/* Modern Clean Light Theme - AI Introduction CSS Design System */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800&family=Space+Grotesk:wght@400;500;600;700&display=swap');

:root {
  /* Primary Default: Elegant Soft Light Theme */
  --bg-dark: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --border-color: #e2e8f0;
  --border-glow: rgba(79, 70, 229, 0.25);
  
  --primary: #0284c7;
  --primary-glow: rgba(2, 132, 199, 0.15);
  --secondary: #4f46e5;
  --secondary-glow: rgba(79, 70, 229, 0.15);
  --accent: #e11d48;
  --success: #059669;
  --warning: #d97706;
  
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-dim: #64748b;
  
  --font-main: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-heading: 'Space Grotesk', sans-serif;
  
  --glass-backdrop: blur(16px) saturate(160%);
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-full: 9999px;
  
  --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  --card-shadow: 0 4px 20px rgba(0, 0, 0, 0.05), 0 1px 3px rgba(0, 0, 0, 0.03);
}

/* Dark Theme Variant */
[data-theme="dark"] {
  --bg-dark: #0f172a;
  --bg-card: rgba(30, 41, 59, 0.8);
  --bg-card-hover: rgba(51, 65, 85, 0.9);
  --border-color: rgba(255, 255, 255, 0.1);
  --border-glow: rgba(99, 102, 241, 0.3);
  
  --primary: #38bdf8;
  --primary-glow: rgba(56, 189, 248, 0.18);
  --secondary: #818cf8;
  --secondary-glow: rgba(129, 140, 248, 0.18);
  --accent: #f43f5e;
  --success: #10b981;
  --warning: #f59e0b;
  
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --card-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-main);
  line-height: 1.6;
  overflow-x: hidden;
  position: relative;
  min-height: 100vh;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Multi-Page Views System */
.page-view {
  display: none;
  padding-top: 5.5rem;
  padding-bottom: 5rem;
  min-height: 82vh;
}

.page-view.active {
  display: block;
  animation: fadeInPage 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

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

.page-header-banner {
  text-align: center;
  max-width: 800px;
  margin: 1.5rem auto 3rem auto;
  padding: 2.5rem 2rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--card-shadow);
}

.page-header-title {
  font-size: 2.4rem;
  font-weight: 800;
  margin-top: 0.5rem;
  margin-bottom: 0.75rem;
  color: var(--text-main);
}

.page-header-desc {
  color: var(--text-muted);
  font-size: 1.1rem;
}

/* Background Neural Canvas */
#neural-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 0;
  pointer-events: none;
  opacity: 0.45;
}

/* Typography & Gradient Text */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--text-main);
}

.gradient-text {
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* Header & Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: var(--glass-backdrop);
  -webkit-backdrop-filter: var(--glass-backdrop);
  border-bottom: 1px solid var(--border-color);
  padding: 0.9rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: var(--transition);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.03);
}

[data-theme="dark"] .navbar {
  background: rgba(15, 23, 42, 0.85);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-main);
  text-decoration: none;
}

.nav-brand .brand-icon {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 1.1rem;
}

.nav-controls {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.nav-links {
  display: flex;
  gap: 1.1rem;
  list-style: none;
}

.nav-link {
  color: var(--text-muted);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.92rem;
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.nav-link:hover, .nav-link.active {
  color: var(--primary);
  background: rgba(2, 132, 199, 0.08);
}

[data-theme="dark"] .nav-link:hover, [data-theme="dark"] .nav-link.active {
  color: var(--text-main);
  background: rgba(255, 255, 255, 0.08);
}

/* Theme Toggle Button */
.theme-toggle-btn {
  background: rgba(0, 0, 0, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: var(--transition);
}

[data-theme="dark"] .theme-toggle-btn {
  background: rgba(255, 255, 255, 0.08);
}

.theme-toggle-btn:hover {
  transform: translateY(-2px);
  border-color: var(--primary);
}

.nav-cta {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #fff;
  border: none;
  padding: 0.65rem 1.4rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: var(--transition);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: 0 4px 12px rgba(2, 132, 199, 0.2);
}

.nav-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 18px rgba(79, 70, 229, 0.25);
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-main);
  font-size: 1.5rem;
  cursor: pointer;
}

/* Layout Containers */
.container {
  max-width: 1240px;
  margin: 0 auto;
  padding: 0 1.5rem;
  position: relative;
  z-index: 1;
}

section {
  padding: 2.5rem 0;
  position: relative;
}

.section-header {
  text-align: center;
  max-width: 750px;
  margin: 0 auto 3.5rem auto;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 1rem;
  border-radius: var(--radius-full);
  background: rgba(2, 132, 199, 0.1);
  border: 1px solid rgba(2, 132, 199, 0.25);
  color: var(--primary);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.section-title {
  font-size: 2.4rem;
  font-weight: 800;
  margin-bottom: 1rem;
}

.section-desc {
  color: var(--text-muted);
  font-size: 1.05rem;
}

/* Hero Section */
.hero-section {
  padding-top: 3rem;
  padding-bottom: 3rem;
  display: flex;
  align-items: center;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 3.5rem;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(79, 70, 229, 0.1);
  border: 1px solid rgba(79, 70, 229, 0.25);
  padding: 0.4rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  color: var(--secondary);
  font-weight: 600;
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 1.5rem;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-muted);
  margin-bottom: 2.25rem;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #fff;
  padding: 0.85rem 2rem;
  border-radius: var(--radius-full);
  font-weight: 700;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  transition: var(--transition);
  border: none;
  cursor: pointer;
  box-shadow: 0 4px 15px var(--primary-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--secondary-glow);
}

.btn-secondary {
  background: #ffffff;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.85rem 2rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  transition: var(--transition);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}

[data-theme="dark"] .btn-secondary {
  background: rgba(255, 255, 255, 0.05);
}

.btn-secondary:hover {
  background: #f8fafc;
  transform: translateY(-2px);
  border-color: #cbd5e1;
}

.hero-media {
  position: relative;
}

.hero-image-card {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-color);
  box-shadow: var(--card-shadow);
  background: var(--bg-card);
}

.hero-image-card img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.hero-image-card:hover img {
  transform: scale(1.03);
}

.image-overlay-badge {
  position: absolute;
  bottom: 1rem;
  left: 1rem;
  background: rgba(15, 23, 42, 0.85);
  color: #fff;
  backdrop-filter: blur(8px);
  padding: 0.4rem 0.9rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
  margin-top: 2.5rem;
  padding-top: 1.75rem;
  border-top: 1px solid var(--border-color);
}

.stat-item h3 {
  font-size: 2rem;
  color: var(--primary);
  font-weight: 800;
}

.stat-item p {
  color: var(--text-muted);
  font-size: 0.9rem;
}

/* Feature & Concept Cards */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
}

.glass-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2rem;
  transition: var(--transition);
  position: relative;
  box-shadow: var(--card-shadow);
}

.glass-card:hover {
  transform: translateY(-4px);
  border-color: var(--primary);
  box-shadow: 0 10px 25px rgba(2, 132, 199, 0.12);
}

.card-icon {
  width: 52px;
  height: 52px;
  border-radius: var(--radius-sm);
  background: rgba(2, 132, 199, 0.1);
  border: 1px solid rgba(2, 132, 199, 0.2);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.4rem;
  color: var(--primary);
  margin-bottom: 1.5rem;
}

.card-title {
  font-size: 1.3rem;
  margin-bottom: 0.75rem;
  font-weight: 700;
  color: var(--text-main);
}

.card-text {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-bottom: 1.25rem;
  line-height: 1.6;
}

.card-tag {
  display: inline-block;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  background: rgba(2, 132, 199, 0.08);
  font-size: 0.8rem;
  color: var(--primary);
  font-weight: 600;
}

/* Image Visual Cards */
.visual-card {
  background: var(--bg-card);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  overflow: hidden;
  transition: var(--transition);
  box-shadow: var(--card-shadow);
}

.visual-card:hover {
  transform: translateY(-5px);
  border-color: var(--primary);
  box-shadow: 0 12px 30px rgba(2, 132, 199, 0.15);
}

.card-img-wrap {
  position: relative;
  width: 100%;
  height: 210px;
  overflow: hidden;
  background: #f1f5f9;
}

.visual-card-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.visual-card:hover .visual-card-img {
  transform: scale(1.06);
}

.img-tag-badge {
  position: absolute;
  top: 0.75rem;
  right: 0.75rem;
  background: var(--primary);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-full);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.visual-card-body {
  padding: 1.75rem;
}

/* Timeline */
.timeline-container {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
}

.timeline-container::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--primary), var(--secondary));
  transform: translateX(-50%);
}

.timeline-item {
  display: flex;
  justify-content: flex-end;
  padding-right: 3rem;
  position: relative;
  margin-bottom: 2.5rem;
  width: 50%;
}

.timeline-item:nth-child(even) {
  align-self: flex-end;
  justify-content: flex-start;
  padding-right: 0;
  padding-left: 3rem;
  margin-left: 50%;
}

.timeline-dot {
  position: absolute;
  right: -9px;
  top: 1.5rem;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--primary);
  z-index: 2;
  box-shadow: 0 0 0 4px #ffffff;
}

[data-theme="dark"] .timeline-dot {
  box-shadow: 0 0 0 4px #0f172a;
}

.timeline-item:nth-child(even) .timeline-dot {
  right: auto;
  left: -9px;
}

.timeline-content {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 1.75rem;
  border-radius: var(--radius-md);
  transition: var(--transition);
  box-shadow: var(--card-shadow);
}

.timeline-content:hover {
  border-color: var(--primary);
}

.timeline-year {
  display: inline-block;
  padding: 0.2rem 0.75rem;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: #fff;
  border-radius: var(--radius-full);
  font-weight: 700;
  font-size: 0.85rem;
  margin-bottom: 0.75rem;
}

/* Interactive Demos Tab Interface */
.demo-tabs {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.demo-tab-btn {
  background: #ffffff;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.03);
}

[data-theme="dark"] .demo-tab-btn {
  background: rgba(255, 255, 255, 0.05);
}

.demo-tab-btn.active, .demo-tab-btn:hover {
  color: var(--primary);
  background: #ffffff;
  border-color: var(--primary);
  box-shadow: 0 4px 12px rgba(2, 132, 199, 0.12);
}

.demo-panel {
  display: none;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--card-shadow);
}

.demo-panel.active {
  display: block;
  animation: fadeIn 0.4s ease;
}

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

/* Demo 1: Sentiment Classifier */
.sentiment-box {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.input-group {
  margin-bottom: 1.5rem;
}

.input-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

textarea, input[type="text"], select {
  width: 100%;
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1rem;
  color: var(--text-main);
  font-family: var(--font-main);
  font-size: 1rem;
  transition: var(--transition);
}

[data-theme="dark"] textarea, [data-theme="dark"] input[type="text"], [data-theme="dark"] select {
  background: rgba(15, 23, 42, 0.6);
}

textarea:focus, input[type="text"]:focus, select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.15);
}

.sample-btn {
  background: #f1f5f9;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition);
}

.sample-btn:hover {
  color: var(--primary);
  border-color: var(--primary);
  background: #e2e8f0;
}

.sentiment-result {
  background: #f8fafc;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
}

[data-theme="dark"] .sentiment-result {
  background: rgba(15, 23, 42, 0.4);
}

.sentiment-badge {
  font-size: 3rem;
  margin-bottom: 0.5rem;
}

.sentiment-label {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.confidence-bar-wrap {
  width: 100%;
  height: 10px;
  background: #e2e8f0;
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-top: 1rem;
}

[data-theme="dark"] .confidence-bar-wrap {
  background: rgba(255, 255, 255, 0.1);
}

.confidence-bar {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--primary), var(--success));
  transition: width 0.6s ease;
}

/* Demo 2: Neural Net Simulator */
.net-controls {
  display: flex;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
  align-items: center;
  flex-wrap: wrap;
}

.net-visualizer {
  height: 340px;
  width: 100%;
  background: #f1f5f9;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  position: relative;
  overflow: hidden;
}

[data-theme="dark"] .net-visualizer {
  background: rgba(15, 23, 42, 0.6);
}

/* Demo 3: Prompt Studio */
.prompt-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.prompt-output-box {
  background: #0f172a;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.9rem;
  color: #38bdf8;
  white-space: pre-wrap;
  min-height: 250px;
}

/* Demo 4: Computer Vision Simulator */
.cv-box {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: center;
}

.cv-viewport {
  position: relative;
  width: 100%;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.cv-viewport img {
  width: 100%;
  display: block;
}

.cv-bbox {
  position: absolute;
  border: 2px solid var(--primary);
  background: rgba(2, 132, 199, 0.15);
  transition: var(--transition);
  border-radius: 4px;
}

.cv-bbox-label {
  position: absolute;
  top: -24px;
  left: -2px;
  background: var(--primary);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 800;
  padding: 2px 6px;
  border-radius: 3px;
}

/* Quiz Section */
.quiz-container {
  max-width: 800px;
  margin: 0 auto;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--card-shadow);
}

.quiz-progress {
  display: flex;
  justify-content: space-between;
  margin-bottom: 1.5rem;
  color: var(--text-muted);
  font-weight: 600;
}

.quiz-progress-bar {
  height: 6px;
  background: #e2e8f0;
  border-radius: var(--radius-full);
  margin-bottom: 2rem;
  overflow: hidden;
}

.quiz-progress-fill {
  height: 100%;
  width: 20%;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  transition: width 0.3s ease;
}

.quiz-question {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: var(--text-main);
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 2rem;
}

.quiz-option-btn {
  background: #f8fafc;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.1rem 1.5rem;
  color: var(--text-main);
  font-family: var(--font-main);
  font-size: 1rem;
  text-align: left;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 1rem;
}

.quiz-option-btn:hover {
  background: #f1f5f9;
  border-color: var(--primary);
}

.quiz-option-btn.selected {
  border-color: var(--primary);
  background: rgba(2, 132, 199, 0.08);
}

.quiz-option-btn.correct {
  border-color: var(--success) !important;
  background: rgba(5, 150, 105, 0.1) !important;
}

.quiz-option-btn.wrong {
  border-color: var(--accent) !important;
  background: rgba(225, 29, 72, 0.1) !important;
}

.option-letter {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: #e2e8f0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--text-main);
}

.quiz-explanation {
  background: rgba(2, 132, 199, 0.08);
  border-left: 4px solid var(--primary);
  padding: 1.25rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: 1.5rem;
  display: none;
  color: var(--text-main);
}

/* Glossary Section */
.glossary-controls {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.glossary-search {
  flex: 1;
  min-width: 280px;
}

.glossary-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.5rem;
}

.glossary-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  transition: var(--transition);
  box-shadow: var(--card-shadow);
}

.glossary-card:hover {
  border-color: var(--primary);
  transform: translateY(-4px);
}

.glossary-term {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 0.25rem;
}

.glossary-en {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 0.75rem;
  font-style: italic;
}

.glossary-desc {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.55;
}

/* Footer */
footer {
  background: #f1f5f9;
  border-top: 1px solid var(--border-color);
  padding: 4rem 0 2rem 0;
  color: var(--text-muted);
}

[data-theme="dark"] footer {
  background: #0f172a;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 1rem;
}

.footer-links h4 {
  color: var(--text-main);
  font-size: 1.1rem;
  margin-bottom: 1.25rem;
}

.footer-links ul {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.65rem;
}

.footer-links a {
  color: var(--text-muted);
  text-decoration: none;
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--primary);
}

.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.9rem;
}

/* Responsive Styles */
@media (max-width: 992px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }
  
  .hero-actions {
    justify-content: center;
  }
  
  .hero-title {
    font-size: 2.7rem;
  }
  
  .sentiment-box, .prompt-grid, .cv-box {
    grid-template-columns: 1fr;
  }
  
  .timeline-item, .timeline-item:nth-child(even) {
    width: 100%;
    padding-left: 3rem;
    padding-right: 0;
    margin-left: 0;
  }
  
  .timeline-container::before {
    left: 1rem;
  }
  
  .timeline-dot, .timeline-item:nth-child(even) .timeline-dot {
    left: 0.4rem;
  }
  
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .mobile-toggle {
    display: block;
  }
  
  .hero-title {
    font-size: 2.1rem;
  }
  
  .section-title {
    font-size: 1.9rem;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
  }
}