:root {
  --bg: #f7f6f3;
  --bg-warm: #f0eeea;
  --surface: #ffffff;
  --surface-raised: #f5f4f1;
  --border: rgba(0,0,0,0.08);
  --border-hover: rgba(0,0,0,0.15);
  --text: #1a1a1a;
  --text-secondary: #5a5660;
  --text-dim: #8a8690;
  --accent: #9a7b2e;
  --accent-muted: #b08f3a;
  --accent-glow: rgba(154,123,46,0.07);
  --teal: #1a8a80;
  --teal-bg: rgba(26,138,128,0.07);
  --coral: #b84a3a;
  --coral-bg: rgba(184,74,58,0.06);
  --radius: 14px;
  --radius-sm: 8px;
  --font-display: 'Instrument Serif', Georgia, serif;
  --font-body: 'Outfit', system-ui, sans-serif;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  color-scheme: light;
}

body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* ── Grain overlay ── */
.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 9999;
  opacity: 0.018;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 512 512' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.7' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-repeat: repeat;
  background-size: 256px 256px;
}

/* ── Hero ── */
.hero {
  position: relative;
  text-align: center;
  padding: 100px 32px 72px;
  background:
    radial-gradient(ellipse 80% 60% at 25% 40%, rgba(154,123,46,0.06) 0%, transparent 70%),
    radial-gradient(ellipse 60% 50% at 75% 60%, rgba(26,138,128,0.04) 0%, transparent 70%),
    linear-gradient(180deg, var(--bg-warm) 0%, var(--bg) 100%);
  overflow: hidden;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--accent-muted), transparent);
  opacity: 0.3;
}

.eyebrow {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 28px;
  padding: 6px 18px;
  border: 1px solid rgba(154,123,46,0.25);
  border-radius: 100px;
  animation: fadeDown 0.8s var(--ease-out) both;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.2rem, 5.5vw, 3.8rem);
  font-weight: 400;
  line-height: 1.15;
  color: var(--text);
  margin-bottom: 20px;
  letter-spacing: -0.01em;
  animation: fadeDown 0.8s var(--ease-out) 0.1s both;
}

.subtitle {
  font-family: var(--font-display);
  font-style: italic;
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--text-secondary);
  margin-bottom: 12px;
  animation: fadeDown 0.8s var(--ease-out) 0.2s both;
}

.desc {
  max-width: 540px;
  margin: 0 auto 40px;
  font-size: 0.92rem;
  color: var(--text-dim);
  line-height: 1.7;
  animation: fadeDown 0.8s var(--ease-out) 0.3s both;
}

/* ── TOC nav ── */
.toc {
  display: flex;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
  animation: fadeDown 0.8s var(--ease-out) 0.4s both;
}

.toc a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 22px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 100px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  transition: all 0.3s var(--ease-out);
}

.toc-num {
  font-size: 0.65rem;
  font-weight: 700;
  color: var(--accent-muted);
  opacity: 0.6;
}

.toc a:hover {
  background: var(--accent-glow);
  border-color: rgba(154,123,46,0.3);
  color: var(--accent);
  transform: translateY(-1px);
  box-shadow: 0 4px 20px rgba(154,123,46,0.08);
}

.toc a:hover .toc-num {
  opacity: 1;
}

/* ── Main ── */
main {
  max-width: 920px;
  margin: 0 auto;
  padding: 0 28px 100px;
}

/* ── Section reveal ── */
.reveal {
  opacity: 0;
  transform: translateY(32px);
  transition: opacity 0.7s var(--ease-out), transform 0.7s var(--ease-out);
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ── Section header ── */
.eval-section {
  margin-top: 80px;
}

.section-header {
  position: relative;
  margin-bottom: 40px;
  padding-bottom: 24px;
}

.section-header::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--accent-muted), transparent 80%);
  opacity: 0.25;
}

.section-num {
  display: block;
  font-family: var(--font-display);
  font-size: 0.85rem;
  color: var(--accent-muted);
  opacity: 0.5;
  margin-bottom: 6px;
  letter-spacing: 0.05em;
}

.section-header h2 {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 400;
  color: var(--text);
  margin-bottom: 10px;
}

.section-desc {
  font-size: 0.9rem;
  color: var(--text-dim);
  max-width: 600px;
  line-height: 1.7;
}

/* ── Edit group ── */
.edit-group {
  margin-top: 40px;
}

.edit-group h3 {
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 18px;
  padding-left: 16px;
  position: relative;
}

.edit-group h3::before {
  content: '';
  position: absolute;
  left: 0;
  top: 2px;
  bottom: 2px;
  width: 3px;
  background: var(--accent);
  border-radius: 3px;
  opacity: 0.6;
}

/* ── Clip pair card ── */
.clip-pair {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin-bottom: 14px;
  transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

.clip-pair:hover {
  border-color: var(--border-hover);
  box-shadow: 0 8px 40px rgba(0,0,0,0.06);
}

/* ── Audio row ── */
.audio-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 12px;
}

.audio-cell {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.audio-tag {
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  padding: 4px 12px;
  border-radius: 6px;
  width: fit-content;
}

.tag-original {
  color: var(--teal);
  background: var(--teal-bg);
  border: 1px solid rgba(26,138,128,0.15);
}

.tag-edited {
  color: var(--coral);
  background: var(--coral-bg);
  border: 1px solid rgba(184,74,58,0.12);
}

audio {
  width: 100%;
  height: 36px;
  border-radius: var(--radius-sm);
  outline: none;
}

audio::-webkit-media-controls-panel {
  background: var(--surface-raised);
}

/* ── Metrics table ── */
.metrics-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.metrics-table th,
.metrics-table td {
  padding: 5px 10px;
  border-bottom: 1px solid var(--border);
}

.metrics-table tr:last-child th,
.metrics-table tr:last-child td {
  border-bottom: none;
}

.metrics-table th {
  text-align: left;
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-dim);
  background: var(--bg-warm);
  white-space: nowrap;
  width: 1%;
}

.metrics-table td {
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  color: var(--accent);
  background: var(--surface-raised);
  white-space: nowrap;
}

.metrics-table .metric-name {
  font-weight: 500;
  color: var(--text-secondary);
  font-size: 0.75rem;
  background: var(--surface);
}

/* ── Footer ── */
footer {
  padding: 0 28px;
  max-width: 920px;
  margin: 0 auto;
}

.footer-rule {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border-hover), transparent);
}

/* ── Animations ── */
@keyframes fadeDown {
  from {
    opacity: 0;
    transform: translateY(-16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ── Responsive ── */
@media (max-width: 640px) {
  .hero {
    padding: 64px 20px 48px;
  }

  .hero h1 {
    font-size: 2rem;
  }

  main {
    padding: 0 16px 64px;
  }

  .audio-row {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .clip-pair {
    padding: 18px 16px;
  }

  .metrics-table {
    font-size: 0.72rem;
  }

  .metrics-table th,
  .metrics-table td {
    padding: 4px 8px;
  }

  .toc {
    gap: 8px;
  }

  .toc a {
    padding: 8px 16px;
    font-size: 0.8rem;
  }

  .section-header h2 {
    font-size: 1.5rem;
  }
}

@media (max-width: 400px) {
  .hero h1 {
    font-size: 1.7rem;
  }

  .toc a {
    flex: 1;
    justify-content: center;
    min-width: 120px;
  }
}