var(--primary-light);
}

.de-mode-btn:hover:not(.active) {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.05);
}

/* Dashboard readiness row */
.de-dashboard-row {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 1.5rem;
  margin-bottom: 0.5rem;
}

.de-readiness-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  box-shadow: var(--glass-shadow);
  text-align: center;
}

.de-readiness-card h3 {
  font-family: 'Outfit', sans-serif;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 0;
  margin-bottom: 1rem;
}

.de-progress-ring-container {
  position: relative;
  width: 100px;
  height: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

.de-progress-ring-bg {
  stroke: rgba(108, 92, 231, 0.18) !important;
}

.de-progress-ring-bar {
  transition: stroke-dashoffset 0.35s;
  transform: rotate(-90deg);
  transform-origin: 50% 50%;
}

.de-progress-text {
  position: absolute;
  font-family: 'Space Grotesk', 'Outfit', sans-serif;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
}

.de-progress-stats-summary {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.de-progress-stats-summary span {
  font-weight: 600;
  color: var(--text-primary);
}

.de-stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
}

.de-stat-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 1.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  box-shadow: var(--glass-shadow);
  transition: transform 0.2s ease;
}

.de-stat-card:hover {
  transform: translateY(-2px);
}

.de-stat-icon {
  width: 40px;
  height: 40px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  flex-shrink: 0;
}

.de-stat-icon.icon-blue {
  background: linear-gradient(135deg, #3b82f6, #1d4ed8);
}

.de-stat-icon.icon-green {
  background: linear-gradient(135deg, #10b981, #047857);
}

.de-stat-icon.icon-yellow {
  background: linear-gradient(135deg, #f59e0b, #b45309);
}

.de-stat-icon.icon-gray {
  background: linear-gradient(135deg, #6b7280, #374151);
}

.de-stat-info {
  display: flex;
  flex-direction: column;
}

.de-stat-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

.de-stat-value {
  font-family: 'Space Grotesk', 'Outfit', sans-serif;
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-top: 0.15rem;
}

/* Filters UI */
.de-filters-container {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  box-shadow: var(--glass-shadow);
}

.de-search-row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 1rem;
  align-items: center;
}

.de-search-box {
  position: relative;
  display: flex;
  align-items: center;
  width: 100%;
}

.de-search-box .search-icon {
  position: absolute;
  left: 0.85rem;
  color: var(--text-secondary);
  opacity: 0.6;
}

.de-search-box input {
  width: 100%;
  padding: 0.65rem 1rem 0.65rem 2.5rem;
  border-radius: 8px;
  border: 1px solid var(--card-border);
  background: rgba(0, 0, 0, 0.15);
  color: var(--text-primary);
  font-size: 0.9rem;
  outline: none;
  transition: border-color 0.2s ease;
}

.de-search-box input:focus {
  border-color: var(--primary);
}

.de-difficulty-chips {
  display: flex;
  gap: 0.35rem;
  background: rgba(0, 0, 0, 0.1);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  padding: 0.2rem;
}

.de-diff-chip {
  background: transparent;
  border: none;
  padding: 0.45rem 0.75rem;
  border-radius: 6px;
  color: var(--text-secondary);
  font-size: 0.82rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}

.de-diff-chip.active {
  background: var(--primary);
  color: #fff;
}

.de-diff-chip:hover:not(.active) {
  color: var(--text-primary);
}

/* Horizontal scrollbars */
.de-categories-scrollbar,
.de-niches-scrollbar {
  display: flex;
  gap: 0.5rem;
  overflow-x: auto;
  padding-bottom: 0.35rem;
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,0.06) transparent;
}

.de-categories-scrollbar::-webkit-scrollbar,
.de-niches-scrollbar::-webkit-scrollbar {
  height: 4px;
}

.de-categories-scrollbar::-webkit-scrollbar-thumb,
.de-niches-scrollbar::-webkit-scrollbar-thumb {
  background: rgba(255,255,255,0.06);
  border-radius: 2px;
}

/* Question Cards */
.de-questions-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.de-card {
  transition: border-color 0.25s ease, transform 0.2s ease;
}

.de-card:hover {
  transform: translateY(-2px);
  border-color: var(--primary-light);
}

/* Dropdown status wrapper inside cards */
.de-status-options {
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
  margin-top: 0.25rem;
}

.de-status-option:hover {
  background: rgba(255, 255, 255, 0.05);
}

/* Load More button */
.de-load-more-container {
  display: flex;
  justify-content: center;
  margin-top: 1rem;
}

.de-load-more-btn {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  color: var(--text-primary);
  font-family: 'Outfit', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.de-load-more-btn:hover {
  border-color: var(--primary);
  background: var(--primary-hover);
  color: #fff;
  transform: translateY(-1px);
}

/* Loading state spinner */
.de-loading-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 4rem;
  color: var(--text-secondary);
  gap: 1rem;
}

.de-loading-state .spinner {
  animation: rotateSpinner 1s linear infinite;
  color: var(--primary);
}

@keyframes rotateSpinner {
  100% {
    transform: rotate(360deg);
  }
}

/* Library Header */
.de-library-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--card-border);
  padding-bottom: 0.5rem;
  margin-top: 0.5rem;
}

.de-section-title {
  font-family: 'Outfit', sans-serif;
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
}

.de-filter-status {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

/* MOCK INTERVIEW MODE STYLE */
.de-mock-setup-card,
.de-mock-active-card,
.de-mock-summary-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 2rem;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  box-shadow: var(--glass-shadow);
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  max-width: 720px;
  margin: 1rem auto;
}

.mock-setup-header {
  display: flex;
  align-items: center;
  color: var(--primary);
  gap: 0.75rem;
}

.mock-setup-header h3 {
  font-family: 'Outfit', sans-serif;
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
}

.de-form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  text-align: left;
}

.de-form-group label {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.de-select {
  padding: 0.75rem 1rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  font-family: var(--font-family);
  font-size: 0.9rem;
  color: var(--text-primary);
  cursor: pointer;
  outline: none;
  box-shadow: var(--glass-shadow);
  transition: all 0.2s ease;
}

.de-select:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.15);
}

.mock-active-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  padding-bottom: 0.75rem;
}

.mock-meta {
  display: flex;
  gap: 0.5rem;
}

.de-badge-cat {
  background: rgba(168, 85, 247, 0.15);
  color: #c084fc;
  border: 1px solid rgba(168, 85, 247, 0.25);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
}

.de-badge-diff {
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 600;
}

.de-badge-diff.easy {
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
  border: 1px solid rgba(16, 185, 129, 0.25);
}

.de-badge-diff.medium {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
  border: 1px solid rgba(245, 158, 11, 0.25);
}

.de-badge-diff.hard {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
  border: 1px solid rgba(239, 68, 68, 0.25);
}

.mock-progress {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.mock-question-section {
  text-align: center;
  padding: 1rem 0;
}

.mock-quote-icon {
  font-family: 'Space Grotesk', Georgia, serif;
  font-size: 3rem;
  color: var(--primary);
  opacity: 0.3;
  line-height: 1;
  margin-bottom: 0.25rem;
}

.mock-question-text {
  font-family: 'Outfit', sans-serif;
  font-size: 1.35rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.4;
  margin: 0;
}

/* Timer progress bar */
.de-mock-timer-container {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.de-mock-timer-bar-bg {
  flex: 1;
  height: 6px;
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 3px;
  overflow: hidden;
}

.de-mock-timer-bar {
  height: 100%;
  width: 100%;
  background: linear-gradient(90deg, #a855f7, #ec4899);
  border-radius: 3px;
  transition: width 1s linear, background-color 0.25s ease;
}

.de-mock-timer-text {
  font-family: 'Space Grotesk', 'Outfit', sans-serif;
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
  min-width: 32px;
  text-align: right;
}

/* Suggested answer block */
.de-mock-answer-section {
  text-align: left;
  border-top: 1px solid rgba(255,255,255,0.06);
  padding-top: 1rem;
}

.de-mock-answer-section h4 {
  font-family: 'Outfit', sans-serif;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 0;
  margin-bottom: 0.75rem;
}

.de-mock-answer-content {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--text-secondary);
  min-height: 80px;
  transition: all 0.3s ease;
}

.de-mock-answer-content.blurred {
  filter: blur(8px) grayscale(0.5);
  user-select: none;
  pointer-events: none;
  opacity: 0.35;
}

.mock-active-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Mock Summary completion styles */
.de-mock-summary-card {
  text-align: center;
  align-items: center;
}

.summary-success-icon {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, #10b981, #059669);
  color: #fff;
  font-size: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 0.5rem;
  box-shadow: 0 0 16px rgba(16, 185, 129, 0.4);
}

.de-mock-summary-card h3 {
  font-family: 'Outfit', sans-serif;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0;
}

.summary-stats-box {
  display: flex;
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 1.25rem 2.5rem;
  margin: 0.5rem 0;
}

.summary-stat {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.summary-stat .val {
  font-family: 'Space Grotesk', 'Outfit', sans-serif;
  font-size: 2.2rem;
  font-weight: 700;
  color: var(--primary);
}

.summary-stat .lbl {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

/* Responsive DE layout tweaks */
@media (max-width: 900px) {
  .de-dashboard-row {
    grid-template-columns: 1fr;
  }
  
  .de-search-row {
    grid-template-columns: 1fr;
  }

  .de-difficulty-chips {
    justify-content: center;
  }

  .de-mock-setup-card,
  .de-mock-active-card,
  .de-mock-summary-card {
    padding: 1.25rem;
  }
}

/* Key Concepts Glossary Accordion Styles */
.concept-accordion-card {
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  transition: all 0.25s ease;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

.concept-accordion-card:hover {
  transform: translateY(-2px);
  background: rgba(108, 92, 231, 0.04);
  border-color: var(--primary-light);
  box-shadow: 0 10px 15px -3px rgba(108, 92, 231, 0.1), 0 4px 6px -2px rgba(108, 92, 231, 0.05);
}

.concept-accordion-card.active {
  background: rgba(108, 92, 231, 0.02);
  border-color: var(--primary);
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

.concept-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  padding: 1.2rem;
  width: 100%;
  user-select: none;
}

.concept-card-header-left {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.concept-term {
  margin: 0;
  font-family: 'Space Grotesk', 'Outfit', sans-serif;
  font-size: 1.15rem;
  font-weight: 650;
  color: var(--text-primary);
}

.concept-card-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  width: 100%;
}

.concept-card-body-inner {
  padding: 0 1.2rem 1.2rem 1.2rem;
  border-top: 1px solid var(--card-border);
  padding-top: 1rem;
}

.concept-label {
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 0.75rem;
  margin-bottom: 0.35rem;
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.concept-label:first-child {
  margin-top: 0;
}

.concept-definition {
  margin: 0 0 1rem 0;
  color: var(--text-primary);
  font-size: 0.95rem;
  line-height: 1.5;
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
}

.concept-explanation {
  margin: 0 0 1rem 0;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.55;
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
}

.concept-key-points {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.55;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
}

.concept-key-points li::marker {
  color: var(--primary);
}

/* ──────────────────────────────────────────────────────────────────
   DE Cheat Sheet Integration Styling
   ────────────────────────────────────────────────────────────────── */

:root {
  --python: #3b82f6;
  --python-dim: rgba(59, 130, 246, 0.12);
  --python-glow: rgba(59, 130, 246, 0.2);
  
  --mssql: #e11d48;
  --mssql-dim: rgba(225, 29, 72, 0.12);
  --mssql-glow: rgba(225, 29, 72, 0.2);
  
  --pyspark: #f97316;
  --pyspark-dim: rgba(249, 115, 22, 0.12);
  --pyspark-glow: rgba(249, 115, 22, 0.2);
  
  --sparksql: #8b5cf6;
  --sparksql-dim: rgba(139, 92, 246, 0.12);
  --sparksql-glow: rgba(139, 92, 246, 0.2);

  --beginner: #10b981;
  --beginner-dim: rgba(16, 185, 129, 0.12);
  --intermediate: #3b82f6;
  --intermediate-dim: rgba(59, 130, 246, 0.12);
  --advanced: #f59e0b;
  --advanced-dim: rgba(245, 158, 11, 0.12);
  --architect: #ec4899;
  --architect-dim: rgba(236, 72, 153, 0.12);
}

/* Specific Topic Chip active states */
.topic-chip[data-lang="python"].active {
  background: var(--python-dim) !important;
  color: var(--python) !important;
  border-color: rgba(59, 130, 246, 0.4) !important;
  box-shadow: 0 0 15px var(--python-glow) !important;
}
.topic-chip[data-lang="mssql"].active {
  background: var(--mssql-dim) !important;
  color: var(--mssql) !important;
  border-color: rgba(225, 29, 72, 0.4) !important;
  box-shadow: 0 0 15px var(--mssql-glow) !important;
}
.topic-chip[data-lang="pyspark"].active {
  background: var(--pyspark-dim) !important;
  color: var(--pyspark) !important;
  border-color: rgba(249, 115, 22, 0.4) !important;
  box-shadow: 0 0 15px var(--pyspark-glow) !important;
}
.topic-chip[data-lang="sparksql"].active {
  background: var(--sparksql-dim) !important;
  color: var(--sparksql) !important;
  border-color: rgba(139, 92, 246, 0.4) !important;
  box-shadow: 0 0 15px var(--sparksql-glow) !important;
}

/* Cheat Sheet Cards Grid */
.cheatsheet-grid {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Level Section Headers */
.level-section {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.level-section-header {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 1.5rem 0 0.5rem;
}

.level-section-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  border: 1.5px solid;
  white-space: nowrap;
}
.lsb-beginner     { color: var(--beginner); border-color: rgba(16,185,129,0.4); background: var(--beginner-dim); }
.lsb-intermediate { color: var(--intermediate); border-color: rgba(59,130,246,0.4); background: var(--intermediate-dim); }
.lsb-advanced     { color: var(--advanced); border-color: rgba(245,158,11,0.4); background: var(--advanced-dim); }
.lsb-architect    { color: var(--architect); border-color: rgba(236,72,153,0.4); background: var(--architect-dim); }

.level-section-line {
  flex: 1;
  height: 1px;
  background: var(--card-border);
}

.level-section-count {
  font-size: 0.75rem;
  color: var(--text-secondary);
  opacity: 0.8;
  white-space: nowrap;
}

.concepts-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(500px, 100%), 1fr));
  gap: 1rem;
  align-items: start;
}

@media (max-width: 1250px) {
  .concepts-grid {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  }
}

@media (max-width: 600px) {
  .concepts-grid {
    grid-template-columns: 1fr;
  }
}

/* Cheat Sheet Card */
.concept-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  box-shadow: var(--glass-shadow);
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
}

.concept-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2.5px;
  opacity: 0;
  transition: opacity 0.3s;
}

.concept-card.python::before  { background: linear-gradient(90deg, var(--python), #60a5fa); }
.concept-card.mssql::before   { background: linear-gradient(90deg, var(--mssql), #f43f5e); }
.concept-card.pyspark::before { background: linear-gradient(90deg, var(--pyspark), #fbbf24); }
.concept-card.sparksql::before{ background: linear-gradient(90deg, var(--sparksql), #a78bfa); }

.concept-card:hover {
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.35);
}

.concept-card:hover::before {
  opacity: 1;
}

/* Card Header */
.card-header {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 1.1rem 1.25rem 0.9rem;
  cursor: pointer;
  user-select: none;
}

.card-num {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 800;
  font-family: var(--font-family);
  flex-shrink: 0;
  margin-top: 1px;
}
.python  .card-num { background: var(--python-dim); color: var(--python); }
.mssql   .card-num { background: var(--mssql-dim); color: var(--mssql); }
.pyspark .card-num { background: var(--pyspark-dim); color: var(--pyspark); }
.sparksql .card-num { background: var(--sparksql-dim); color: var(--sparksql); }

.card-meta {
  flex: 1;
  min-width: 0;
}

.card-title {
  font-size: 1rem;
  font-weight: 650;
  color: var(--text-primary);
  line-height: 1.3;
  margin-bottom: 6px;
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.tag {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: 999px;
  border: 1px solid;
}
.tag-level {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}
.tag-level.beginner     { color: var(--beginner); border-color: rgba(16,185,129,0.3); background: var(--beginner-dim); }
.tag-level.intermediate { color: var(--intermediate); border-color: rgba(59,130,246,0.3); background: var(--intermediate-dim); }
.tag-level.advanced     { color: var(--advanced); border-color: rgba(245,158,11,0.3); background: var(--advanced-dim); }
.tag-level.architect    { color: var(--architect); border-color: rgba(236,72,153,0.3); background: var(--architect-dim); }

.tag-category {
  color: var(--text-secondary);
  border-color: var(--card-border);
  background: rgba(255, 255, 255, 0.03);
  opacity: 0.8;
}

.card-chevron {
  flex-shrink: 0;
  color: var(--text-secondary);
  opacity: 0.6;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  margin-top: 4px;
}

.concept-card.open .card-chevron {
  transform: rotate(180deg);
}

/* Card Description */
.card-description {
  padding: 0 1.25rem 0.9rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.55;
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
}

/* Card Body (collapsible) */
.card-body {
  display: none;
  flex-direction: column;
}

.concept-card.open .card-body {
  display: flex;
}

/* Use Case Banner */
.use-case-banner {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 1.25rem;
  background: rgba(99, 102, 241, 0.04);
  border-left: 3px solid var(--accent);
  border-radius: 4px;
  margin: 12px 1.25rem;
}

.theme-light .use-case-banner {
  background: rgba(108, 92, 231, 0.05);
}

.uc-icon {
  font-size: 0.95rem;
  flex-shrink: 0;
  margin-top: 2px;
}

.uc-label {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-secondary);
  opacity: 0.6;
  margin-bottom: 2px;
}
.uc-text {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
}

/* Code Block */
.code-wrapper {
  position: relative;
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 8px;
  overflow: hidden;
  margin: 0 1.25rem 1.25rem;
  box-sizing: border-box;
}

.code-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 1.25rem;
  border-bottom: 1px solid var(--card-border);
}

.code-lang-badge {
  font-size: 0.65rem;
  font-weight: 700;
  font-family: monospace;
  padding: 2px 6px;
  border-radius: 4px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-secondary);
}
.theme-light .code-lang-badge {
  background: rgba(0, 0, 0, 0.06);
  color: var(--text-secondary);
}
.python  .code-lang-badge, .code-wrapper.python .code-lang-badge { background: var(--python-dim); color: var(--python); }
.mssql   .code-lang-badge, .code-wrapper.mssql .code-lang-badge { background: var(--mssql-dim); color: var(--mssql); }
.pyspark .code-lang-badge, .code-wrapper.pyspark .code-lang-badge { background: var(--pyspark-dim); color: var(--pyspark); }
.sparksql .code-lang-badge, .code-wrapper.sparksql .code-lang-badge { background: var(--sparksql-dim); color: var(--sparksql); }

.copy-btn {
  display: flex;
  align-items: center;
  gap: 5px;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 6px;
  padding: 3px 8px;
  cursor: pointer;
  font-family: var(--font-family);
  transition: all 0.2s;
}
.copy-btn:hover {
  color: var(--text-primary);
  background: var(--card-border);
}
.copy-btn.copied {
  color: var(--beginner) !important;
  border-color: rgba(16, 185, 129, 0.4) !important;
}

pre.code-block {
  margin: 0;
  padding: 12px 1.25rem;
  overflow-x: auto;
  font-family: 'JetBrains Mono', Consolas, Monaco, monospace;
  font-size: 0.82rem;
  line-height: 1.6;
  color: #e2e8f0;
  scrollbar-width: thin;
  /* Fix M: Prevent code blocks from overflowing card on mobile */
  max-width: 100%;
  box-sizing: border-box;
  word-break: break-all;
  white-space: pre-wrap;
}

.theme-light pre.code-block {
  color: var(--text-primary) !important;
}

pre.code-block::-webkit-scrollbar {
  height: 6px;
}
pre.code-block::-webkit-scrollbar-track {
  background: transparent;
}
pre.code-block::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 3px;
}
pre.code-block::-webkit-scrollbar-thumb:hover {
  background: rgba(255, 255, 255, 0.3);
}

.theme-light pre.code-block::-webkit-scrollbar-thumb {
  background: rgba(0, 0, 0, 0.15) !important;
}
.theme-light pre.code-block::-webkit-scrollbar-thumb:hover {
  background: rgba(0, 0, 0, 0.3) !important;
}

/* Ensure no double lines or text wrap on nested code element */
.code-block code,
pre.code-block code,
.code-wrapper pre code {
  color: inherit !important;
  background: transparent !important;
  padding: 0 !important;
  border: none !important;
  border-radius: 0 !important;
  word-break: normal !important;
  white-space: pre !important;
  display: block;
}

/* Notes Section */
.card-notes {
  padding: 12px 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.notes-label {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-secondary);
  opacity: 0.6;
  margin-bottom: 2px;
}

.note-item {
  display: flex;
  align-items: flex-start;
  gap: 8px;
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.5;
  word-wrap: break-word;
  overflow-wrap: break-word;
  word-break: break-word;
}

.note-bullet {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  margin-top: 6px;
  flex-shrink: 0;
}
.python  .note-bullet { background: var(--python); }
.mssql   .note-bullet { background: var(--mssql); }
.pyspark .note-bullet { background: var(--pyspark); }
.sparksql .note-bullet { background: var(--sparksql); }

/* Progress bar segmentation */
.prog-beginner     { background: var(--beginner); }
.prog-intermediate { background: var(--intermediate); }
.prog-advanced     { background: var(--advanced); }
.prog-architect    { background: var(--architect); }

/* Search Highlight */
.search-highlight {
  background: rgba(251, 191, 36, 0.22);
  color: #f59e0b;
  border-radius: 2px;
  padding: 0 1px;
}

/* Empty / Error state */
.empty-state {
  text-align: center;
  padding: 4rem 2rem;
  color: var(--text-secondary);
  opacity: 0.7;
}

.empty-state .empty-icon {
  font-size: 2.5rem;
  margin-bottom: 0.75rem;
}

.empty-state h3 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 4px;
  color: var(--text-primary);
}

.empty-state p {
  font-size: 0.85rem;
}

/* Comparison Table formatting */
.comp-table tr {
  border-bottom: 1px solid var(--card-border);
}
.comp-table tr:last-child {
  border-bottom: none;
}
.comp-table tr:hover td {
  background: rgba(255, 255, 255, 0.015);
}
.comp-table td {
  padding: 12px 16px;
  vertical-align: top;
  line-height: 1.5;
  color: var(--text-secondary);
}
.comp-table td:first-child {
  font-weight: 600;
  color: var(--text-primary);
}
.comp-check { color: var(--accent); }
.comp-x     { color: var(--danger); }
.comp-part  { color: var(--warning); }

/* =======================================================================
   COMPREHENSIVE MOBILE OPTIMIZATIONS — v1.1.0
   All view-specific overrides consolidated below this line.
   Breakpoints: 900px (tablet), 600px (mobile), 400px (small mobile)
   ======================================================================= */

/* -----------------------------------------------------------------------
   A. GLOBAL LAYOUT — main-content safe area + page header
   ----------------------------------------------------------------------- */
@media (max-width: 900px) {
  .main-content {
    padding: 1.25rem;
    padding-top: calc(60px + 1.25rem);
    /* Safe area support for devices with notch/home bar */
    padding-bottom: calc(100px + env(safe-area-inset-bottom, 0px));
    height: auto;
    overflow-y: visible;
    overflow-x: hidden;
    max-width: 100%;
    box-sizing: border-box;
  }

  /* Prevent any child from overflowing the viewport on mobile */
  .main-content > * {
    max-width: 100%;
    box-sizing: border-box;
  }

  .page-header {
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
  }

  .page-title {
    font-size: 1.6rem;
  }

  .page-subtitle {
    font-size: 0.9rem;
  }

  /* Scroll-to-top button — avoid overlap with bottom nav */
  .scroll-to-top-btn {
    bottom: calc(68px + 1rem + env(safe-area-inset-bottom, 0px));
    right: 1rem;
    width: 40px;
    height: 40px;
  }
}

@media (max-width: 600px) {
  .main-content {
    padding: 1rem;
    padding-top: calc(60px + 1rem);
    padding-bottom: calc(100px + env(safe-area-inset-bottom, 0px));
  }

  .page-title {
    font-size: 1.35rem;
  }
}

/* -----------------------------------------------------------------------
   B. FILTER BARS — stack on mobile across all views
   ----------------------------------------------------------------------- */
@media (max-width: 900px) {
  .filter-bar {
    flex-direction: column;
    align-items: stretch;
  }

  .filter-bar .search-input-wrapper {
    width: 100%;
  }

  .filter-bar .filter-select,
  .filter-bar .filter-dropdown {
    width: 100%;
  }

  .filter-bar .control-group {
    justify-content: flex-end;
  }

  /* Topics/chips scrollbar — ensure smooth horizontal scroll on touch */
  .topics-scrollbar {
    -webkit-overflow-scrolling: touch;
    padding-bottom: 0.5rem;
    gap: 0.4rem;
  }

  .topic-chip {
    padding: 0.4rem 0.85rem;
    font-size: 0.8rem;
  }
}

/* -----------------------------------------------------------------------
   C. DASHBOARD VIEW
   ----------------------------------------------------------------------- */
@media (max-width: 900px) {
  .stats-card {
    padding: 1rem;
  }

  .stats-title {
    font-size: 1.1rem;
  }

  .stats-badge {
    font-size: 0.6rem;
  }
}

/* -----------------------------------------------------------------------
   D. NICHE PRACTICE VIEW — sidebar & controls
   ----------------------------------------------------------------------- */
@media (max-width: 1200px) {
  .practice-container {
    grid-template-columns: 1fr;
    height: auto;
    gap: 1rem;
  }

  .practice-controls-row {
    flex-wrap: wrap;
    gap: 0.75rem;
  }

  /* Convert sidebar to horizontal scroll bar */
  .practice-sidebar {
    max-height: none;
    height: auto;
    flex-direction: row;
    overflow-x: auto;
    overflow-y: hidden;
    -webkit-overflow-scrolling: touch;
    padding: 0.75rem;
    gap: 0.5rem;
    border-radius: 12px;
    scrollbar-width: none;
  }

  .practice-sidebar::-webkit-scrollbar {
    display: none;
  }

  .practice-sidebar-title {
    display: none;
  }

  .practice-q-list {
    flex-direction: row;
    gap: 0.5rem;
    flex-wrap: nowrap;
    width: max-content;
  }

  .practice-q-item {
    flex-shrink: 0;
    min-width: 160px;
    max-width: 220px;
  }

  .practice-card-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }

  .practice-card-niche {
    font-size: 1.05rem;
  }

  .status-updater-row {
    flex-wrap: wrap;
  }

  .status-selector-label {
    width: 100%;
  }

  .dialog-status-selector {
    flex-wrap: wrap;
    gap: 0.4rem;
  }

  .flashcard-q p {
    font-size: 1rem;
  }
}

@media (max-width: 600px) {
  .practice-controls-row {
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
  }

  .practice-controls-row .status-updater-row,
  .practice-controls-row .practice-nav-group {
    justify-content: space-between;
    width: 100%;
  }

  .practice-nav-group {
    justify-content: space-between;
  }
}

/* -----------------------------------------------------------------------
   E. GCC DIRECTORY VIEW — table, controls, risk cards
   ----------------------------------------------------------------------- */
@media (max-width: 900px) {
  .gcc-risk-definitions {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }

  .gcc-controls {
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
  }

  .gcc-search-box {
    max-width: 100%;
    min-width: 0;
    width: 100%;
  }

  .gcc-filter-chips {
    justify-content: flex-start;
    overflow-x: auto;
    flex-wrap: nowrap;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    padding-bottom: 0.25rem;
  }

  .gcc-filter-chips::-webkit-scrollbar {
    display: none;
  }

  /* Table — ensure horizontal scroll on mobile */
  .gcc-table-wrapper {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .gcc-table {
    min-width: 700px; /* Force scroll instead of squishing */
  }

  .gcc-table th,
  .gcc-table td {
    padding: 0.75rem 0.85rem;
    font-size: 0.8rem;
  }

  /* Hide the justification column text on smallest screens (still scrollable) */
  .gcc-table .justification {
    min-width: 180px;
    max-width: 240px;
    font-size: 0.78rem;
  }
}

/* -----------------------------------------------------------------------
   F. PYSPARK CURRICULUM VIEW
   ----------------------------------------------------------------------- */
@media (max-width: 1150px) {
  .pyspark-phase-nav,
  .sparksql-phase-nav {
    gap: 0.4rem;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    flex-wrap: nowrap;
  }

  .pyspark-phase-nav::-webkit-scrollbar,
  .sparksql-phase-nav::-webkit-scrollbar {
    display: none;
  }

  .pyspark-phase-btn,
  .sparksql-phase-btn {
    flex-shrink: 0;
  }
}

@media (max-width: 900px) {
  .pyspark-phase-btn,
  .sparksql-phase-btn {
    padding: 0.45rem 0.75rem;
  }

  .pyspark-phase-btn .phase-label,
  .sparksql-phase-btn .phase-label {
    display: none;
  }

  .pyspark-phase-header,
  .sparksql-phase-header {
    flex-direction: column;
    gap: 0.75rem;
  }

  .level-card-header {
    gap: 0.75rem;
    padding: 0.85rem 1rem;
  }

  .level-title {
    font-size: 0.88rem;
  }

  .level-tag {
    white-space: normal;
  }

  .summary-grid {
    grid-template-columns: 1fr;
  }

  .pyspark-header-meta,
  .sparksql-header-meta {
    flex-wrap: wrap;
    gap: 0.4rem;
  }
}

/* -----------------------------------------------------------------------
   G. GENERAL DE PREP VIEW — mode toggle, stats, search
   ----------------------------------------------------------------------- */
@media (max-width: 1150px) {
  .de-dashboard-row {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 900px) {

  .de-search-row {
    grid-template-columns: 1fr;
  }

  .de-difficulty-chips {
    justify-content: flex-start;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    flex-wrap: nowrap;
  }

  .de-difficulty-chips::-webkit-scrollbar {
    display: none;
  }

  .de-diff-chip {
    flex-shrink: 0;
    white-space: nowrap;
  }

  .de-mock-setup-card,
  .de-mock-active-card,
  .de-mock-summary-card {
    padding: 1.25rem;
    margin: 0;
  }

  .de-mode-toggles {
    width: 100%;
    justify-content: stretch;
  }

  .de-mode-btn {
    flex: 1;
    justify-content: center;
    font-size: 0.82rem;
    padding: 0.5rem 0.6rem;
  }

  .de-stats-grid {
    grid-template-columns: 1fr 1fr;
  }

  .summary-stats-box {
    padding: 1rem 1.25rem;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
  }

  .mock-active-footer {
    flex-direction: column;
    gap: 0.75rem;
    align-items: stretch;
  }

  .mock-active-footer .control-btn {
    width: 100%;
    justify-content: center;
  }

  .de-library-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
  }
}

@media (max-width: 480px) {
  .de-stats-grid {
    grid-template-columns: 1fr;
  }

  .mock-question-text {
    font-size: 1.1rem;
  }
}

/* -----------------------------------------------------------------------
   H. KEY CONCEPTS VIEW
   ----------------------------------------------------------------------- */
@media (max-width: 900px) {
  .concept-term {
    font-size: 1rem;
  }

  .concept-card-header {
    padding: 1rem;
  }

  .concept-card-body-inner {
    padding: 0 1rem 1rem 1rem;
  }
}

/* -----------------------------------------------------------------------
   I. CODE DEEPDIVE VIEW — comparison table + code blocks
   ----------------------------------------------------------------------- */
@media (max-width: 900px) {
  /* Comparison table horizontal scroll */
  .comp-table-wrapper,
  [class*="comparison"],
  #cheatsheet-comparison-container {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }

  .comp-table {
    min-width: 480px;
  }

  .comp-table td {
    padding: 10px 12px;
    font-size: 0.82rem;
  }

  /* Code block — reduce padding on mobile */
  pre.code-block {
    padding: 10px 1rem;
    font-size: 0.78rem;
  }

  .code-toolbar {
    padding: 6px 1rem;
  }

  /* Language chip nav — already a scrollbar but ensure touch-friendly */
  #cheatsheet-lang-nav {
    -webkit-overflow-scrolling: touch;
    padding-bottom: 0.5rem;
  }

  /* Level section headers — tighten on mobile */
  .level-section-header {
    padding: 1rem 0 0.4rem;
    gap: 8px;
  }

  .level-section-badge {
    padding: 4px 10px;
    font-size: 0.72rem;
  }

  .level-section-count {
    font-size: 0.7rem;
  }
}

/* -----------------------------------------------------------------------
   J. SPARK GUIDE VIEW — simulator, memory mapper overrides
   ----------------------------------------------------------------------- */
@media (max-width: 900px) {
  /* Contain the Tailwind container so it never overflows mobile viewport */
  #view-spark .container {
    max-width: 100% !important;
    width: 100% !important;
    padding-left: 0 !important;
    padding-right: 0 !important;
    overflow-x: hidden;
  }

  /* All sections within Spark must not overflow */
  #view-spark section {
    max-width: 100%;
    overflow-x: hidden;
    box-sizing: border-box;
  }

  #view-spark [class*="col-span"] {
    width: 100% !important;
    max-width: 100% !important;
    margin-bottom: 1.25rem;
  }

  /* Memory mapper sliders — ensure they don't overflow */
  #view-spark input[type="range"] {
    width: 100%;
  }

  /* Make the memory bar text smaller on mobile */
  #view-spark [id^="bar-"] {
    font-size: 0.6rem !important;
  }

  /* Simulator select and run button — stack on mobile */
  #simulator-flow-type {
    width: 100%;
  }

  /* Clamp padding of cards and sections on mobile */
  #view-spark .p-6,
  #view-spark .md\:p-8,
  #view-spark [class*="p-6"],
  #view-spark [class*="p-8"] {
    padding: 1.25rem !important;
  }

  #view-spark .mb-12,
  #view-spark [class*="mb-12"] {
    margin-bottom: 1.5rem !important;
  }

  /* Clamp typography of inner headings */
  #view-spark h2.text-2xl,
  #view-spark h2:not(.page-title) {
    font-size: 1.35rem !important;
  }

  #view-spark h3.text-2xl {
    font-size: 1.2rem !important;
  }
}

@media (max-width: 600px) {
  #view-spark [class*="grid-cols-3"] {
    grid-template-columns: 1fr !important;
    gap: 0.75rem !important;
  }

  #view-spark .p-6,
  #view-spark .md\:p-8,
  #view-spark [class*="p-6"],
  #view-spark [class*="p-8"] {
    padding: 1rem !important;
  }

  #view-spark .mb-12,
  #view-spark [class*="mb-12"] {
    margin-bottom: 1rem !important;
  }

  #view-spark h2.text-2xl,
  #view-spark h2:not(.page-title) {
    font-size: 1.2rem !important;
  }

  #view-spark h3.text-2xl {
    font-size: 1.1rem !important;
  }
}

/* -----------------------------------------------------------------------
   K. CONCEPT EXPLAINER VIEW — filter bar & accordion
   ----------------------------------------------------------------------- */
@media (max-width: 900px) {
  #explainer-accordion .accordion-header {
    font-size: 0.92rem;
    padding: 0.7rem 1rem;
  }

  .accordion-inner {
    padding: 0 1rem 0;
  }

  /* Cards grid inside accordion — dynamic column count on tablets */
  .cards-grid {
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  }
}

@media (max-width: 600px) {
  .cards-grid {
    grid-template-columns: 1fr;
  }
}

/* -----------------------------------------------------------------------
   L. TOUCH TARGETS — improve tap targets for all interactive elements
   ----------------------------------------------------------------------- */
@media (max-width: 900px) {
  button,
  .control-btn,
  .status-btn,
  .gcc-chip,
  .topic-chip,
  .de-diff-chip,
  .nav-btn {
    touch-action: manipulation;
  }

  /* Ensure minimum 44px tap target height */
  .control-btn,
  .status-btn,
  .gcc-chip {
    min-height: 40px;
  }
}

/* -----------------------------------------------------------------------
   M. SITE FOOTER — compact on mobile
   ----------------------------------------------------------------------- */
@media (max-width: 900px) {
  .site-footer {
    margin-top: 2rem;
    padding: 1.5rem 1rem 1rem !important;
    font-size: 0.72rem;
  }
}

/* -----------------------------------------------------------------------
   N. COMPARISON SECTION SPACING
   ----------------------------------------------------------------------- */
.comparison-section {
  margin-top: 3.5rem;
  margin-bottom: 2rem;
}

@media (max-width: 900px) {
  .comparison-section {
    margin-top: 2rem !important;
    margin-bottom: 1.5rem !important;
  }
}

@media (max-width: 600px) {
  .comparison-section {
    margin-top: 1.5rem !important;
    margin-bottom: 1rem !important;
  }
}

/* =======================================================================
   O. GLOBAL RESPONSIVE CONTAINMENT & TEXT WRAPPING OVERRIDES (v1.5.0)
   Resolves all horizontal overflows, layout breaks, and text wrapping.
   ======================================================================= */

/* 1. Global text wrapping guarantee across all text elements */
p, li, td, th,
.dialog-body, .dialog-answer-text,
.concept-term, .concept-definition, .concept-explanation, .concept-impact,
.level-scenario p, .flashcard-q p, .flashcard-a-text, .best-practice-card p, .lexicon-card p,
.stats-title, .page-title, .page-subtitle, .practice-sidebar-title, .level-title, .level-tag {
  white-space: normal !important;
  overflow-wrap: break-word !important;
  word-wrap: break-word !important;
  word-break: break-word !important;
  text-overflow: initial !important;
  overflow: visible !important;
  height: auto !important;
  min-width: 0 !important;
}

code, pre {
  word-wrap: break-word !important;
  overflow-wrap: break-word !important;
  word-break: break-word !important;
}

/* 2. Global container bounds clamps */
body, html, #app-container, .main-content, .page-view, .container, .grid, .flex, .sidebar, .mobile-top-bar, .mobile-bottom-nav {
  max-width: 100% !important;
  box-sizing: border-box !important;
}

/* 3. Constrain all card elements to prevent horizontal sizing expansion */
.stats-card,
.concept-card,
.concept-accordion-card,
.niche-launcher-card,
.pyspark-level-card,
.sparksql-level-card,
.stats-card,
.concept-card,
.concept-accordion-card,
.niche-launcher-card,
.lexicon-card,
.best-practice-card,
.dialog-box,
.practice-sidebar,
.flashcard-card,
.flashcard,
.gcc-tip-card,
.de-mock-setup-card,
.de-mock-active-card,
.de-mock-summary-card,
.de-difficulty-chips,
.level-card-header,
.level-card-body,
.level-meta,
.launcher-info,
.dialog-body,
.dialog-answer-text,
.dialog-title-container {
  min-width: 0 !important;
  max-width: 100% !important;
  box-sizing: border-box !important;
}

/* 4. Enforce scrolling behavior on horizontal navigation/scrollbars */
.topics-scrollbar,
.gcc-filter-chips,
.de-difficulty-chips,
.pyspark-phase-nav,
.sparksql-phase-nav,
.mobile-nav-scroll {
  max-width: 100% !important;
  width: 100% !important;
  box-sizing: border-box !important;
  min-width: 0 !important;
}

/* 5. MathJax and formula layout containment */
mjx-container, .MathJax, .MathJax_Display, .MJX_TEX, mjx-math, .MathJax_Math, .MathJax_MathML, math {
  max-width: 100% !important;
  width: 100% !important;
  overflow-x: auto !important;
  overflow-y: hidden !important;
  display: block !important;
  min-width: 0 !important;
}

/* 6. Code wrappers and preformatted text containment */
.code-wrapper, pre.code-block {
  max-width: 100% !important;
  min-width: 0 !important;
  overflow-x: auto !important;
  box-sizing: border-box !important;
}

/* 7. Responsive adjustments for stats cards */
@media (max-width: 480px) {
  .stats-header {
    flex-direction: column !important;
    align-items: flex-start !important;
    gap: 0.5rem !important;
  }
}

/* 8. Personalised Prep View Styles */
.personalised-counter {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  font-family: 'Space Grotesk', sans-serif;
  margin-left: auto;
}

@media (max-width: 600px) {
  .personalised-counter {
    margin-left: 0;
    width: 100%;
    margin-top: 0.25rem;
  }
}

/* 9. Unified Spark Hub Subviews & Transitions */
.spark-hub-content-container {
  position: relative;
  width: 100%;
}

.spark-hub-subview {
  animation: sparkSubviewFadeIn 0.4s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes sparkSubviewFadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================================
   SPARK ENGINE ARCHITECTURE — PREMIUM REDESIGN
   ============================================================ */

/* --- Color Tokens for Spark Theme --- */
:root {
  --spark-orange: #FF6B35;
  --spark-amber: #FFB347;
  --spark-red: #E25822;
  --spark-glow: rgba(255, 107, 53, 0.18);
  --spark-glow-strong: rgba(255, 107, 53, 0.35);
  --spark-deep: #0d1117;
  --spark-panel: rgba(13, 17, 23, 0.92);
  --executor-blue: #4f9cf9;
  --executor-glow: rgba(79, 156, 249, 0.25);
  --output-green: #22c55e;
  --output-glow: rgba(34, 197, 94, 0.22);
}

/* --- Hero Banner --- */
.spark-hero-banner {
  position: relative;
  overflow: hidden;
  border-radius: 20px;
  padding: 2.5rem 2rem 2rem;
  margin-bottom: 2rem;
  background: linear-gradient(135deg, #0a0e1a 0%, #1a0a2e 40%, #0d1a0a 100%);
  border: 1px solid rgba(255, 107, 53, 0.3);
  box-shadow: 0 0 60px rgba(255, 107, 53, 0.12), 0 20px 60px rgba(0,0,0,0.5);
}

.spark-hero-banner::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 80% at 80% 50%, rgba(255, 107, 53, 0.12) 0%, transparent 70%),
              radial-gradient(ellipse 50% 60% at 10% 80%, rgba(79, 156, 249, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

.spark-hero-banner::after {
  content: '';
  position: absolute;
  top: -2px;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, transparent, #FF6B35, #FFB347, #FF6B35, transparent);
  border-radius: 20px 20px 0 0;
}

.spark-hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #FF6B35;
  background: rgba(255, 107, 53, 0.12);
  border: 1px solid rgba(255, 107, 53, 0.3);
  padding: 0.3rem 0.75rem;
  border-radius: 50px;
  margin-bottom: 1rem;
}

.spark-hero-title {
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 600;
  color: #ffffff;
  line-height: 1.25;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.spark-hero-title span {
  background: linear-gradient(90deg, #FF6B35, #FFB347);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.spark-hero-subtitle {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.6);
  max-width: 550px;
  line-height: 1.6;
  margin-bottom: 1.5rem;
}

.spark-hero-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.spark-hero-stat-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.72rem;
  font-weight: 600;
  color: rgba(255,255,255,0.85);
  background: rgba(255,255,255,0.07);
  border: 1px solid rgba(255,255,255,0.12);
  padding: 0.35rem 0.8rem;
  border-radius: 50px;
  backdrop-filter: blur(8px);
}

.spark-hero-stat-pill .stat-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
}

.spark-hero-icon-cluster {
  position: absolute;
  right: 2rem;
  top: 50%;
  transform: translateY(-50%);
  opacity: 0.15;
  font-size: 6rem;
  line-height: 1;
  pointer-events: none;
  filter: blur(1px);
}

/* --- Section Headers (reusable) --- */
.spark-section-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.spark-section-eyebrow {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #FF6B35;
  margin-bottom: 0.25rem;
}

.spark-section-title {
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text-primary);
  letter-spacing: -0.01em;
  line-height: 1.3;
}

.spark-section-desc {
  font-size: 0.82rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-top: 0.35rem;
  max-width: 600px;
}

/* --- Milestone Cards --- */
.spark-milestone-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.25rem;
  margin-bottom: 2rem;
}

.spark-milestone-card {
  position: relative;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 1.5rem;
  overflow: hidden;
  transition: transform 0.28s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.28s ease;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.spark-milestone-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  border-radius: 16px 16px 0 0;
}

.spark-milestone-card.color-red::before { background: linear-gradient(90deg, #E25822, #FF6B35); }
.spark-milestone-card.color-purple::before { background: linear-gradient(90deg, #7a5195, #bc5090); }
.spark-milestone-card.color-amber::before { background: linear-gradient(90deg, #d97706, #f59e0b); }

.spark-milestone-card:hover {
  transform: translateY(-5px) scale(1.01);
  box-shadow: 0 16px 40px rgba(0,0,0,0.2), 0 0 0 1px rgba(255,107,53,0.15);
}

.spark-milestone-icon-wrap {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  margin-bottom: 1rem;
}

.spark-milestone-icon-wrap.bg-red { background: rgba(226, 88, 34, 0.12); border: 1px solid rgba(226, 88, 34, 0.25); }
.spark-milestone-icon-wrap.bg-purple { background: rgba(188, 80, 144, 0.12); border: 1px solid rgba(188, 80, 144, 0.25); }
.spark-milestone-icon-wrap.bg-amber { background: rgba(245, 158, 11, 0.12); border: 1px solid rgba(245, 158, 11, 0.25); }

.spark-milestone-label {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-bottom: 0.35rem;
}

.spark-milestone-label.text-red { color: #FF6B35; }
.spark-milestone-label.text-purple { color: #bc5090; }
.spark-milestone-label.text-amber { color: #f59e0b; }

.spark-milestone-name {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.6rem;
  line-height: 1.3;
}

.spark-milestone-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* --- Section Card Container (generic wrapper) --- */
.spark-section-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 18px;
  padding: 2rem;
  margin-bottom: 2rem;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--glass-shadow);
  position: relative;
  overflow: hidden;
}

/* --- Interactive Simulator Redesign --- */
.spark-sim-panel {
  background: #0d1117;
  border: 1px solid rgba(255,107,53,0.25);
  border-radius: 14px;
  padding: 1.5rem;
  position: relative;
  overflow: hidden;
  min-height: 380px;
}

.spark-sim-panel::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 60% 80% at 50% 100%, rgba(255,107,53,0.06) 0%, transparent 70%);
  pointer-events: none;
}

.spark-sim-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}

.spark-sim-dot-row {
  display: flex;
  gap: 5px;
}

.spark-sim-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.spark-sim-dot.red { background: #ff5f56; }
.spark-sim-dot.yellow { background: #ffbd2e; }
.spark-sim-dot.green { background: #27c93f; }

.spark-sim-title-bar {
  font-size: 0.7rem;
  color: rgba(255,255,255,0.4);
  font-family: monospace;
  letter-spacing: 0.05em;
}

.spark-sim-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
  align-items: center;
  min-height: 280px;
}

.spark-sim-column {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.spark-sim-col-label {
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  text-align: center;
  margin-bottom: 0.25rem;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
}

.spark-sim-col-label.input-label {
  color: #4f9cf9;
  background: rgba(79, 156, 249, 0.1);
  border: 1px solid rgba(79, 156, 249, 0.2);
}

.spark-sim-col-label.exec-label {
  color: #FF6B35;
  background: rgba(255, 107, 53, 0.1);
  border: 1px solid rgba(255, 107, 53, 0.2);
}

.spark-sim-col-label.output-label {
  color: #22c55e;
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid rgba(34, 197, 94, 0.2);
}

.spark-partition-node {
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(79, 156, 249, 0.25);
  border-radius: 10px;
  padding: 0.6rem 0.75rem;
  font-size: 0.72rem;
  color: #c9d1d9;
  font-family: monospace;
  text-align: center;
  position: relative;
  overflow: hidden;
  transition: border-color 0.3s, box-shadow 0.3s, background 0.3s;
}

.spark-partition-node::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: #4f9cf9;
  border-radius: 10px 0 0 10px;
}

.spark-partition-node small {
  display: block;
  font-size: 0.6rem;
  color: rgba(255,255,255,0.35);
  margin-top: 0.2rem;
}

.spark-executor-node {
  background: rgba(255, 107, 53, 0.06);
  border: 2px solid rgba(255, 107, 53, 0.4);
  border-radius: 12px;
  padding: 0.85rem 0.75rem;
  text-align: center;
  font-size: 0.75rem;
  color: #FF6B35;
  font-weight: 600;
  position: relative;
  overflow: hidden;
  transition: all 0.3s;
}

.spark-executor-node::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 0%, rgba(255,107,53,0.15) 0%, transparent 70%);
  pointer-events: none;
}

.spark-executor-status {
  display: block;
  font-size: 0.6rem;
  font-weight: 400;
  color: rgba(255,107,53,0.6);
  margin-top: 0.2rem;
  font-family: monospace;
}

.spark-output-node {
  background: rgba(34, 197, 94, 0.04);
  border: 1px solid rgba(34, 197, 94, 0.25);
  border-radius: 10px;
  padding: 0.6rem 0.75rem;
  font-size: 0.72rem;
  color: #c9d1d9;
  font-family: monospace;
  text-align: center;
  position: relative;
  overflow: hidden;
  transition: border-color 0.3s, box-shadow 0.3s, background 0.3s;
}

.spark-output-node::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: #22c55e;
  border-radius: 10px 0 0 10px;
}

.spark-output-ready {
  display: block;
  font-size: 0.6rem;
  color: #22c55e;
  margin-top: 0.2rem;
  font-family: monospace;
}

.spark-sim-log-panel {
  background: #161b22;
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 14px;
  padding: 1.25rem 1.5rem;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.spark-log-eyebrow {
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #FFB347;
  margin-bottom: 0.5rem;
}

.spark-log-title {
  font-size: 1rem;
  font-weight: 600;
  color: #ffffff;
  line-height: 1.3;
  margin-bottom: 0.75rem;
}

.spark-log-text {
  font-size: 0.75rem;
  color: rgba(201, 209, 217, 0.85);
  line-height: 1.65;
}

.spark-log-insight {
  background: rgba(255, 179, 71, 0.08);
  border: 1px solid rgba(255, 179, 71, 0.25);
  border-radius: 8px;
  padding: 0.6rem 0.75rem;
  font-size: 0.72rem;
  color: #FFB347;
  line-height: 1.5;
  margin-top: 0.75rem;
}

.spark-log-stats {
  border-top: 1px solid rgba(255,255,255,0.06);
  padding-top: 0.75rem;
  margin-top: 0.75rem;
}

.spark-log-stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.72rem;
  color: rgba(255,255,255,0.5);
  margin-top: 0.35rem;
}

.spark-log-stat-value {
  font-family: monospace;
  font-weight: 600;
  color: #FFB347;
}

/* --- Sim Controls --- */
.spark-sim-controls {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  align-items: center;
  margin-bottom: 1rem;
}

.spark-sim-select {
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,107,53,0.3);
  border-radius: 10px;
  padding: 0.5rem 0.85rem;
  font-size: 0.75rem;
  font-weight: 500;
  color: rgba(255,255,255,0.8);
  outline: none;
  cursor: pointer;
  transition: border-color 0.2s;
}

.spark-sim-select:focus, .spark-sim-select:hover {
  border-color: #FF6B35;
}

.spark-sim-run-btn {
  background: linear-gradient(135deg, #FF6B35, #E25822);
  border: none;
  border-radius: 10px;
  padding: 0.5rem 1.1rem;
  font-size: 0.75rem;
  font-weight: 700;
  color: white;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  transition: transform 0.15s, box-shadow 0.15s;
  box-shadow: 0 4px 12px rgba(255,107,53,0.3);
  letter-spacing: 0.02em;
}

.spark-sim-run-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(255,107,53,0.45);
}

.spark-sim-run-btn:active {
  transform: scale(0.97);
}

/* --- Memory Allocator Redesign --- */
/* Donut Chart styles */
.spark-memory-chart-container {
  display: flex;
  flex-direction: row;
  align-items: center;
  gap: 2rem;
  margin-top: 1rem;
  margin-bottom: 1.5rem;
}

.spark-memory-pie-chart {
  position: relative;
  width: 180px;
  height: 180px;
  border-radius: 50%;
  background: conic-gradient(#ef4444 0% 10%, #7c3aed 10% 45%, #d97706 45% 80%, #0d9488 80% 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3), var(--glass-shadow);
  flex-shrink: 0;
  border: 1px solid var(--card-border);
  transition: background 0.3s ease;
}

.spark-memory-pie-center {
  width: 115px;
  height: 115px;
  border-radius: 50%;
  background: var(--card-bg);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.4);
  border: 1px solid var(--card-border);
}

.spark-memory-chart-container .spark-mem-legend {
  grid-template-columns: repeat(2, 1fr) !important;
  flex-grow: 1;
  width: 100%;
}

@media (max-width: 900px) {
  .spark-memory-chart-container {
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
  }
}

.spark-mem-legend {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.6rem;
  margin-top: 0.5rem;
}

@media (min-width: 640px) {
  .spark-mem-legend {
    grid-template-columns: repeat(4, 1fr);
  }
}

.spark-mem-legend-item {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 0.7rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.spark-mem-legend-header {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.spark-mem-legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 3px;
  flex-shrink: 0;
}

.spark-mem-legend-label {
  font-size: 0.62rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-secondary);
}

.spark-mem-legend-value {
  font-family: monospace;
  font-size: 0.88rem;
  font-weight: 700;
}

.spark-mem-legend-hint {
  font-size: 0.62rem;
  color: var(--text-secondary);
  line-height: 1.45;
}

/* --- Sliders Styled --- */
.spark-slider-group {
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 1rem 1.2rem;
  margin-bottom: 0.75rem;
}

.spark-slider-label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-primary);
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.spark-slider-value {
  font-family: monospace;
  color: #FF6B35;
  background: rgba(255,107,53,0.1);
  border: 1px solid rgba(255,107,53,0.2);
  padding: 0.1rem 0.5rem;
  border-radius: 5px;
  font-size: 0.75rem;
}

.spark-slider-hint {
  font-size: 0.62rem;
  color: var(--text-secondary);
  margin-top: 0.4rem;
}

/* --- Lexicon Grid Redesign --- */
.spark-lexicon-card {
  padding: 1.1rem 1.25rem;
  border-radius: 14px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
  position: relative;
  overflow: hidden;
}

.spark-lexicon-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.15);
  border-color: rgba(255,107,53,0.4);
}

.spark-lexicon-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
}

.spark-lexicon-card[data-category="engine"]::before { background: linear-gradient(90deg, #4f9cf9, #7c3aed); }
.spark-lexicon-card[data-category="optimization"]::before { background: linear-gradient(90deg, #bc5090, #ef4444); }
.spark-lexicon-card[data-category="memory"]::before { background: linear-gradient(90deg, #d97706, #f59e0b); }
.spark-lexicon-card[data-category="streaming"]::before { background: linear-gradient(90deg, #ef4444, #f97316); }

.spark-lexicon-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
}

.spark-lex-cat-badge {
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.spark-lex-type-badge {
  font-size: 0.6rem;
  font-weight: 700;
  font-family: monospace;
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  letter-spacing: 0.04em;
}

.spark-lexicon-term {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
  line-height: 1.3;
}

.spark-lexicon-def {
  font-size: 0.78rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --- Polyglot Panel Fix (dark mode safe) --- */
.spark-polyglot-panel {
  padding: 1rem 1.1rem;
  border-radius: 12px;
  border: 1px solid var(--card-border);
  background: var(--item-bg);
  transition: border-color 0.2s;
}

.spark-polyglot-panel:hover {
  border-color: rgba(255,107,53,0.35);
}

.spark-polyglot-lang-title {
  font-weight: 600;
  font-size: 0.85rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.4rem;
  margin-bottom: 0.4rem;
}

.spark-polyglot-lang-desc {
  font-size: 0.76rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --- Ecosystem Cards --- */
.spark-ecosystem-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 1.5rem;
  position: relative;
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.spark-ecosystem-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
}

.spark-ecosystem-card.eco-sql::before { background: linear-gradient(90deg, #4f9cf9, #6366f1); }
.spark-ecosystem-card.eco-streaming::before { background: linear-gradient(90deg, #ef4444, #f97316); }
.spark-ecosystem-card.eco-mllib::before { background: linear-gradient(90deg, #d97706, #f59e0b); }
.spark-ecosystem-card.eco-graphx::before { background: linear-gradient(90deg, #10b981, #22c55e); }

.spark-ecosystem-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 32px rgba(0,0,0,0.18);
}

.spark-ecosystem-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.85rem;
}

.spark-eco-icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
}

.spark-eco-icon.sql-icon { background: rgba(79, 156, 249, 0.12); border: 1px solid rgba(79, 156, 249, 0.25); }
.spark-eco-icon.stream-icon { background: rgba(239, 68, 68, 0.12); border: 1px solid rgba(239, 68, 68, 0.25); }
.spark-eco-icon.ml-icon { background: rgba(217, 119, 6, 0.12); border: 1px solid rgba(217, 119, 6, 0.25); }
.spark-eco-icon.graph-icon { background: rgba(16, 185, 129, 0.12); border: 1px solid rgba(16, 185, 129, 0.25); }

.spark-eco-badge {
  font-size: 0.62rem;
  font-weight: 700;
  padding: 0.2rem 0.6rem;
  border-radius: 50px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.spark-eco-badge.structured { background: rgba(79, 156, 249, 0.12); color: #4f9cf9; border: 1px solid rgba(79, 156, 249, 0.25); }
.spark-eco-badge.incremental { background: rgba(239, 68, 68, 0.12); color: #f87171; border: 1px solid rgba(239, 68, 68, 0.25); }
.spark-eco-badge.iterative { background: rgba(217, 119, 6, 0.12); color: #fbbf24; border: 1px solid rgba(217, 119, 6, 0.25); }
.spark-eco-badge.topology { background: rgba(16, 185, 129, 0.12); color: #34d399; border: 1px solid rgba(16, 185, 129, 0.25); }

.spark-ecosystem-name {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.spark-ecosystem-desc {
  font-size: 0.78rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1rem;
}

/* --- Best Practice Cards Redesign --- */
.spark-bp-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1rem;
}

.spark-bp-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 14px;
  padding: 1.25rem;
  position: relative;
  overflow: hidden;
  transition: transform 0.22s ease, box-shadow 0.22s ease;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.spark-bp-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 28px rgba(0,0,0,0.15);
}

.spark-bp-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  bottom: 0;
  border-radius: 14px 0 0 14px;
}

.spark-bp-card.bp-1::after { background: linear-gradient(180deg, #4f9cf9, #7c3aed); }
.spark-bp-card.bp-2::after { background: linear-gradient(180deg, #7c3aed, #bc5090); }
.spark-bp-card.bp-3::after { background: linear-gradient(180deg, #bc5090, #ef4444); }
.spark-bp-card.bp-4::after { background: linear-gradient(180deg, #ef4444, #f97316); }
.spark-bp-card.bp-5::after { background: linear-gradient(180deg, #f97316, #FFB347); }
.spark-bp-card.bp-6::after { background: linear-gradient(180deg, #FFB347, #22c55e); }

.spark-bp-top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 0.6rem;
}

.spark-bp-icon {
  width: 36px;
  height: 36px;
  border-radius: 9px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  flex-shrink: 0;
}

.spark-bp-num {
  font-size: 0.65rem;
  font-weight: 700;
  color: var(--text-secondary);
  font-family: monospace;
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 5px;
  padding: 0.15rem 0.4rem;
}

.spark-bp-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
  line-height: 1.3;
}

.spark-bp-desc {
  font-size: 0.77rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --- Modern Enhancements (AQE/DPP) Cards --- */
.spark-enhancement-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 1.5rem;
  position: relative;
  overflow: hidden;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  backdrop-filter: blur(12px);
}

.spark-enhancement-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 30px rgba(0,0,0,0.18);
}

.spark-enhancement-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  margin-bottom: 0.85rem;
  gap: 0.5rem;
}

.spark-enhancement-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.3;
}

.spark-enhancement-badge {
  font-size: 0.62rem;
  font-weight: 700;
  padding: 0.2rem 0.6rem;
  border-radius: 50px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  white-space: nowrap;
  flex-shrink: 0;
}

.spark-badge-runtime { background: rgba(122, 81, 149, 0.15); color: var(--primary); border: 1px solid rgba(122,81,149,0.3); }
.spark-badge-lakehouse { background: rgba(79, 156, 249, 0.12); color: #4f9cf9; border: 1px solid rgba(79, 156, 249, 0.25); }

.spark-enhancement-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 1rem;
}

.spark-code-pill {
  background: #0d1117;
  border: 1px solid rgba(255,255,255,0.1);
  border-radius: 8px;
  padding: 0.7rem 1rem;
  font-size: 0.72rem;
  font-family: monospace;
  color: #86efac;
  line-height: 1.7;
}

/* --- Animations for Simulator nodes --- */
@keyframes sparkNodePulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(255,107,53,0); }
  50% { box-shadow: 0 0 0 6px rgba(255,107,53,0.2); }
}

@keyframes sparkFlowIn {
  from { opacity: 0; transform: translateX(-12px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes sparkFlowOut {
  from { opacity: 0; transform: translateX(12px); }
  to { opacity: 1; transform: translateX(0); }
}

.spark-executor-node.active {
  border-color: #FF6B35;
  background: rgba(255, 107, 53, 0.12);
  animation: sparkNodePulse 1.5s infinite;
}

.spark-partition-node.processing {
  border-color: rgba(255, 107, 53, 0.6);
  background: rgba(255, 107, 53, 0.06);
}

.spark-output-node.done {
  border-color: rgba(34, 197, 94, 0.6);
  background: rgba(34, 197, 94, 0.06);
  box-shadow: 0 0 12px rgba(34, 197, 94, 0.15);
}

/* --- Responsive Layout helpers for Spark sections --- */
.spark-two-col {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 1024px) {
  .spark-two-col { grid-template-columns: 5fr 4fr; }
  .spark-sim-grid { grid-template-columns: 1fr 1.4fr 1fr; }
  .spark-hero-icon-cluster { display: block; }
}

@media (max-width: 768px) {
  .spark-hero-icon-cluster { display: none; }
  .spark-sim-grid { grid-template-columns: 1fr; gap: 0.5rem; }
  .spark-section-card { padding: 1.25rem; }
  .spark-hero-banner { padding: 1.5rem 1.25rem; }
}

/* --- Category filter buttons for lexicon --- */
.spark-filter-btn {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.35rem 0.85rem;
  border-radius: 50px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.2s ease;
}

.spark-filter-btn:hover, .spark-filter-btn.active {
  background: rgba(255,107,53,0.12);
  border-color: rgba(255,107,53,0.4);
  color: #FF6B35;
}

/* --- Premium Theme, Layout, and Visual Polish Overrides --- */

/* 1. Responsive Desktop 2-Column Grid for Simulator Layout */
#sim-layout-grid {
  display: grid !important;
  grid-template-columns: 1fr;
  gap: 1.25rem;
}
@media (min-width: 1024px) {
  #sim-layout-grid {
    grid-template-columns: 1.8fr 1fr !important;
  }
}

/* 2. Card Border Radiuses Standardisation */
.spark-milestone-card,
.spark-section-card,
.spark-ecosystem-card,
.spark-enhancement-card {
  border-radius: 16px !important;
}
.spark-sim-panel,
.spark-sim-log-panel,
.spark-lexicon-card,
.spark-bp-card {
  border-radius: 14px !important;
}
.spark-polyglot-panel {
  border-radius: 12px !important;
}

/* 3. Light Theme Overrides & Accessibility Contrast Improvements */

/* Spark Hero Banner Light Mode */
.theme-light .spark-hero-banner {
  background: linear-gradient(135deg, hsl(15, 100%, 96%) 0%, hsl(245, 100%, 97%) 50%, hsl(160, 100%, 96%) 100%) !important;
  border-color: rgba(255, 107, 53, 0.22) !important;
  box-shadow: 0 10px 30px rgba(255, 107, 53, 0.05), var(--glass-shadow) !important;
}
.theme-light .spark-hero-banner::before {
  background: radial-gradient(ellipse 70% 80% at 80% 50%, rgba(255, 107, 53, 0.06) 0%, transparent 70%),
              radial-gradient(ellipse 50% 60% at 10% 80%, rgba(79, 156, 249, 0.04) 0%, transparent 70%) !important;
}
.theme-light .spark-hero-banner::after {
  background: linear-gradient(90deg, transparent, #FF6B35, #FFB347, #FF6B35, transparent) !important;
}
.theme-light .spark-hero-title {
  color: var(--text-primary) !important;
}
.theme-light .spark-hero-subtitle {
  color: var(--text-secondary) !important;
}
.theme-light .spark-hero-stat-pill {
  color: var(--text-primary) !important;
  background: rgba(255, 255, 255, 0.65) !important;
  border-color: rgba(0, 0, 0, 0.08) !important;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.02) !important;
}

/* Milestone text contrast */
.theme-light .spark-milestone-label.text-red { color: var(--cat-spark) !important; }
.theme-light .spark-milestone-label.text-purple { color: var(--cat-de) !important; }
.theme-light .spark-milestone-label.text-amber { color: var(--cat-dl) !important; }

/* Ecosystem badge contrast */
.theme-light .spark-eco-badge.structured { color: var(--cat-adf) !important; background: rgba(79, 156, 249, 0.08) !important; border-color: rgba(79, 156, 249, 0.15) !important; }
.theme-light .spark-eco-badge.incremental { color: var(--cat-spark) !important; background: rgba(239, 68, 68, 0.08) !important; border-color: rgba(239, 68, 68, 0.15) !important; }
.theme-light .spark-eco-badge.iterative { color: var(--cat-dl) !important; background: rgba(217, 119, 6, 0.08) !important; border-color: rgba(217, 119, 6, 0.15) !important; }
.theme-light .spark-eco-badge.topology { color: var(--cat-excel) !important; background: rgba(16, 185, 129, 0.08) !important; border-color: rgba(16, 185, 129, 0.15) !important; }
.theme-light .spark-badge-lakehouse { color: var(--cat-adf) !important; background: rgba(79, 156, 249, 0.08) !important; border-color: rgba(79, 156, 249, 0.15) !important; }

/* Lexicon badges and buttons contrast */
.theme-light .spark-lexicon-card[data-category="engine"] .spark-lex-cat-badge { color: var(--cat-adf) !important; }
.theme-light .spark-lexicon-card[data-category="optimization"] .spark-lex-cat-badge { color: var(--cat-de) !important; }
.theme-light .spark-lexicon-card[data-category="memory"] .spark-lex-cat-badge { color: var(--cat-dl) !important; }
.theme-light .spark-lexicon-card[data-category="streaming"] .spark-lex-cat-badge { color: var(--cat-spark) !important; }

.theme-light .spark-lexicon-card[data-category="engine"] .spark-lex-type-badge { color: var(--cat-adf) !important; background: rgba(79, 156, 249, 0.08) !important; }
.theme-light .spark-lexicon-card[data-category="optimization"] .spark-lex-type-badge { color: var(--cat-excel) !important; background: rgba(34, 197, 94, 0.08) !important; }
.theme-light .spark-lexicon-card[data-category="memory"] .spark-lex-type-badge { color: var(--cat-dl) !important; background: rgba(245, 158, 11, 0.08) !important; }
.theme-light .spark-lexicon-card[data-category="streaming"] .spark-lex-type-badge { color: var(--cat-spark) !important; background: rgba(239, 68, 68, 0.08) !important; }

.theme-light .spark-filter-btn:hover, .theme-light .spark-filter-btn.active {
  background: rgba(255, 107, 53, 0.08) !important;
  border-color: rgba(255, 107, 53, 0.3) !important;
  color: var(--cat-spark) !important;
}

/* 4. Interactive Sandbox Custom Layout Styles */
.spark-sandbox-header {
  background: linear-gradient(135deg, rgba(255, 107, 53, 0.08) 0%, rgba(188, 80, 144, 0.08) 100%);
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--card-border);
}
.theme-dark .spark-sandbox-header {
  background: linear-gradient(135deg, rgba(255, 107, 53, 0.15) 0%, rgba(188, 80, 144, 0.15) 100%);
}
.spark-sandbox-badge {
  display: inline-block;
  background: rgba(255, 107, 53, 0.1);
  color: #FF6B35;
  border: 1px solid rgba(255, 107, 53, 0.25);
  font-size: 0.65rem;
  font-weight: 700;
  padding: 0.25rem 0.65rem;
  border-radius: 50px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.spark-sandbox-title {
  font-size: 1.3rem;
  font-weight: 600;
  margin-top: 0.6rem;
  color: var(--text-primary);
}
.spark-sandbox-desc {
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
  line-height: 1.5;
}
.spark-sandbox-tabs {
  display: flex;
  background: var(--item-bg);
  border-bottom: 1px solid var(--card-border);
}
.spark-sandbox-tab-btn {
  flex: 1;
  padding: 0.85rem 1rem;
  font-weight: 600;
  font-size: 0.8rem;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-secondary);
  background: transparent;
  cursor: pointer;
  transition: all 0.2s;
  text-align: center;
}
.spark-sandbox-tab-btn:hover {
  color: var(--text-primary);
  background: rgba(255, 107, 53, 0.04);
}
.spark-sandbox-tab-btn.active {
  border-bottom-color: #FF6B35 !important;
  color: #FF6B35 !important;
}
.spark-sandbox-run-btn {
  background: linear-gradient(135deg, #FF6B35, #E25822);
  color: white;
  font-weight: 600;
  padding: 0.6rem 1.25rem;
  border-radius: 10px;
  font-size: 0.82rem;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  transition: all 0.2s ease;
  box-shadow: 0 4px 12px rgba(255,107,53,0.25);
}
.spark-sandbox-run-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(255,107,53,0.4);
}
.spark-sandbox-run-btn:active {
  transform: scale(0.98);
}
.spark-sandbox-output {
  margin-top: 1.5rem;
  border-top: 1px solid var(--card-border);
  padding-top: 1.25rem;
}
.spark-sandbox-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 3rem 1rem;
  gap: 0.75rem;
}
.spark-sandbox-spinner {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 2px solid transparent;
  border-bottom-color: #FF6B35;
  animation: rotateSpinner 0.8s linear infinite;
}
.spark-sandbox-loading-status {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* 5. Live Green Dot Pulse Animation */
@keyframes liveDotPulse {
  0%, 100% { transform: scale(1); opacity: 1; box-shadow: 0 0 0 0 rgba(34, 197, 94, 0.7); }
  50% { transform: scale(1.1); opacity: 0.8; box-shadow: 0 0 0 6px rgba(34, 197, 94, 0); }
}
.spark-live-dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #22c55e;
  animation: liveDotPulse 1.8s infinite ease-in-out;
}

/* 6. Markdown Output Formatting Classes */
.markdown-h2 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 1.25rem;
  margin-bottom: 0.5rem;
  border-bottom: 1px solid var(--card-border);
  padding-bottom: 0.25rem;
}
.markdown-h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 1rem;
  margin-bottom: 0.4rem;
}
.markdown-h4 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 0.75rem;
  margin-bottom: 0.3rem;
}
.markdown-ul {
  list-style-type: disc;
  list-style-position: inside;
  margin: 0.5rem 0 0.5rem 1rem;
  padding-left: 0.5rem;
  font-size: 0.82rem;
  color: var(--text-secondary);
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

/* ==========================================
   Q&A COMMAND CENTER EXPLORER REVAMP STYLES
   ========================================== */

/* Difficulty filter bar — top banner shared across all Prep Hub sub-pages */
.qa-difficulty-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}

/* Title label inside the difficulty bar */
.qa-difficulty-bar .qa-filter-group-title {
  margin: 0;
  display: flex;
  align-items: center;
  gap: 8px;
}

/* Inline pill selector reset — sits inside the difficulty bar */
.qa-pill-selector--inline {
  margin: 0;
  padding: 0;
  border: none;
  background: none;
}

/* Compact secondary control buttons (Expand All / Collapse All) */
.control-btn--compact {
  padding: 0.4rem 0.8rem;
  font-size: 0.75rem;
  border-radius: 6px;
  cursor: pointer;
  border: 1px solid var(--card-border);
  background: rgba(255, 255, 255, 0.02);
  color: var(--text-secondary);
}

/* Subtab Segment selector inside Prep Hub */
.prep-hub-subnav {
  display: flex !important; /* Force override display hidden */
  gap: 0.5rem;
  padding: 0.35rem;
  background: rgba(255, 255, 255, 0.015);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  width: fit-content;
  max-width: 100%;
  overflow-x: auto;
  margin-bottom: 2rem !important;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
}

.prep-hub-subnav::-webkit-scrollbar {
  display: none;
}

.prep-hub-subnav .topic-chip {
  margin: 0 !important;
  background: transparent;
  border: none;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: 8px;
  padding: 0.5rem 1.15rem;
  font-size: 0.88rem;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  white-space: nowrap;
}

.prep-hub-subnav .topic-chip:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.04);
}

.prep-hub-subnav .topic-chip.active {
  background: var(--primary);
  color: #fff !important;
  box-shadow: 0 4px 12px rgba(108, 92, 231, 0.35);
}

/* Horizontal Filter Stack — replaces old 2-column sidebar layout */
.qa-hfilter-stack {
  display: flex;
  flex-direction: column;
  gap: 0;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: var(--glass-shadow);
  margin-bottom: 1.25rem;
}

.qa-hfilter-row {
  display: flex;
  align-items: center;
  padding: 0.7rem 1.25rem;
  border-bottom: 1px solid var(--card-border);
  gap: 0.75rem;
  min-height: 52px;
}

.qa-hfilter-row:last-child {
  border-bottom: none;
}

.qa-hfilter-row .qa-search-wrapper {
  flex: 1;
}

.qa-hfilter-chips-row {
  align-items: center;
  flex-wrap: nowrap;
}

.qa-hfilter-label {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 700;
  color: var(--text-secondary);
  white-space: nowrap;
  flex-shrink: 0;
  min-width: 56px;
  opacity: 0.7;
}

.qa-chips-scroll {
  display: flex;
  flex-direction: row;
  flex-wrap: nowrap;
  gap: 0.4rem;
  overflow-x: auto;
  /* Fix O: iOS momentum scrolling for filter chip containers */
  -webkit-overflow-scrolling: touch;
  scroll-behavior: smooth;
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding-bottom: 2px;
  flex: 1;
}

.qa-chips-scroll::-webkit-scrollbar {
  display: none;
}

/* Filter Chips Row also overrides qa-sidebar-list when inside hfilter */
.qa-hfilter-chips-row .qa-sidebar-list {
  flex-direction: row !important;
  flex-wrap: nowrap !important;
  overflow-x: auto !important;
  -webkit-overflow-scrolling: touch !important;
  max-height: none !important;
  padding-right: 0 !important;
  scrollbar-width: none;
  -ms-overflow-style: none;
  flex: 1;
}

.qa-hfilter-chips-row .qa-sidebar-list::-webkit-scrollbar {
  display: none;
}

/* On mobile viewports, keep filters scrollable horizontally (no-wrap) to save vertical space */
@media (max-width: 600px) {
  .qa-hfilter-row {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
    padding: 0.85rem 1rem;
    width: 100%;
  }
  .qa-hfilter-label {
    min-width: 0;
    margin-bottom: 0.2rem;
  }
  .qa-chips-scroll {
    flex-wrap: nowrap !important;
    overflow-x: auto !important;
    width: 100%;
    -webkit-overflow-scrolling: touch;
  }
  .qa-hfilter-chips-row .qa-sidebar-list {
    flex-wrap: nowrap !important;
    overflow-x: auto !important;
    width: 100%;
    -webkit-overflow-scrolling: touch;
  }
}

/* Horizontal Filter Chips Bar — scrollable pill row for DB/domain/topic filters */
.filter-chips-bar {
  display: flex;
  flex-wrap: nowrap;
  gap: 0.5rem;
  overflow-x: auto;
  padding: 0.15rem 0 0.5rem 0;
  scrollbar-width: none;
  -ms-overflow-style: none;
  margin-bottom: 0.75rem;
}

.filter-chips-bar::-webkit-scrollbar {
  display: none;
}

.filter-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.35rem 0.85rem;
  border-radius: 99px;
  border: 1px solid var(--card-border);
  background: var(--card-bg);
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.18s ease;
  flex-shrink: 0;
}

.filter-chip:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: rgba(108, 92, 231, 0.07);
}

.filter-chip.active {
  background: rgba(108, 92, 231, 0.18);
  border-color: var(--primary);
  color: var(--primary);
  font-weight: 700;
}

.filter-chip .chip-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: rgba(108, 92, 231, 0.2);
  color: var(--primary);
  font-size: 0.7rem;
  font-weight: 700;
  min-width: 18px;
  height: 18px;
  border-radius: 99px;
  padding: 0 5px;
}

.filter-chip.active .chip-badge {
  background: var(--primary);
  color: #fff;
}

/* Search row inside difficulty bar */
.qa-search-row {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}

.qa-search-row .qa-search-wrapper {
  flex: 1;
  min-width: 200px;
}

/* Filter section label */
.filter-bar-label {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  font-weight: 700;
  color: var(--text-secondary);
  margin-bottom: 0.35rem;
  padding: 0;
}

/* Filter Group Cards */
.qa-filter-group-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 1.25rem;
  box-shadow: var(--glass-shadow);
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
}

.qa-filter-group-title {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-weight: 700;
  color: var(--primary);
  margin: 0 0 1rem 0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Search Box custom styles */
.qa-search-wrapper {
  position: relative;
  display: flex;
  align-items: center;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 0.25rem 0.75rem;
  transition: all 0.3s ease;
}

.qa-search-wrapper:focus-within {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.15);
  background: rgba(0, 0, 0, 0.3);
}

.qa-search-input {
  width: 100%;
  background: none;
  border: none;
  color: var(--text-primary);
  padding: 0.6rem 0.5rem;
  font-size: 0.92rem;
  outline: none;
}

/* Filter items styling — horizontal chip mode by default */
.qa-sidebar-list {
  display: flex;
  flex-direction: row;
  flex-wrap: nowrap;
  gap: 0.4rem;
  overflow-x: auto;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.qa-sidebar-list::-webkit-scrollbar {
  display: none;
}

.qa-sidebar-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: auto;
  flex-shrink: 0;
  padding: 0.42rem 0.9rem;
  border-radius: 99px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid rgba(255, 255, 255, 0.07);
  color: var(--text-secondary);
  font-size: 0.82rem;
  font-weight: 500;
  white-space: nowrap;
  cursor: pointer;
  transition: all 0.2s ease;
  gap: 6px;
}

.qa-sidebar-btn:hover {
  background: rgba(255, 255, 255, 0.04);
  border-color: var(--card-border);
  color: var(--text-primary);
}

.qa-sidebar-btn.active {
  background: rgba(108, 92, 231, 0.12);
  border-color: rgba(108, 92, 231, 0.4);
  color: var(--primary) !important;
  font-weight: 600;
}

.qa-btn-count-badge {
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-secondary);
  font-size: 0.7rem;
  padding: 2px 7px;
  border-radius: 99px;
  font-weight: 600;
}

.qa-sidebar-btn.active .qa-btn-count-badge {
  background: rgba(108, 92, 231, 0.2);
  color: var(--primary);
}



/* Horizontal pill selectors */
.qa-pill-selector {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.qa-pill-btn {
  padding: 0.5rem 0.85rem;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--card-border);
  color: var(--text-secondary);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  gap: 6px;
}

.qa-pill-btn:hover {
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-primary);
}

.qa-pill-btn.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff !important;
  box-shadow: 0 4px 10px rgba(108, 92, 231, 0.25);
}

.qa-pill-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
}

/* Q&A Results Panel */
.qa-results-stream {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.qa-stream-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  padding: 0.75rem 1.25rem;
  box-shadow: var(--glass-shadow);
}

.qa-stream-count {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* Expandable Section Accordions */
.unified-section-wrapper {
  background: var(--card-bg) !important;
  box-shadow: var(--glass-shadow);
  border: 1px solid var(--card-border) !important;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  /* Fix P: Improve paint performance for off-screen sections */
  content-visibility: auto;
  contain-intrinsic-size: 0 400px;
}

.unified-section-wrapper:hover {
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
  border-color: rgba(255, 255, 255, 0.16) !important;
}

.unified-section-header {
  background: transparent !important;
}

.unified-section-header:hover {
  background: rgba(255, 255, 255, 0.02) !important;
}

.unified-section-body {
  border-top: 1px solid var(--card-border) !important;
  background: rgba(0, 0, 0, 0.15) !important;
}

/* Fix Q: GPU-accelerated card transitions — use transform instead of layout-triggering properties */
.concept-accordion-card {
  background: rgba(255, 255, 255, 0.015);
  border: 1px solid var(--card-border);
  border-radius: 12px;
  overflow: hidden;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
  will-change: transform;
}

.concept-accordion-card:hover {
  border-color: rgba(255, 255, 255, 0.28);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
  transform: translateY(-2px);
  background: rgba(255, 255, 255, 0.025);
}

.concept-accordion-card.expanded {
  border-color: var(--primary);
  box-shadow: 0 4px 20px rgba(108, 92, 231, 0.15);
  background: rgba(255, 255, 255, 0.02);
  transform: none;
}

.level-card-header {
  padding: 1.1rem 1.25rem !important;
  gap: 14px !important;
}

.level-card-body {
  background: rgba(0, 0, 0, 0.2) !important;
  border-top: 1px solid var(--card-border) !important;
}


/* ══════════════════════════════════════════════════════════
   UNIFIED PILL, FILTER, AND SEARCH HIGHLIGHT SYSTEM
   ══════════════════════════════════════════════════════════ */

/* Force all chip and filter button variants to have identical geometries and glassmorphic designs */
.topic-chip,
.de-diff-chip,
.gcc-chip,
.qa-sidebar-btn {
  display: inline-flex !important;
  align-items: center !important;
  justify-content: center !important;
  width: auto !important;
  flex-shrink: 0 !important;
  padding: 0.42rem 0.9rem !important;
  border-radius: 99px !important;
  background: rgba(255, 255, 255, 0.02) !important;
  border: 1px solid rgba(255, 255, 255, 0.15) !important;
  color: var(--text-secondary) !important;
  font-family: var(--font-family) !important;
  font-size: 0.82rem !important;
  font-weight: 500 !important;
  white-space: nowrap !important;
  cursor: pointer !important;
  transition: all 0.2s ease !important;
  gap: 6px !important;
  box-shadow: none !important;
  transform: none !important;
  line-height: normal !important;
}

.topic-chip:hover,
.de-diff-chip:hover,
.gcc-chip:hover,
.qa-sidebar-btn:hover {
  background: rgba(255, 255, 255, 0.04) !important;
  border-color: var(--card-border) !important;
  color: var(--text-primary) !important;
  transform: none !important;
}

/* Base default active state styling */
.topic-chip.active,
.de-diff-chip.active,
.gcc-chip.active,
.qa-sidebar-btn.active {
  background: rgba(108, 92, 231, 0.12) !important;
  border-color: rgba(108, 92, 231, 0.4) !important;
  color: var(--primary) !important;
  font-weight: 600 !important;
  box-shadow: none !important;
}

/* Specific colored highlights for Difficulty, Level, and Risk tiers */
.de-diff-chip[data-difficulty="EASY"].active,
.de-diff-chip[data-level="beginner"].active,
.de-diff-chip[data-level="easy"].active,
.qa-sidebar-btn[data-difficulty="EASY"].active,
.gcc-chip[data-filter="Low Risk"].active {
  background: rgba(34, 197, 94, 0.12) !important;
  border-color: rgba(34, 197, 94, 0.4) !important;
  color: #22c55e !important;
}

.de-diff-chip[data-difficulty="MEDIUM"].active,
.de-diff-chip[data-level="intermediate"].active,
.de-diff-chip[data-level="medium"].active,
.qa-sidebar-btn[data-difficulty="MEDIUM"].active,
.gcc-chip[data-filter="Medium Risk"].active {
  background: rgba(59, 130, 246, 0.12) !important;
  border-color: rgba(59, 130, 246, 0.4) !important;
  color: #3b82f6 !important;
}

.de-diff-chip[data-difficulty="HARD"].active,
.de-diff-chip[data-level="advanced"].active,
.de-diff-chip[data-level="hard"].active,
.qa-sidebar-btn[data-difficulty="HARD"].active,
.gcc-chip[data-filter="High Risk"].active {
  background: rgba(249, 115, 22, 0.12) !important;
  border-color: rgba(249, 115, 22, 0.4) !important;
  color: #f97316 !important;
}

.de-diff-chip[data-difficulty="ARCHITECT"].active,
.de-diff-chip[data-level="architect"].active,
.qa-sidebar-btn[data-difficulty="ARCHITECT"].active {
  background: rgba(168, 85, 247, 0.12) !important;
  border-color: rgba(168, 85, 247, 0.4) !important;
  color: #a855f7 !important;
}

/* Bullet alignment inside chips/pills */
.de-diff-chip span,
.topic-chip span,
.gcc-chip span,
.qa-sidebar-btn span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

/* Ensure bullet dot style is properly aligned and rounded */
.qa-pill-dot {
  display: inline-block;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  flex-shrink: 0;
}

/* Prep Hub Layout Custom Section Cards */
.prep-hub-content-container {
  display: flex;
  flex-direction: column;
  gap: 3rem; /* healthy spacing between stacked sections */
}

/* Make each subview a distinct, premium card */
.prep-hub-subview {
  background: rgba(255, 255, 255, 0.01);
  border: 1px solid var(--card-border);
  border-radius: 20px;
  padding: 2rem;
  box-shadow: var(--glass-shadow);
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  scroll-margin-top: 6rem; /* ensure scroll alignment leaves room for navbar/subnav */
}

.prep-hub-subview:hover {
  border-color: rgba(108, 92, 231, 0.25);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.35), 0 0 20px rgba(108, 92, 231, 0.05);
}

/* Section Header Style */
.prep-section-header {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  margin-bottom: 2rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--card-border);
}

.prep-section-header-icon {
  font-size: 2rem;
  background: rgba(108, 92, 231, 0.1);
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  border: 1px solid rgba(108, 92, 231, 0.2);
  flex-shrink: 0;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

.prep-section-header-content {
  flex: 1;
}

.prep-section-header-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0 0 0.25rem 0;
  letter-spacing: -0.025em;
  background: linear-gradient(135deg, var(--text-primary) 0%, rgba(255, 255, 255, 0.7) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.prep-section-header-desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin: 0;
  line-height: 1.4;
}

/* Unified Tags design for Question Cards */
.qa-card-tags {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
  margin-bottom: 0.75rem;
  align-items: center;
}

.qa-card-tag {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.55rem;
  border-radius: 6px;
  background: rgba(255, 255, 255, 0.04);
  color: var(--text-secondary);
  border: 1px solid var(--card-border);
  transition: all 0.2s ease;
}

/* Source-specific tag styles */
.qa-card-tag.qa-tag-source {
  background: rgba(108, 92, 231, 0.08);
  color: var(--accent);
  border-color: rgba(108, 92, 231, 0.2);
}

/* Domain tag styles */
.qa-card-tag.qa-tag-domain {
  background: rgba(255, 255, 255, 0.02);
  color: var(--text-primary);
}

/* Difficulty-specific tags */
.qa-card-tag.qa-tag-difficulty.difficulty-easy {
  color: #22c55e;
  background: rgba(34, 197, 94, 0.06);
  border-color: rgba(34, 197, 94, 0.15);
}
.qa-card-tag.qa-tag-difficulty.difficulty-medium {
  color: #3b82f6;
  background: rgba(59, 130, 246, 0.06);
  border-color: rgba(59, 130, 246, 0.15);
}
.qa-card-tag.qa-tag-difficulty.difficulty-hard {
  color: #f97316;
  background: rgba(249, 115, 22, 0.06);
  border-color: rgba(249, 115, 22, 0.15);
}
.qa-card-tag.qa-tag-difficulty.difficulty-architect {
  color: #a855f7;
  background: rgba(168, 85, 247, 0.06);
  border-color: rgba(168, 85, 247, 0.15);
}

/* Status-specific tags */
.qa-card-tag.qa-tag-status.status-mastered {
  color: #10b981;
  background: rgba(16, 185, 129, 0.08);
  border-color: rgba(16, 185, 129, 0.2);
}
.qa-card-tag.qa-tag-status.status-reviewing {
  color: #f59e0b;
  background: rgba(245, 158, 11, 0.08);
  border-color: rgba(245, 158, 11, 0.2);
}

/* ─── ANIMATION SYSTEM INTEGRATION ───────────────────────── */

/* Glass card shimmer overlay on hover */
.concept-accordion-card {
  position: relative;
  overflow: hidden;
}

.concept-accordion-card::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    105deg,
    transparent 40%,
    rgba(255, 255, 255, 0.04) 50%,
    transparent 60%
  );
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
}

.concept-accordion-card:hover::after {
  opacity: 1;
}

/* Section header title with gradient fallback */
.prep-section-header-title {
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

/* Enhanced filter stack card appearance */
.qa-hfilter-stack {
  background: var(--card-bg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.15);
}

/* Match count result bar smooth update */
.qa-stream-count {
  transition: opacity 0.25s ease;
}

/* Sidebar hover active state glow */
.nav-item.active {
  background: rgba(108, 92, 231, 0.12);
  box-shadow: inset 0 0 0 1px rgba(108, 92, 231, 0.2);
}

/* Topic chip smooth underline active indicator */
.topic-chip.active {
  position: relative;
}

.topic-chip.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 50%;
  transform: translateX(-50%);
  width: 24px;
  height: 2px;
  background: var(--primary);
  border-radius: 99px;
}

/* Main content scroll padding for reveal trigger */
.main-content {
  scroll-padding-top: 1rem;
}

/* Stats banner subtle entrance */
.stats-banner {
  animation: fadeIn 0.8s ease 0.3s both;
}

/* Premium brand icon pulse on hover */
.brand-icon:hover,
.mobile-brand-logo:hover {
  box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.3);
  transition: box-shadow 0.3s ease;
}

/* Card result stream smooth empty state */
#unified-search-container:empty::after {
  content: '';
  display: block;
  height: 2px;
}

/* Smooth opacity transition for qa-stream-count updates */
.qa-stream-header {
  transition: opacity 0.2s ease;
}

/* ============================================================
   ADDITIONAL SPARK HUB THEMING & CONSISTENCY IMPROVEMENTS
   ============================================================ */

/* Light theme adjustments for memory center */
.theme-light .spark-memory-pie-center {
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.08) !important;
}

/* Polyglot Language Tab Layout */
.spark-lang-tabs {
  display: flex;
  flex-wrap: wrap;
  background: var(--item-bg);
  border-bottom: 1px solid var(--card-border);
}
.spark-lang-tab-btn {
  padding: 0.6rem 1rem;
  font-size: 0.75rem;
  font-weight: 600;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-secondary);
  background: transparent;
  cursor: pointer;
  transition: all 0.2s;
}
.spark-lang-tab-btn:hover {
  color: var(--text-primary);
  background: rgba(255, 107, 53, 0.04);
}
.spark-lang-tab-btn.active {
  border-bottom-color: #FF6B35 !important;
  color: #FF6B35 !important;
}
.theme-light .spark-lang-tab-btn.active {
  border-bottom-color: var(--cat-spark) !important;
  color: var(--cat-spark) !important;
}

/* Code Container theme safety */
.spark-lang-code-container {
  padding: 1rem;
  background: #0d1117;
  border-radius: 0 0 12px 12px;
  transition: background 0.3s ease;
}
.theme-light .spark-lang-code-container {
  background: var(--item-bg) !important;
}
.theme-light .terminal-block {
  color: var(--text-primary) !important;
}

/* Polyglot Code Panel Header */
.spark-lang-panel-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.7rem;
  color: rgba(255, 255, 255, 0.5);
  margin-bottom: 0.5rem;
}
.theme-light .spark-lang-panel-header {
  color: var(--text-secondary) !important;
}

/* Badge colors inside the header */
.spark-lang-panel-header .badge-pyspark { color: #FFB347; font-family: monospace; }
.spark-lang-panel-header .badge-scala   { color: #4f9cf9; font-family: monospace; }
.spark-lang-panel-header .badge-sql     { color: #22c55e; font-family: monospace; }
.spark-lang-panel-header .badge-java    { color: #818cf8; font-family: monospace; }

.theme-light .spark-lang-panel-header .badge-pyspark { color: var(--cat-dl) !important; }
.theme-light .spark-lang-panel-header .badge-scala   { color: var(--cat-de) !important; }
.theme-light .spark-lang-panel-header .badge-sql     { color: var(--cat-excel) !important; }
.theme-light .spark-lang-panel-header .badge-java    { color: var(--cat-adf) !important; }

/* Light theme overrides for simulator select element */
.theme-light .spark-sim-select {
  background: var(--card-bg) !important;
  color: var(--text-primary) !important;
  border-color: var(--card-border) !important;
}
.theme-light .spark-sim-select:hover {
  border-color: var(--cat-spark) !important;
}

/* Sandbox form inputs & selects */
.spark-sandbox-select {
  width: 100%;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  padding: 0.5rem 0.85rem;
  font-size: 0.82rem;
  color: var(--text-primary);
  outline: none;
  cursor: pointer;
  transition: all 0.2s ease;
}
.spark-sandbox-select:focus, .spark-sandbox-select:hover {
  border-color: #FF6B35;
}
.spark-sandbox-textarea {
  width: 100%;
  font-size: 0.82rem;
  background: var(--card-bg);
  color: var(--text-primary);
  padding: 0.85rem;
  border-radius: 10px;
  border: 1px solid var(--card-border);
  outline: none;
  resize: vertical;
  transition: all 0.2s ease;
}
.spark-sandbox-textarea:focus, .spark-sandbox-textarea:hover {
  border-color: #FF6B35;
}
.spark-sandbox-code-textarea {
  width: 100%;
  font-family: monospace;
  font-size: 0.8rem;
  background: #0d1117;
  color: #86efac;
  padding: 1rem;
  border-radius: 10px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  outline: none;
  resize: vertical;
  transition: all 0.2s ease;
}
.spark-sandbox-code-textarea:focus {
  border-color: #FF6B35;
}
.theme-light .spark-sandbox-code-textarea {
  background: var(--item-bg) !important;
  color: var(--text-primary) !important;
  border-color: var(--card-border) !important;
}
.theme-light .spark-sandbox-code-textarea:focus {
  border-color: var(--cat-spark) !important;
}
.spark-sandbox-text-input {
  width: 100%;
  font-size: 0.82rem;
  background: var(--card-bg);
  color: var(--text-primary);
  padding: 0.85rem;
  border-radius: 10px;
  border: 1px solid var(--card-border);
  outline: none;
  transition: all 0.2s ease;
}
.spark-sandbox-text-input:focus, .spark-sandbox-text-input:hover {
  border-color: #FF6B35;
}

/* Ecosystem icon contrast theme safety */
.theme-light .spark-eco-icon.sql-icon    { background: rgba(79, 156, 249, 0.06) !important; border-color: rgba(79, 156, 249, 0.18) !important; }
.theme-light .spark-eco-icon.stream-icon { background: rgba(239, 68, 68, 0.06) !important; border-color: rgba(239, 68, 68, 0.18) !important; }
.theme-light .spark-eco-icon.ml-icon     { background: rgba(217, 119, 6, 0.06) !important; border-color: rgba(217, 119, 6, 0.18) !important; }
.theme-light .spark-eco-icon.graph-icon  { background: rgba(16, 185, 129, 0.06) !important; border-color: rgba(16, 185, 129, 0.18) !important; }

/* -----------------------------------------------------------------------
   SYNTAX COMPARISON VIEW STYLES
   ----------------------------------------------------------------------- */
.comparison-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  backdrop-filter: blur(var(--blur-radius));
  -webkit-backdrop-filter: blur(var(--blur-radius));
  box-shadow: var(--glass-shadow);
  transition: all 0.25s ease;
}

.comparison-card.hidden-comp {
  display: none !important;
}

.comparison-card-header {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
  border-bottom: 1px solid var(--card-border);
  padding-bottom: 0.75rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.comparison-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-bottom: 1.25rem;
}

@media (max-width: 1250px) {
  .comparison-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
}

.comparison-section {
  display: flex;
  flex-direction: column;
}

.comparison-section h5 {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0 0 0.5rem 0;
}

.comparison-section.lang-python h5 {
  color: #3b82f6; /* Blue for Python */
}

.comparison-section.lang-pyspark h5 {
  color: #f97316; /* Orange for PySpark */
}

.comparison-section.lang-sparksql h5 {
  color: #a855f7; /* Purple for Spark SQL */
}

.comparison-section pre {
  margin: 0;
  padding: 0.75rem 1rem;
  background: var(--item-bg);
  border: 1px solid var(--card-border);
  border-radius: 10px;
  overflow-x: auto;
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.8rem;
  line-height: 1.5;
  color: var(--text-primary);
  flex: 1;
}

.comparison-tips {
  font-size: 0.85rem;
  line-height: 1.5;
  color: var(--text-secondary);
  background: rgba(108, 92, 231, 0.04);
  border: 1px dashed rgba(108, 92, 231, 0.2);
  border-radius: 10px;
  padding: 0.85rem 1.25rem;
}

.comparison-tips strong {
  color: var(--accent);
}

/* -----------------------------------------------------------------------
   SIDEBAR MINIMIZE/EXPAND TOGGLE STYLES
   ----------------------------------------------------------------------- */
#app-container {
  display: grid;
  grid-template-columns: 280px 1fr;
  width: 100%;
  min-height: 100vh;
  transition: grid-template-columns 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

#app-container.sidebar-collapsed {
  grid-template-columns: 68px 1fr;
}

.sidebar {
  transition: padding 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  position: relative;
}

/* Sidebar Resizer drag handle styles */
.sidebar-resizer {
  position: absolute;
  top: 0;
  right: 0;
  width: 6px;
  height: 100%;
  cursor: col-resize;
  background: transparent;
  z-index: 1000;
  transition: background 0.2s ease;
}

.sidebar-resizer:hover,
.sidebar-resizer.resizing {
  background: rgba(108, 92, 231, 0.2);
}

.sidebar-collapsed .sidebar-resizer {
  display: none;
  pointer-events: none;
}

.sidebar-collapsed .sidebar {
  padding: 1.25rem 0.5rem;
}

.brand {
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

.sidebar-collapsed .brand {
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  justify-content: center !important;
}

.brand-text {
  transition: opacity 0.15s ease, width 0.15s ease, visibility 0.15s;
  opacity: 1;
  visibility: visible;
  width: auto;
}

.sidebar-collapsed .brand-text {
  opacity: 0;
  visibility: hidden;
  width: 0;
  height: 0;
  margin: 0;
  padding: 0;
  overflow: hidden;
}

.brand-icon {
  transition: width 0.3s ease, height 0.3s ease;
}

.sidebar-collapsed .brand-icon {
  width: 42px;
  height: 42px;
}

.nav-text {
  transition: opacity 0.15s ease, width 0.15s ease, visibility 0.15s;
  opacity: 1;
  visibility: visible;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-collapsed .nav-text {
  opacity: 0;
  visibility: hidden;
  width: 0;
  overflow: hidden;
  margin: 0;
}

.nav-btn {
  justify-content: flex-start;
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  min-width: 0;
}

.nav-btn svg {
  flex-shrink: 0;
}

.sidebar-collapsed .nav-btn {
  width: 42px;
  height: 42px;
  padding: 0;
  justify-content: center;
  margin: 0 auto;
}

.theme-toggle-label {
  transition: opacity 0.15s ease, width 0.15s ease, visibility 0.15s;
  opacity: 1;
  visibility: visible;
  white-space: nowrap;
}

.sidebar-collapsed .theme-toggle-label {
  opacity: 0;
  visibility: hidden;
  width: 0;
  overflow: hidden;
  margin: 0;
}

.theme-toggle-container {
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

.sidebar-collapsed .theme-toggle-container {
  background: transparent;
  padding: 0;
  border: none;
  justify-content: center;
}

.theme-toggle-btn {
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  flex-shrink: 0;
}

.sidebar-collapsed .theme-toggle-btn {
  width: 42px;
  height: 42px;
  border-radius: 10px;
  margin: 0 auto;
}

.sidebar-toggle-btn {
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  flex-shrink: 0;
}

.sidebar-toggle-btn:hover {
  color: var(--primary);
  background: rgba(108, 92, 231, 0.1);
}

.sidebar-toggle-btn svg {
  transition: transform 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

.sidebar-collapsed .sidebar-toggle-btn {
  width: 42px;
  height: 42px;
  padding: 0;
  margin: 0 auto;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.sidebar-collapsed .sidebar-toggle-btn svg {
  transform: rotate(180deg);
}

/* --- Large Desktop Screens Max-Width Constraint --- */
@media (min-width: 1600px) {
  .page-view {
    max-width: 1440px;
    margin-left: auto;
    margin-right: auto;
  }
}