/* ─── Design Tokens ─────────────────────────────────────────── */
:root {
  /* Page backgrounds */
  --color-page-bg: #0b0e17;
  --color-page-bg-alt: #090c14;
  --color-hero-gradient: linear-gradient(135deg, #0b0e17 0%, #162038 40%, #1a1a40 70%, #0d1225 100%);
  --color-section-alt: linear-gradient(180deg, #0b0e17 0%, #10152a 50%, #0b0e17 100%);

  /* Panel backgrounds */
  --color-panel-bg: #161b30;
  --color-panel-bg-alt: #11142a;
  --color-surface-bg: #131830;
  --color-surface-bg-alt: #1a1f38;
  --color-card-bg: linear-gradient(160deg, #181d30, #13172a);
  --color-card-bg-active: linear-gradient(160deg, #1e2540, #15203a);

  /* Borders */
  --color-border: rgba(99, 160, 255, 0.15);
  --color-border-strong: rgba(99, 160, 255, 0.1);
  --color-border-muted: rgba(99, 160, 255, 0.08);
  --color-border-input: #2a3055;
  --color-border-input-hover: #3a4270;

  /* Text */
  --color-text-primary: #e4e8f0;
  --color-text-secondary: #b8c2d8;
  --color-text-tertiary: #a8b4cc;
  --color-text-muted: #8a9cc7;
  --color-text-subtle: #7d8cae;
  --color-text-dim: #6e7da6;
  --color-text-disabled: #5d6a8a;
  --color-text-heading: #ffffff;

  /* Accents */
  --color-accent-blue: #4f7df9;
  --color-accent-violet: #7c5ce0;
  --color-accent-cyan: #7fb3ff;
  --color-accent-teal: #38b5a0;
  --color-accent-pink: #e76af0;

  /* Generation accents */
  --color-gen-1: #4f7df9;
  --color-gen-2: #38b5a0;
  --color-gen-3: #e76af0;
  --color-gen-4: #ffab40;

  /* States */
  --color-success: #9be8c8;
  --color-success-bg: rgba(56, 181, 160, 0.16);
  --color-success-border: rgba(155, 232, 200, 0.45);
  --color-warning: #ffd166;
  --color-warning-bg: rgba(255, 209, 102, 0.16);
  --color-warning-border: rgba(255, 209, 102, 0.45);

  /* Focus */
  --color-focus-ring: #a78bfa;
  --focus-ring-width: 3px;

  /* Spacing scale (base = 1rem) */
  --space-3xs: 0.25rem;
  --space-2xs: 0.5rem;
  --space-xs: 0.75rem;
  --space-sm: 1rem;
  --space-md: 1.25rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 2.5rem;
  --space-3xl: 3rem;
  --space-4xl: 4rem;

  /* Border radii */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 10px;
  --radius-xl: 12px;
  --radius-2xl: 14px;
  --radius-3xl: 16px;
  --radius-full: 999px;
  --radius-card: var(--radius-2xl);
  --radius-panel: var(--radius-3xl);

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 24px rgba(79, 125, 249, 0.12);
  --shadow-lg: 0 6px 28px rgba(79, 125, 249, 0.15);
  --shadow-xl: 0 8px 32px rgba(79, 125, 249, 0.18);
  --shadow-focus: 0 0 0 var(--focus-ring-width) rgba(167, 139, 250, 0.5);

  /* Transition durations */
  --duration-fast: 120ms;
  --duration-base: 200ms;
  --duration-slow: 300ms;
  --ease-standard: ease;
  --ease-emphasized: cubic-bezier(0.2, 0, 0, 1);

  /* Content widths */
  --max-content-width: 1100px;
  --max-text-width: 640px;
  --max-readable-width: 68ch;

  /* Touch targets */
  --touch-target-min: 44px;

  /* Grid */
  --grid-gutter: 1.25rem;
}

@media (prefers-reduced-motion: reduce) {
  :root {
    --duration-fast: 0.01ms;
    --duration-base: 0.01ms;
    --duration-slow: 0.01ms;
  }
}

/* ─── Reset & Base ──────────────────────────────────────────── */
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; }

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

html {
  scroll-behavior: smooth;
  overflow-x: hidden;
  font-size: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  line-height: 1.6;
  color: var(--color-text-primary);
  background: var(--color-page-bg);
  min-width: 320px;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ─── Skip Link ─────────────────────────────────────────────── */
.skip-link {
  position: fixed;
  top: -50px;
  left: -9999px;
  z-index: 100;
  padding: var(--space-xs) var(--space-md);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-heading);
  background: var(--color-accent-blue);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: left var(--duration-fast) var(--ease-standard), top var(--duration-fast) var(--ease-standard);
}

.skip-link:focus {
  top: var(--space-sm);
  left: var(--space-sm);
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 2px;
}

/* ─── Screen reader only ────────────────────────────────────── */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ─── Container ─────────────────────────────────────────────── */
.container {
  width: 100%;
  max-width: var(--max-content-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
}

/* ═══════════════ Hero ═══════════════ */
.hero {
  position: relative;
  min-height: 40vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: var(--color-hero-gradient);
  overflow: hidden;
  padding: var(--space-4xl) var(--space-md);
}

.hero-bg-shapes {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(99, 160, 255, .04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(99, 160, 255, .04) 1px, transparent 1px);
  background-size: 48px 48px;
}

.hero h1 {
  font-size: clamp(2.4rem, 6vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--color-text-heading);
  margin-bottom: var(--space-2xs);
}

.hero-subtitle {
  font-size: clamp(1rem, 2.5vw, 1.35rem);
  color: var(--color-text-muted);
  margin-bottom: var(--space-lg);
  letter-spacing: .04em;
  text-transform: uppercase;
}

.hero-desc {
  max-width: var(--max-text-width);
  margin: 0 auto var(--space-3xl);
  font-size: clamp(.95rem, 1.8vw, 1.1rem);
  color: var(--color-text-tertiary);
  line-height: 1.65;
}

.cta-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2xs);
  min-height: var(--touch-target-min);
  padding: var(--space-sm) var(--space-2xl);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-text-heading);
  background: linear-gradient(135deg, var(--color-accent-blue), var(--color-accent-violet));
  border-radius: var(--radius-md);
  text-decoration: none;
  cursor: pointer;
  transition: transform var(--duration-base) var(--ease-standard), box-shadow var(--duration-base) var(--ease-standard);
  box-shadow: var(--shadow-md);
  border: none;
}

.cta-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 32px rgba(79, 125, 249, .45);
}

.cta-btn:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 3px;
  box-shadow: var(--shadow-focus);
}

/* ─── Section Titles ────────────────────────────────────────── */
.timeline-section, .matchup-section {
  padding: var(--space-4xl) 0;
}

.matchup-section {
  background: var(--color-section-alt);
}

.timeline-section > .container > h2,
.matchup-section h2,
.milestones-section > .container > h2 {
  text-align: center;
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  color: var(--color-text-heading);
  margin-bottom: var(--space-2xs);
}

.section-intro {
  max-width: var(--max-text-width);
  margin: 0 auto var(--space-3xl);
  font-size: clamp(.92rem, 1.8vw, 1.05rem);
  color: var(--color-text-subtle);
  text-align: center;
  line-height: 1.65;
}

/* ─── Timeline / Gen Cards ──────────────────────────────────── */
.generation-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-md);
  margin-top: var(--space-sm);
}

/* ─── Individual Generation Card ───────────────────────────── */
.gen-card {
  position: relative;
  background: var(--color-card-bg);
  border: 2px solid transparent;
  border-radius: var(--radius-card);
  padding: var(--space-lg) var(--space-md);
  cursor: pointer;
  transition:
    border-color var(--duration-base) var(--ease-standard),
    box-shadow var(--duration-base) var(--ease-standard),
    background var(--duration-base) var(--ease-standard);
  text-align: left;
  font-family: inherit;
  color: var(--color-text-primary);
  min-height: var(--touch-target-min);
}

.gen-card:hover {
  border-color: rgba(99, 160, 255, .35);
  box-shadow: var(--shadow-md);
}

.gen-card:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 3px;
}

.gen-card.active {
  border-color: var(--color-accent-blue);
  background: var(--color-card-bg-active);
  box-shadow: var(--shadow-lg);
}

.gen-card.active::after {
  content: '\2713\00a0Selected';
  position: absolute;
  top: var(--space-xs);
  right: var(--space-sm);
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--color-success);
  background: var(--color-success-bg);
  border: 1px solid var(--color-success-border);
  border-radius: var(--radius-full);
  padding: .18rem .55rem;
}

.gen-card::before {
  content: '';
  position: absolute;
  top: 0; bottom: 0; left: 0;
  width: 4px;
  border-radius: var(--radius-card) 0 0 var(--radius-card);
  background: var(--color-accent-blue);
}

.gen-card[data-index="0"]::before { background: var(--color-gen-1); }
.gen-card[data-index="1"]::before { background: var(--color-gen-2); }
.gen-card[data-index="2"]::before { background: var(--color-gen-3); }
.gen-card[data-index="3"]::before { background: var(--color-gen-4); }

/* ─── Card internal content ─────────────────────────────────── */
.gen-card .card-era {
  display: inline-block;
  font-size: .78rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--color-text-dim);
  margin-bottom: var(--space-2xs);
}

.gen-card h3 {
  font-size: 1.05rem;
  line-height: 1.35;
  margin-bottom: var(--space-2xs);
  color: var(--color-text-heading);
}

.gen-card p {
  font-size: .92rem;
  color: var(--color-text-muted);
}

/* ─── Detail Panel ──────────────────────────────────────────── */
.detail-panel {
  display: none;
  margin-top: var(--space-3xl);
  background: var(--color-panel-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-panel);
  padding: var(--space-2xl) var(--space-xl);
  transition: opacity var(--duration-base) var(--ease-standard);
}

.detail-panel.visible {
  display: block;
  opacity: 1;
}

.detail-header {
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--color-border-strong);
}

.detail-era-badge {
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--color-accent-blue);
  margin-right: var(--space-2xs);
  display: inline-block;
}

.detail-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.detail-block h3 {
  font-size: .95rem;
  color: var(--color-text-subtle);
  margin-bottom: var(--space-2xs);
  display: flex;
  align-items: center;
  gap: var(--space-2xs);
}

.detail-block p {
  font-size: .95rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.detail-title {
  display: inline-block;
  font-size: clamp(1.3rem, 3.2vw, 1.7rem);
  font-weight: 700;
  color: var(--color-text-heading);
  letter-spacing: .01em;
}

.detail-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  line-height: 26px;
  text-align: center;
  border-radius: var(--radius-sm);
  background: rgba(99, 160, 255, .14);
  color: var(--color-accent-cyan);
  font-size: .85rem;
  margin-right: var(--space-2xs);
  flex-shrink: 0;
}

/* ─── Landmark Human–AI Matches ─────────────────────────────── */
.milestones-section {
  padding: var(--space-4xl) 0;
}

.milestones-section > .container > h2 {
  text-align: center;
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  color: var(--color-text-heading);
  margin-bottom: var(--space-2xs);
}

.milestones-section .section-intro {
  max-width: var(--max-text-width);
  margin: 0 auto var(--space-3xl);
  font-size: clamp(.92rem, 1.8vw, 1.05rem);
  color: var(--color-text-subtle);
  text-align: center;
  line-height: 1.65;
}

.milestones-timeline {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-xl);
}

.milestone-control {
  position: relative;
  background: var(--color-card-bg);
  border: 2px solid transparent;
  border-radius: var(--radius-xl);
  padding: var(--space-md) var(--space-lg);
  cursor: pointer;
  transition:
    border-color var(--duration-base) var(--ease-standard),
    box-shadow var(--duration-base) var(--ease-standard),
    background var(--duration-base) var(--ease-standard);
  text-align: left;
  font-family: inherit;
  color: var(--color-text-primary);
  flex: 1 1 280px;
  min-height: var(--touch-target-min);
}

.milestone-control:hover {
  border-color: rgba(99, 160, 255, .35);
  box-shadow: var(--shadow-md);
}

.milestone-control:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 3px;
}

.milestone-control.active {
  border-color: var(--color-accent-blue);
  background: var(--color-card-bg-active);
  box-shadow: var(--shadow-lg);
}

.milestone-control.active::after {
  content: '\2713\00a0Selected';
  position: absolute;
  top: var(--space-2xs);
  right: var(--space-sm);
  font-size: .68rem;
  font-weight: 600;
  letter-spacing: .04em;
  color: var(--color-success);
  background: var(--color-success-bg);
  border: 1px solid var(--color-success-border);
  border-radius: var(--radius-full);
  padding: .15rem .5rem;
}

.milestone-control-year {
  display: inline-block;
  font-size: .85rem;
  font-weight: 700;
  color: var(--color-accent-blue);
  margin-bottom: var(--space-2xs);
}

.milestone-control-title {
  display: block;
  font-size: .95rem;
  line-height: 1.3;
  color: var(--color-text-heading);
}

/* ─── Milestone Detail Panel ────────────────────────────────── */
.milestone-panel {
  background: var(--color-panel-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-panel);
  padding: var(--space-2xl) var(--space-xl);
}

.milestone-panel.hidden { display: none !important; }

.milestone-header {
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--color-border-strong);
}

.milestone-year {
  font-size: .85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--color-accent-blue);
  display: inline-block;
  margin-bottom: var(--space-2xs);
}

.milestone-title {
  font-size: clamp(1.3rem, 3.2vw, 1.7rem);
  font-weight: 700;
  color: var(--color-text-heading);
  letter-spacing: .01em;
}

.milestone-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.milestone-dl {
  grid-column: 1 / -1;
}

.milestone-dl dt {
  font-size: .85rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--color-text-subtle);
  margin-bottom: var(--space-2xs);
}

.milestone-dl dd {
  font-size: .93rem;
  line-height: 1.55;
  color: var(--color-text-secondary);
  margin: 0 0 var(--space-md) 0;
}

.milestone-sources {
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border-strong);
}

.milestone-sources h4 {
  font-size: .85rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--color-text-subtle);
  margin-bottom: var(--space-sm);
}

.milestone-sources .source-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.milestone-sources .source-list li {
  margin-bottom: var(--space-2xs);
}

.milestone-sources .source-list a {
  color: var(--color-accent-cyan);
  text-decoration: underline;
  text-underline-offset: 2px;
  font-size: .9rem;
  word-break: break-word;
  display: inline-block;
  max-width: 100%;
}

.milestone-sources .source-list a:hover {
  color: #a7c9ff;
}

.milestone-sources .source-list a:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* ─── Milestone Comparison ──────────────────────────────────── */
.milestone-compare-trigger {
  margin: var(--space-xl) 0;
  text-align: center;
}

.compare-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: var(--touch-target-min);
  padding: var(--space-sm) var(--space-2xl);
  font-size: .95rem;
  font-weight: 600;
  color: var(--color-text-heading);
  background: linear-gradient(135deg, var(--color-accent-blue), var(--color-accent-violet));
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: transform var(--duration-base) var(--ease-standard), box-shadow var(--duration-base) var(--ease-standard);
  box-shadow: 0 3px 16px rgba(79, 125, 249, .25);
}

.compare-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 5px 24px rgba(79, 125, 249, .4);
}

.compare-btn:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 3px;
  box-shadow: var(--shadow-focus);
}

.milestone-compare {
  margin: var(--space-xl) 0;
  background: var(--color-panel-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-panel);
  padding: var(--space-2xl) var(--space-xl);
  transition: opacity var(--duration-base) var(--ease-standard);
}

.milestone-compare.hidden {
  display: none !important;
}

.milestone-compare-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.milestone-compare-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-md);
  border-bottom: 1px solid var(--color-border-strong);
  padding-bottom: var(--space-md);
}

.milestone-compare-title {
  font-size: clamp(1.3rem, 3vw, 1.6rem);
  font-weight: 700;
  color: var(--color-text-heading);
  margin: 0;
}

.milestone-compare-controls {
  display: flex;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.swap-btn,
.close-compare-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: var(--touch-target-min);
  padding: var(--space-sm) var(--space-lg);
  font-size: .9rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: transform var(--duration-base) var(--ease-standard), box-shadow var(--duration-base) var(--ease-standard);
}

.swap-btn {
  color: var(--color-text-heading);
  background: linear-gradient(135deg, var(--color-accent-teal), var(--color-accent-blue));
  box-shadow: 0 3px 16px rgba(56, 181, 160, .25);
}

.swap-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 5px 24px rgba(56, 181, 160, .35);
}

.close-compare-btn {
  color: var(--color-text-muted);
  background: transparent;
  border: 2px solid var(--color-border-input);
}

.close-compare-btn:hover {
  border-color: var(--color-accent-blue);
  color: var(--color-text-secondary);
}

.swap-btn:focus-visible,
.close-compare-btn:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 3px;
  box-shadow: var(--shadow-focus);
}

.milestone-compare-selectors {
  display: flex;
  gap: var(--space-lg);
  flex-wrap: wrap;
}

.milestone-compare-selectors .form-group {
  flex: 1 1 200px;
  min-width: 200px;
}

.milestone-compare-selectors .form-group label {
  font-size: .84rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--color-text-subtle);
  margin-bottom: var(--space-2xs);
  cursor: pointer;
}

.milestone-compare-selectors select {
  width: 100%;
  padding: var(--space-sm) var(--space-lg);
  font-size: .95rem;
  font-family: inherit;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-input);
  background: var(--color-surface-bg-alt);
  color: var(--color-text-primary);
  appearance: none;
  -webkit-appearance: none;
  cursor: pointer;
}

.milestone-compare-selectors select:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 2px;
  border-color: var(--color-accent-cyan);
}

.milestone-compare-selectors select:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.milestone-compare-selectors select:disabled option {
  color: var(--color-text-dim);
}

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

.milestone-compare-column {
  background: var(--color-surface-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
}

.milestone-compare-column-inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.milestone-compare-col-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--color-accent-cyan);
  margin: 0;
}

.milestone-compare-field {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-2xs);
}

.milestone-compare-field-label {
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--color-text-subtle);
}

.milestone-compare-field-value {
  font-size: .93rem;
  line-height: 1.55;
  color: var(--color-text-secondary);
  word-break: break-word;
}

/* At-a-glance summary */
.compare-at-a-glance {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: var(--space-md);
  margin-top: var(--space-lg);
  padding: var(--space-md);
  background: var(--color-surface-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.compare-at-a-glance-item {
  display: flex;
  flex-direction: column;
  gap: var(--space-2xs);
}

.compare-at-a-glance-label {
  font-size: .78rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--color-text-subtle);
}

.compare-at-a-glance-value {
  font-size: .95rem;
  font-weight: 600;
  color: var(--color-text-primary);
  line-height: 1.4;
}

.compare-at-a-glance-value a {
  color: var(--color-accent-cyan);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.compare-at-a-glance-value a:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* View in detail action */
.compare-view-detail {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2xs);
  min-height: var(--touch-target-min);
  margin-top: var(--space-sm);
  padding: var(--space-2xs) var(--space-md);
  font-size: .85rem;
  font-weight: 600;
  color: var(--color-accent-cyan);
  background: rgba(127, 179, 255, .1);
  border: 1px solid rgba(127, 179, 255, .3);
  border-radius: var(--radius-md);
  text-decoration: none;
  cursor: pointer;
  transition: background var(--duration-base) var(--ease-standard), color var(--duration-base) var(--ease-standard);
}

.compare-view-detail:hover {
  background: rgba(127, 179, 255, .18);
  color: #a7c9ff;
}

.compare-view-detail:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 2px;
  box-shadow: var(--shadow-focus);
}

/* ─── Matchup Lab ───────────────────────────────────────────── */
.matchup-form {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  align-items: flex-end;
  background: var(--color-surface-bg);
  padding: var(--space-2xl);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);}

.form-group {
  display: flex;
  flex-direction: column;
  min-width: 180px;
  flex: 1;
}

.form-group label {
  font-size: .84rem;
  text-transform: uppercase;
  letter-spacing: .06em;
  color: var(--color-text-subtle);
  margin-bottom: var(--space-2xs);
  cursor: pointer;
}

.form-group select {
  width: 100%;
  max-width: 100%;
  min-width: 0;
  padding: var(--space-sm) var(--space-lg);
  font-size: .95rem;
  font-family: inherit;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-input);
  background: var(--color-surface-bg-alt);
  color: var(--color-text-primary);
  appearance: none;
  -webkit-appearance: none;
  cursor: pointer;
  min-height: var(--touch-target-min);
}

.form-group select:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 2px;
  border-color: var(--color-accent-cyan);
}

.form-group select:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.form-group .error-message {
  margin-top: var(--space-2xs);
  font-size: .82rem;
  color: var(--color-warning);
  display: flex;
  align-items: center;
  gap: var(--space-2xs);
}

.form-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  align-items: center;
}

.run-btn, .reset-btn {
  max-width: 100%;
  min-width: 0;
  font-size: .95rem;
  padding: var(--space-sm) var(--space-lg);
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  font-weight: 600;
  min-height: var(--touch-target-min);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--duration-base) var(--ease-standard), box-shadow var(--duration-base) var(--ease-standard);
}

.run-btn {
  color: var(--color-text-heading);
  background: linear-gradient(135deg, var(--color-accent-blue), var(--color-accent-violet));
  box-shadow: 0 3px 16px rgba(79, 125, 249, .25);
}

.run-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 5px 24px rgba(79, 125, 249, .4);
}

.run-btn:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 3px;
  box-shadow: var(--shadow-focus);
}

.run-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
  box-shadow: var(--shadow-sm);
  background: var(--color-surface-bg-alt);
  color: var(--color-text-muted);
}

.reset-btn {
  color: var(--color-text-muted);
  background: transparent;
  border: 2px solid var(--color-border-input);
}

.reset-btn:hover {
  border-color: var(--color-accent-blue);
  color: var(--color-text-secondary);
}

.reset-btn:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 3px;
  box-shadow: var(--shadow-focus);
}

/* Results */
.matchup-result {
  margin-top: var(--space-xl);
  background: var(--color-panel-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl) var(--space-xl);
  transition: opacity var(--duration-base) var(--ease-standard);
}

.matchup-result.hidden { display: none !important; }

.matchup-result h2 {
  font-size: 1.4rem;
  color: var(--color-text-heading);
  margin-bottom: var(--space-xl);
}

.score-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--space-sm);
  flex-wrap: wrap;
}

.score-card {
  position: relative;
  text-align: center;
  padding: var(--space-xl) var(--space-2xl);
  border-radius: var(--radius-xl);
  min-width: 140px;
  background: var(--color-surface-bg);
  border: 1px solid var(--color-border);
}

.score-label {
  display: block;
  font-size: .8rem;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--color-text-subtle);
  margin-bottom: var(--space-2xs);
}

.score-value {
  display: block;
  font-size: 2.4rem;
  font-weight: 800;
  line-height: 1.15;
}

.score-human { color: var(--color-accent-blue); }
.score-ai    { color: var(--color-accent-pink); }

.vs-bubble {
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: #1c2145;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: .85rem;
  color: var(--color-text-dim);
}

.winner-line {
  text-align: center;
  margin: var(--space-lg) 0 var(--space-2xs);
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--color-text-tertiary);
}

.winner-line.ai-wins { color: var(--color-accent-pink); }
.winner-line.human-wins { color: var(--color-accent-blue); }
.winner-line.draw { color: var(--color-warning); }

.explanation-box {
  background: #111630;
  border-radius: var(--radius-lg);
  padding: var(--space-md) var(--space-xl);
  margin-top: var(--space-md);
}

.explanation-box h3 {
  font-size: .9rem;
  color: var(--color-text-subtle);
  margin-bottom: var(--space-2xs);
}

.explanation-box p {
  font-size: .93rem;
  line-height: 1.55;
  color: var(--color-text-secondary);
}

/* Score meters for matchup results */
.matchup-score-meter {
  display: block;
  width: 100%;
  height: 10px;
  border-radius: var(--radius-sm);
  background: rgba(99, 160, 255, .12);
  overflow: hidden;
  margin-top: var(--space-2xs);
}

.matchup-score-fill {
  display: block;
  height: 100%;
  border-radius: var(--radius-sm);
  transition: width var(--duration-slow) var(--ease-standard);
}

.matchup-score-fill.human {
  background: linear-gradient(90deg, var(--color-accent-blue), var(--color-accent-cyan));
}

.matchup-score-fill.ai {
  background: linear-gradient(90deg, var(--color-accent-pink), var(--color-accent-violet));
}

/* ─── Matchup Result Stage ──────────────────────────────────── */
.matchup-stage {
  margin-top: var(--space-xl);
  background: var(--color-panel-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl) var(--space-xl);
}

.matchup-stage.hidden { display: none !important; }

.matchup-stage-title {
  font-size: 1.4rem;
  color: var(--color-text-heading);
  margin-bottom: var(--space-xl);
  text-align: center;
}

/* Matchup Header */
.matchup-header {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-2xl);
  text-align: center;
}

.matchup-header-cell {
  display: flex;
  flex-direction: column;
  gap: var(--space-2xs);
}

.matchup-header-label {
  font-size: .75rem;
  text-transform: uppercase;
  letter-spacing: .08em;
  color: var(--color-text-subtle);
}

.matchup-header-value {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text-primary);
  word-break: break-word;
}

.matchup-header-game .matchup-header-value {
  font-size: 1.2rem;
  color: var(--color-accent-cyan);
}

/* Video Area */
.matchup-video-wrapper {
  display: flex;
  justify-content: center;
  margin-bottom: var(--space-xl);
}

.matchup-video-frame {
  position: relative;
  width: 100%;
  max-width: 900px;
  aspect-ratio: 16 / 9;
  border-radius: var(--radius-xl);
  border: 2px solid var(--color-border);
  background: #000;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.matchup-video {
  width: 100%;
  height: 100%;
  display: block;
}

/* Play/Pause Button — overlays the video */
.matchup-video-play {
  position: absolute;
  bottom: var(--space-sm);
  left: var(--space-sm);
  z-index: 2;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: var(--touch-target-min);
  min-height: var(--touch-target-min);
  padding: var(--space-sm) var(--space-md);
  font-size: .95rem;
  font-weight: 600;
  color: var(--color-text-heading);
  background: rgba(17, 21, 42, .85);
  border: 2px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  cursor: pointer;
  backdrop-filter: blur(4px);
  transition: background var(--duration-fast) var(--ease-standard), border-color var(--duration-fast) var(--ease-standard);
}

.matchup-video-play:hover {
  background: rgba(23, 29, 58, .9);
  border-color: var(--color-accent-blue);
}

.matchup-video-play:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 3px;
  box-shadow: var(--shadow-focus);
}

.matchup-video-play-icon {
  display: inline-block;
  margin-right: var(--space-2xs);
  font-size: 1.1rem;
}

/* Result Panel inside stage */
.matchup-result {
  margin-top: 0;
  background: transparent;
  border: none;
  padding: 0;
}

.matchup-result.hidden { display: none !important; }

.matchup-result-actions .replay-btn.hidden { display: none !important; }

.matchup-stage-actions {
  display: flex;
  justify-content: center;
  margin-top: var(--space-xl);
}

.matchup-result-title {
  font-size: 1.25rem;
  color: var(--color-text-heading);
  margin-bottom: var(--space-xl);
}

.matchup-result-actions {
  display: flex;
  gap: var(--space-sm);
  justify-content: center;
  margin-top: var(--space-xl);
  flex-wrap: wrap;
}

.matchup-stage-actions {
  display: flex;
  justify-content: center;
  margin-top: var(--space-xl);
}

.replay-btn, .new-matchup-btn {
  min-height: var(--touch-target-min);
  padding: var(--space-sm) var(--space-xl);
  font-size: .95rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: transform var(--duration-base) var(--ease-standard), box-shadow var(--duration-base) var(--ease-standard);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.replay-btn {
  color: var(--color-text-heading);
  background: linear-gradient(135deg, var(--color-accent-blue), var(--color-accent-violet));
  box-shadow: 0 3px 16px rgba(79, 125, 249, .25);
}

.replay-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 5px 24px rgba(79, 125, 249, .4);
}

.replay-btn:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 3px;
  box-shadow: var(--shadow-focus);
}

.new-matchup-btn {
  color: var(--color-text-heading);
  background: var(--color-surface-bg-alt);
  border: 2px solid var(--color-border-input);
}

.new-matchup-btn:hover {
  border-color: var(--color-accent-blue);
  color: var(--color-text-secondary);
}

.new-matchup-btn:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 3px;
  box-shadow: var(--shadow-focus);
}

.matchup-video-error-message {
  text-align: center;
  font-size: .9rem;
  color: var(--color-text-secondary);
  margin-top: var(--space-sm);
}

/* Matchup Result Stage — Responsive */
@media (max-width: 720px) {
  .matchup-header {
    grid-template-columns: 1fr;
    gap: var(--space-sm);
  }

  .matchup-result-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .replay-btn, .new-matchup-btn {
    width: 100%;
  }
}

/* Matchup Result Stage — Forced colors */
@media (forced-colors: active) {
  .matchup-stage,
  .matchup-result,
  .matchup-video-frame {
    border-color: CanvasText;
    forced-color-adjust: none;
  }

  .matchup-video-play {
    color: CanvasText;
    background: Canvas;
    border-color: CanvasText;
  }

  .replay-btn {
    color: Canvas;
    background: CanvasText;
  }
}

/* ─── Selected Generation Profile ──────────────────────────── */
.gen-profile {
  margin-top: var(--space-2xl);
  padding: var(--space-xl) var(--space-md);
  background: var(--color-panel-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
}

.profile-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--color-text-heading);
  margin-bottom: var(--space-2xs);
}

.profile-name {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-accent-cyan);
  margin-bottom: var(--space-2xs);
}

.profile-note {
  font-size: .9rem;
  color: var(--color-text-subtle);
  margin-bottom: var(--space-md);
}

.profile-table {
  width: 100%;
  border-collapse: collapse;
  font-size: .92rem;
}

.profile-table thead th,
.profile-table tbody td,
.profile-table tbody th {
  padding: .65rem .9rem;
  text-align: left;
  border-bottom: 1px solid var(--color-border-muted);
  vertical-align: middle;
}

.profile-table thead th {
  background: #141930;
  color: var(--color-text-subtle);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .06em;
  font-size: .78rem;
}

.profile-table thead th:first-child {
  border-radius: 10px 0 0 0;
}

.profile-table thead th:last-child {
  border-radius: 0 10px 0 0;
}

.profile-table tbody th {
  font-weight: 600;
  color: var(--color-text-secondary);
  white-space: nowrap;
}

.profile-table tbody td {
  white-space: nowrap;
}

.comparison-meter {
  display: inline-block;
  width: 100%;
  min-width: 90px;
  max-width: 220px;
  height: 12px;
  border-radius: var(--radius-sm);
  background: rgba(99, 160, 255, .12);
  overflow: hidden;
}

.comparison-fill {
  display: block;
  height: 100%;
  border-radius: var(--radius-sm);
  background: linear-gradient(90deg, var(--color-accent-blue), var(--color-accent-violet));
  transition: width var(--duration-slow) var(--ease-standard);
}

.comparison-value {
  font-variant-numeric: tabular-nums;
  color: var(--color-text-tertiary);
}

.profile-disclosure {
  margin-top: var(--space-sm);
  font-size: .8rem;
  line-height: 1.55;
  color: var(--color-text-subtle);
}

.profile-disclosure .methodology-link {
  color: var(--color-accent-cyan);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.profile-disclosure .methodology-link:focus-visible {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.source-list {
  margin: var(--space-md) 0 0;
  padding-left: var(--space-lg);
  color: var(--color-text-secondary);
  font-size: .9rem;
  line-height: 1.6;
}

/* ─── Footer ────────────────────────────────────────────────── */
.site-footer {
  text-align: center;
  padding: var(--space-3xl) var(--space-md);
  background: var(--color-page-bg-alt);
  color: var(--color-text-dim);
  font-size: .85rem;
  line-height: 1.6;
}

/* ═══════════════ Focus Styles (fallback) ═══════════════ */
.gen-card:focus,
.run-btn:focus,
.reset-btn:focus,
.cta-btn:focus,
.form-group select:focus,
.compare-btn:focus,
.swap-btn:focus,
.close-compare-btn:focus,
.compare-view-detail:focus {
  outline: var(--focus-ring-width) solid var(--color-focus-ring);
  outline-offset: 3px;
}

/* Forced colors support */
@media (forced-colors: active) {
  :root {
    --color-accent-blue: #0066cc;
    --color-accent-violet: #6600cc;
    --color-accent-cyan: #0099cc;
    --color-accent-teal: #009999;
    --color-accent-pink: #cc0099;
    --color-success: #008080;
    --color-warning: #d4af37;
    --color-focus-ring: #a78bfa;
  }

  body {
    color: CanvasText;
    background: Canvas;
  }

  .gen-card,
  .milestone-control,
  .milestone-panel,
  .detail-panel,
  .milestone-compare,
  .matchup-form,
  .matchup-result,
  .gen-profile,
  .compare-at-a-glance {
    border-color: CanvasText;
    forced-color-adjust: none;
  }

  .gen-card.active,
  .milestone-control.active {
    outline: var(--focus-ring-width) solid CanvasText;
  }

  a {
    color: LinkText;
  }

  .cta-btn,
  .compare-btn,
  .run-btn,
  .swap-btn {
    color: Canvas;
    background: CanvasText;
  }
}

/* ─── Reduced Motion ───────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important;
    transition-duration: .01ms !important;
  }
}

/* ═══════════════ Responsive ══════════════ */
@media (max-width: 720px) {
  .hero { min-height: 40vh; padding: var(--space-3xl) var(--space-md); }
  .generation-cards { grid-template-columns: 1fr; max-width: 400px; margin-left: auto; margin-right: auto; }
  .matchup-form { flex-direction: column; align-items: stretch; padding: var(--space-md); }
  .run-btn, .reset-btn { width: 100%; flex: none; min-width: 0; font-size: .85rem; padding: var(--space-xs) var(--space-sm); }
  .form-group { min-width: unset; }
  .form-buttons { justify-content: center; flex-wrap: wrap; }
  .run-btn, .reset-btn { flex: 1 1 auto; min-width: 100px; font-size: .88rem; padding: var(--space-xs) var(--space-sm); }
  .score-row { gap: var(--space-2xs); }
  .gen-profile { padding: var(--space-md); }
  .form-group select { width: 100%; max-width: 100%; min-width: 0; padding: var(--space-xs) var(--space-sm); font-size: .88rem; }
  .profile-name { font-size: 1rem; }
  .comparison-meter { min-width: 70px; max-width: none; }
  .milestones-timeline { flex-direction: column; }
  .milestone-control { flex: 1 1 auto; }
  .milestone-grid { grid-template-columns: 1fr !important; }
  .milestone-compare-header { flex-direction: column; align-items: flex-start; }
  .milestone-compare-selectors { flex-direction: column; }
  .milestone-compare-selectors .form-group { min-width: 0; flex: 1 1 100%; }
  .milestone-compare-grid { grid-template-columns: 1fr !important; }
  .milestone-compare-controls { width: 100%; justify-content: flex-end; }

  /* Matchup Result Stage */
  .matchup-header {
    grid-template-columns: 1fr;
    gap: var(--space-sm);
  }

  .matchup-result-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .replay-btn, .new-matchup-btn {
    width: 100%;
  }
}

@media (max-width: 390px) {
  .matchup-video-frame {
    max-width: 100%;
  }

  .matchup-header {
    gap: var(--space-xs);
  }

  .run-btn, .reset-btn { width: 100%; flex: none; min-width: 0; font-size: .78rem; padding: 8px 6px; white-space: normal; word-break: break-word; line-height: 1.15; }
  .form-buttons { flex-direction: column; align-items: stretch; gap: 10px; }
  .matchup-form { padding: 4px; }
}