/* ============================================================
   JuGeo — Judgment Geometry Documentation Site
   Design System & Global Styles
   ============================================================ */

/* --- CSS Variables / Design Tokens --- */
:root {
  /* Primary palette — deep mathematical blue to violet */
  --color-primary: #4f46e5;
  --color-primary-light: #818cf8;
  --color-primary-dark: #3730a3;
  --color-primary-50: #eef2ff;
  --color-primary-100: #e0e7ff;
  --color-primary-900: #312e81;

  /* Accent — geometric gold */
  --color-accent: #f59e0b;
  --color-accent-light: #fbbf24;
  --color-accent-dark: #d97706;

  /* Semantic colors */
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-danger: #ef4444;
  --color-info: #3b82f6;

  /* Trust level colors */
  --trust-verified: #059669;
  --trust-solver: #2563eb;
  --trust-runtime: #7c3aed;
  --trust-oracle: #db2777;
  --trust-copilot: #ea580c;
  --trust-unverified: #6b7280;
  --trust-contradicted: #dc2626;

  /* Neutrals */
  --color-bg: #0f0f23;
  --color-bg-alt: #161630;
  --color-bg-card: #1a1a3e;
  --color-bg-code: #12122a;
  --color-surface: #22224a;
  --color-border: #2d2d5e;
  --color-border-light: #3d3d7e;
  --color-text: #e2e8f0;
  --color-text-muted: #94a3b8;
  --color-text-dim: #64748b;
  --color-heading: #f8fafc;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
  --font-display: 'Space Grotesk', var(--font-sans);
  --font-math: 'KaTeX_Main', 'STIX Two Math', 'Latin Modern Math', serif;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 14px rgba(0,0,0,0.4);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.5);
  --shadow-glow: 0 0 30px rgba(79,70,229,0.15);
  --shadow-glow-accent: 0 0 30px rgba(245,158,11,0.1);

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);

  /* Layout */
  --max-width: 1280px;
  --max-width-narrow: 900px;
  --nav-height: 64px;
  --sidebar-width: 280px;
}

/* --- Light Mode --- */
[data-theme="light"] {
  --color-bg: #f8fafc;
  --color-bg-alt: #f1f5f9;
  --color-bg-card: #ffffff;
  --color-bg-code: #f1f5f9;
  --color-surface: #e2e8f0;
  --color-border: #cbd5e1;
  --color-border-light: #e2e8f0;
  --color-text: #1e293b;
  --color-text-muted: #475569;
  --color-text-dim: #64748b;
  --color-heading: #0f172a;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow-md: 0 4px 14px rgba(0,0,0,0.08);
  --shadow-lg: 0 10px 40px rgba(0,0,0,0.1);
  --shadow-glow: 0 0 30px rgba(79,70,229,0.08);
}

/* --- Reset & Base --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.7;
  overflow-x: hidden;
}

::selection {
  background: var(--color-primary);
  color: white;
}

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

h1 { font-size: clamp(2rem, 5vw, 3.5rem); font-weight: 700; }
h2 { font-size: clamp(1.5rem, 3vw, 2.25rem); font-weight: 600; margin-top: var(--space-3xl); }
h3 { font-size: clamp(1.25rem, 2vw, 1.5rem); font-weight: 600; margin-top: var(--space-2xl); }
h4 { font-size: 1.125rem; font-weight: 600; margin-top: var(--space-xl); }

p { margin: var(--space-md) 0; max-width: 72ch; }

a {
  color: var(--color-primary-light);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--color-accent-light); }

strong { color: var(--color-heading); font-weight: 600; }

code {
  font-family: var(--font-mono);
  font-size: 0.875em;
  background: var(--color-bg-code);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
}

pre {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.6;
  background: var(--color-bg-code);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  overflow-x: auto;
  position: relative;
}

pre code {
  background: none;
  border: none;
  padding: 0;
  font-size: inherit;
}

/* Syntax highlighting */
.token-keyword { color: #c792ea; }
.token-string { color: #c3e88d; }
.token-comment { color: #546e7a; font-style: italic; }
.token-function { color: #82aaff; }
.token-number { color: #f78c6c; }
.token-class { color: #ffcb6b; }
.token-decorator { color: #f07178; }
.token-operator { color: #89ddff; }
.token-type { color: #c792ea; }
.token-builtin { color: #82aaff; }

/* --- Layout --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.container-narrow {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(15, 15, 35, 0.85);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  transition: background var(--transition-base);
}

[data-theme="light"] .nav {
  background: rgba(248, 250, 252, 0.85);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
  display: flex;
  align-items: center;
  height: 100%;
  gap: var(--space-xl);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-heading);
  text-decoration: none;
}

.nav-logo .logo-icon {
  width: 32px;
  height: 32px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  color: white;
  font-weight: 800;
}

.nav-links {
  display: flex;
  gap: var(--space-xs);
  list-style: none;
}

.nav-links a {
  display: block;
  padding: var(--space-sm) var(--space-md);
  color: var(--color-text-muted);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-heading);
  background: var(--color-surface);
}

.nav-right {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.nav-search {
  display: flex;
  align-items: center;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 6px 12px;
  gap: var(--space-sm);
  cursor: pointer;
  transition: border-color var(--transition-fast);
}

.nav-search:hover { border-color: var(--color-primary-light); }
.nav-search input {
  background: none;
  border: none;
  outline: none;
  color: var(--color-text);
  font-size: 0.85rem;
  width: 160px;
  font-family: var(--font-sans);
}
.nav-search kbd {
  background: var(--color-bg);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.7rem;
  border: 1px solid var(--color-border);
  color: var(--color-text-dim);
}

.theme-toggle {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  cursor: pointer;
  padding: 6px 8px;
  font-size: 1rem;
  transition: all var(--transition-fast);
}
.theme-toggle:hover { color: var(--color-heading); border-color: var(--color-primary-light); }

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--color-text);
  font-size: 1.5rem;
  cursor: pointer;
}

/* --- Hero Section --- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: var(--nav-height);
}

.hero-bg {
  position: absolute;
  inset: 0;
  overflow: hidden;
  z-index: 0;
}

.hero-bg canvas {
  width: 100%;
  height: 100%;
}

.hero-gradient {
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 30% 50%, rgba(79,70,229,0.15) 0%, transparent 60%),
              radial-gradient(ellipse at 70% 30%, rgba(245,158,11,0.08) 0%, transparent 50%),
              radial-gradient(ellipse at 50% 80%, rgba(99,102,241,0.1) 0%, transparent 50%);
  z-index: 1;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-4xl) var(--space-xl);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  background: rgba(79,70,229,0.15);
  border: 1px solid rgba(79,70,229,0.3);
  color: var(--color-primary-light);
  padding: 6px 16px;
  border-radius: 100px;
  font-size: 0.85rem;
  font-weight: 500;
  margin-bottom: var(--space-xl);
  animation: fadeInUp 0.6s ease-out;
}

.hero-badge .pulse {
  width: 8px;
  height: 8px;
  background: var(--color-success);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  line-height: 1.1;
  max-width: 18ch;
  animation: fadeInUp 0.6s ease-out 0.1s both;
}

.hero h1 .gradient-text {
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-accent-light), var(--color-primary-light));
  background-size: 200% auto;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: gradientShift 4s ease-in-out infinite;
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  color: var(--color-text-muted);
  max-width: 60ch;
  margin-top: var(--space-lg);
  line-height: 1.6;
  animation: fadeInUp 0.6s ease-out 0.2s both;
}

.hero-actions {
  display: flex;
  gap: var(--space-md);
  margin-top: var(--space-2xl);
  flex-wrap: wrap;
  animation: fadeInUp 0.6s ease-out 0.3s both;
}

.hero-stats {
  display: flex;
  gap: var(--space-3xl);
  margin-top: var(--space-3xl);
  animation: fadeInUp 0.6s ease-out 0.4s both;
}

.hero-stat {
  display: flex;
  flex-direction: column;
}

.hero-stat-value {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-heading);
  line-height: 1;
}

.hero-stat-label {
  font-size: 0.85rem;
  color: var(--color-text-dim);
  margin-top: var(--space-xs);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition-base);
  text-decoration: none;
}

.btn-primary {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: white;
  box-shadow: 0 4px 14px rgba(79,70,229,0.4);
}
.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(79,70,229,0.5);
  color: white;
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-heading);
  border: 1px solid var(--color-border);
}
.btn-secondary:hover {
  background: var(--color-border);
  color: var(--color-heading);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
}
.btn-ghost:hover {
  color: var(--color-heading);
  border-color: var(--color-primary-light);
}

.btn-sm { padding: 8px 16px; font-size: 0.85rem; }
.btn-lg { padding: 16px 32px; font-size: 1.05rem; }
.btn-icon { padding: 8px; border-radius: var(--radius-sm); }

/* --- Cards --- */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  transition: all var(--transition-base);
}

.card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-lg);
}

.card-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  margin-bottom: var(--space-md);
}

.card h3 {
  margin-top: 0;
  font-size: 1.15rem;
}

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

/* Numbered cards for paper listing */
.card-numbered {
  position: relative;
  padding-left: calc(var(--space-xl) + 48px);
}

.card-number {
  position: absolute;
  left: var(--space-xl);
  top: var(--space-xl);
  width: 36px;
  height: 36px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 700;
  color: white;
}

/* --- Section styles --- */
.section {
  padding: var(--space-4xl) 0;
}

.section-label {
  text-transform: uppercase;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--color-primary-light);
  margin-bottom: var(--space-sm);
}

.section-header {
  max-width: 60ch;
  margin-bottom: var(--space-2xl);
}

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

/* --- Comparison Table --- */
.comparison-table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  font-size: 0.9rem;
}

.comparison-table th {
  background: var(--color-bg-card);
  padding: var(--space-md) var(--space-lg);
  text-align: left;
  font-weight: 600;
  color: var(--color-heading);
  border-bottom: 2px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.comparison-table td {
  padding: var(--space-md) var(--space-lg);
  border-bottom: 1px solid var(--color-border);
  vertical-align: top;
}

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

.comparison-table td:first-child {
  font-weight: 500;
  color: var(--color-heading);
  white-space: nowrap;
}

.comparison-table .check { color: var(--color-success); font-weight: 700; }
.comparison-table .cross { color: var(--color-text-dim); }
.comparison-table .star { color: var(--color-accent); font-weight: 700; }
.comparison-table .jugeo-col { background: rgba(79,70,229,0.05); }

/* --- Trust Level Badges --- */
.trust-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 10px;
  border-radius: 100px;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.trust-verified { background: rgba(5,150,105,0.15); color: var(--trust-verified); border: 1px solid rgba(5,150,105,0.3); }
.trust-solver { background: rgba(37,99,235,0.15); color: var(--trust-solver); border: 1px solid rgba(37,99,235,0.3); }
.trust-runtime { background: rgba(124,58,237,0.15); color: var(--trust-runtime); border: 1px solid rgba(124,58,237,0.3); }
.trust-oracle { background: rgba(219,39,119,0.15); color: var(--trust-oracle); border: 1px solid rgba(219,39,119,0.3); }
.trust-copilot { background: rgba(234,88,12,0.15); color: var(--trust-copilot); border: 1px solid rgba(234,88,12,0.3); }

/* --- Diagram / Architecture --- */
.arch-diagram {
  background: var(--color-bg-code);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-2xl);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  line-height: 1.8;
  color: var(--color-text-muted);
}

/* --- Tabs --- */
.tabs {
  display: flex;
  gap: 2px;
  background: var(--color-surface);
  border-radius: var(--radius-md);
  padding: 3px;
  margin-bottom: var(--space-lg);
  overflow-x: auto;
}

.tab-btn {
  flex: 1;
  padding: 10px 16px;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.tab-btn:hover { color: var(--color-heading); }
.tab-btn.active {
  background: var(--color-bg-card);
  color: var(--color-heading);
  box-shadow: var(--shadow-sm);
}

.tab-panel { display: none; }
.tab-panel.active { display: block; animation: fadeIn 0.3s ease-out; }

/* --- Code blocks with language label --- */
.code-block {
  position: relative;
  margin: var(--space-lg) 0;
}

.code-block .code-lang {
  position: absolute;
  top: 0;
  right: 0;
  background: var(--color-primary);
  color: white;
  padding: 3px 12px;
  border-radius: 0 var(--radius-md) 0 var(--radius-sm);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.code-block .copy-btn {
  position: absolute;
  top: 8px;
  right: 80px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-text-dim);
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  font-size: 0.7rem;
  cursor: pointer;
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.code-block:hover .copy-btn { opacity: 1; }
.code-block .copy-btn:hover { color: var(--color-heading); border-color: var(--color-primary-light); }

/* --- Sidebar (for docs pages) --- */
.docs-layout {
  display: flex;
  padding-top: var(--nav-height);
  min-height: 100vh;
}

.sidebar {
  width: var(--sidebar-width);
  position: fixed;
  top: var(--nav-height);
  left: 0;
  bottom: 0;
  background: var(--color-bg-alt);
  border-right: 1px solid var(--color-border);
  overflow-y: auto;
  padding: var(--space-lg) 0;
  z-index: 100;
  transition: transform var(--transition-base);
}

.sidebar-section {
  padding: 0 var(--space-lg);
  margin-bottom: var(--space-lg);
}

.sidebar-section-title {
  text-transform: uppercase;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--color-text-dim);
  padding: var(--space-sm) 0;
}

.sidebar-link {
  display: block;
  padding: 6px var(--space-md);
  color: var(--color-text-muted);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.sidebar-link:hover { color: var(--color-heading); background: var(--color-surface); }
.sidebar-link.active {
  color: var(--color-primary-light);
  background: rgba(79,70,229,0.1);
  font-weight: 500;
}

.docs-content {
  flex: 1;
  margin-left: var(--sidebar-width);
  padding: var(--space-2xl) var(--space-3xl);
  max-width: calc(100% - var(--sidebar-width));
}

/* --- MathJax overrides --- */
.MathJax { font-size: 1em !important; }
mjx-container { overflow-x: auto; }

/* --- Feature grid --- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.feature-item {
  padding: var(--space-xl);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
}

.feature-item:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-glow);
}

.feature-icon {
  font-size: 2rem;
  margin-bottom: var(--space-md);
}

/* --- Timeline for paper reading order --- */
.timeline {
  position: relative;
  padding-left: 32px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 12px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--color-primary), var(--color-accent), var(--color-primary-dark));
}

.timeline-item {
  position: relative;
  padding-bottom: var(--space-xl);
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -26px;
  top: 6px;
  width: 12px;
  height: 12px;
  background: var(--color-primary);
  border-radius: 50%;
  border: 3px solid var(--color-bg);
}

/* --- Footer --- */
.footer {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  padding: var(--space-3xl) 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-2xl);
}

.footer-brand p {
  color: var(--color-text-dim);
  font-size: 0.9rem;
}

.footer-section h4 {
  color: var(--color-heading);
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-md);
  margin-top: 0;
}

.footer-section a {
  display: block;
  color: var(--color-text-dim);
  font-size: 0.85rem;
  padding: 4px 0;
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--color-text-dim);
}

/* --- Animations --- */
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.5); }
}

@keyframes gradientShift {
  0%, 100% { background-position: 0% center; }
  50% { background-position: 200% center; }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

/* Scroll-triggered animations */
.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.animate-on-scroll.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children */
.stagger-children > * {
  opacity: 0;
  transform: translateY(20px);
  transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.stagger-children.visible > *:nth-child(1) { transition-delay: 0ms; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(2) { transition-delay: 80ms; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(3) { transition-delay: 160ms; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(4) { transition-delay: 240ms; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(5) { transition-delay: 320ms; opacity: 1; transform: translateY(0); }
.stagger-children.visible > *:nth-child(6) { transition-delay: 400ms; opacity: 1; transform: translateY(0); }

/* --- TOC (table of contents, right rail) --- */
.toc {
  position: fixed;
  right: var(--space-xl);
  top: calc(var(--nav-height) + var(--space-2xl));
  width: 220px;
  font-size: 0.8rem;
}

.toc-title {
  text-transform: uppercase;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--color-text-dim);
  margin-bottom: var(--space-sm);
}

.toc a {
  display: block;
  padding: 4px 0 4px 12px;
  color: var(--color-text-dim);
  border-left: 2px solid transparent;
  transition: all var(--transition-fast);
}

.toc a:hover,
.toc a.active {
  color: var(--color-primary-light);
  border-left-color: var(--color-primary-light);
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, 1fr); }
  .hero-stats { gap: var(--space-xl); }
  .toc { display: none; }
  .comparison-table { font-size: 0.8rem; }
  .comparison-table td, .comparison-table th { padding: var(--space-sm) var(--space-md); }
}

@media (max-width: 768px) {
  .nav-links { display: none; }
  .nav-toggle { display: block; }
  .nav-search { display: none; }

  .hero h1 { font-size: 2.2rem; }
  .hero-stats { flex-direction: column; gap: var(--space-lg); }
  .hero-actions { flex-direction: column; }
  .hero-actions .btn { width: 100%; justify-content: center; }

  .feature-grid { grid-template-columns: 1fr; }
  .card-grid { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }

  .sidebar { transform: translateX(-100%); }
  .sidebar.open { transform: translateX(0); }
  .docs-content { margin-left: 0; padding: var(--space-lg); }

  .comparison-table { display: block; overflow-x: auto; }
}

/* --- Scrollbar --- */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: var(--color-bg); }
::-webkit-scrollbar-thumb {
  background: var(--color-border);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover { background: var(--color-border-light); }

/* --- Math display blocks --- */
.math-display {
  background: var(--color-bg-code);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-lg) var(--space-xl);
  margin: var(--space-lg) 0;
  overflow-x: auto;
  text-align: center;
}

.math-inline {
  padding: 0 2px;
}

/* --- Callout boxes --- */
.callout {
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin: var(--space-lg) 0;
  border-left: 4px solid;
}

.callout-info { background: rgba(59,130,246,0.08); border-color: var(--color-info); }
.callout-warning { background: rgba(245,158,11,0.08); border-color: var(--color-warning); }
.callout-success { background: rgba(16,185,129,0.08); border-color: var(--color-success); }
.callout-danger { background: rgba(239,68,68,0.08); border-color: var(--color-danger); }

.callout-title {
  font-weight: 600;
  margin-bottom: var(--space-sm);
  color: var(--color-heading);
}

/* --- Interactive demo area --- */
.demo-area {
  background: var(--color-bg-code);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.demo-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}

.demo-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}
.demo-dot-red { background: #ff5f57; }
.demo-dot-yellow { background: #febc2e; }
.demo-dot-green { background: #28c840; }

.demo-body {
  padding: var(--space-lg);
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.7;
  min-height: 200px;
}

.demo-prompt {
  color: var(--color-success);
}
.demo-command {
  color: var(--color-heading);
}
.demo-output {
  color: var(--color-text-muted);
}

/* --- Badge styles for paper tags --- */
.tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 100px;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

.tag-theory { background: rgba(79,70,229,0.15); color: var(--color-primary-light); }
.tag-implementation { background: rgba(16,185,129,0.15); color: var(--color-success); }
.tag-empirical { background: rgba(245,158,11,0.15); color: var(--color-accent); }
.tag-copilot { background: rgba(219,39,119,0.15); color: var(--trust-oracle); }
.tag-lean { background: rgba(124,58,237,0.15); color: var(--trust-runtime); }

/* --- Diagram containers --- */
.diagram-container {
  margin: var(--space-xl) 0;
  text-align: center;
}

.diagram-container svg {
  max-width: 100%;
  height: auto;
}

/* --- Paper listing (3-col) --- */
.paper-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--space-lg);
}

.paper-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: all var(--transition-base);
  display: flex;
  flex-direction: column;
}

.paper-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-glow);
  transform: translateY(-2px);
}

.paper-card-num {
  font-family: var(--font-display);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--color-primary-light);
  margin-bottom: var(--space-sm);
}

.paper-card h3 {
  font-size: 1rem;
  margin-top: 0;
  margin-bottom: var(--space-sm);
}

.paper-card p {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  flex: 1;
}

.paper-card-footer {
  display: flex;
  gap: var(--space-sm);
  margin-top: var(--space-md);
  flex-wrap: wrap;
}

/* --- Page transition --- */
.page-enter {
  animation: fadeInUp 0.4s ease-out;
}