:root {
  --text: #212529;
  --muted: #5f6872;
  --link: #1769aa;
  --border: #d9dde2;
  --light: #f5f6f7;
  --happy: #dca62f;
  --sad: #6f9fce;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  overflow-x: hidden;
  color: var(--text);
  background: #fff;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 16px;
  line-height: 1.55;
}
img { display: block; max-width: 100%; height: auto; }
a { color: var(--link); }
a:hover { text-decoration: underline; }
.skip-link { position: absolute; left: 12px; top: -60px; padding: 8px 12px; background: #fff; border: 1px solid var(--border); }
.skip-link:focus { top: 12px; }

.site-header,
main,
footer {
  width: min(1050px, calc(100% - 32px));
  margin: 0 auto;
}

.site-header {
  display: flex;
  justify-content: center;
  padding: 18px 0 12px;
  border-bottom: 1px solid var(--border);
}
.brand,
.menu-toggle { display: none; }
nav { display: flex; flex-wrap: wrap; justify-content: center; gap: 4px 16px; }
nav a { color: var(--link); text-decoration: none; }
nav .nav-cta { font-weight: 600; }

.hero {
  display: block;
  min-height: auto;
  padding: 38px 0 28px;
  text-align: center;
}
.hero-copy { max-width: 900px; margin: 0 auto; }
.eyebrow,
.section-kicker {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .04em;
  text-transform: uppercase;
}
h1, h2, h3 { color: var(--text); font-weight: 500; line-height: 1.2; }
h1 { margin: 0 0 12px; font-size: 32px; }
h2 { margin: 0 0 8px; font-size: 28px; }
h3 { margin: 0 0 6px; font-size: 20px; }
.hero-lede { max-width: 820px; margin: 0 auto 14px; color: var(--text); }
.hero-actions { display: flex; flex-wrap: wrap; justify-content: center; gap: 14px; margin: 14px 0; }
.button { display: inline-block; padding: 6px 12px; border: 1px solid var(--border); border-radius: 4px; color: var(--link); background: #fff; text-decoration: none; }
.button:hover { background: var(--light); text-decoration: none; }
.button-primary { color: #fff; border-color: var(--link); background: var(--link); }
.button-primary:hover { color: #fff; background: #12598f; }
.byline { margin: 12px 0 0; color: var(--muted); }
.signal-card { display: none; }

.section { padding: 32px 0; border-top: 1px solid var(--border); }
.intro { display: grid; grid-template-columns: 260px 1fr; gap: 36px; }
.intro-copy p:first-child { margin-top: 0; }
.llm-rationale {
  margin-top: 18px;
  padding: 12px 14px;
  border-left: 3px solid var(--happy);
  background: #fff9ec;
}
.llm-rationale strong { display: block; margin-bottom: 5px; }
.prompt-example {
  display: block;
  margin-top: 9px;
  padding: 7px 9px;
  border: 1px solid var(--border);
  background: #fff;
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
}
.section-heading { max-width: none; margin: 0 0 18px; }
.section-heading > p:last-child { margin-bottom: 0; color: var(--text); }

.snapshot-grid { display: grid; grid-template-columns: repeat(3, 1fr); border: 1px solid var(--border); }
.snapshot-grid article { padding: 14px; border-right: 1px solid var(--border); }
.snapshot-grid article:last-child { border-right: 0; }
.snapshot-grid article > span,
.metric-grid article > span { color: var(--muted); font-size: 13px; font-weight: 600; }
.snapshot-grid h3 { margin-top: 6px; }
.snapshot-grid p { margin-bottom: 0; }
.finding-banner,
.technical-note {
  margin: 14px 0 0;
  padding: 12px 14px;
  border-left: 3px solid var(--link);
  background: var(--light);
}
.finding-banner { display: block; color: var(--text); }
.finding-banner p { margin: 4px 0 0; }
.finding-label { font-weight: 600; }

.flow-list { margin: 0; padding: 0; border-top: 1px solid var(--border); list-style: none; }
.flow-list li { display: grid; grid-template-columns: 50px 150px 1fr; align-items: baseline; padding: 10px 0; border-bottom: 1px solid var(--border); }
.flow-list li > span { color: var(--muted); }
.flow-list h3 { margin: 0; font-size: 17px; }
.flow-list p { margin: 0; }
.feature-strip { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 14px; }
.feature-strip span { padding: 3px 9px; border: 1px solid var(--border); border-radius: 3px; background: #fff; }

.interface-grid { display: block; }
.interface-card { display: grid; grid-template-columns: 220px 1fr; gap: 18px; align-items: start; padding: 20px 0; border-top: 1px solid var(--border); }
.interface-card:last-child { border-bottom: 1px solid var(--border); }
.card-number { display: none; }
.card-copy p { margin-bottom: 0; }
.interface-card img { grid-column: 2; width: 100%; border: 1px solid var(--border); }
.interface-notes { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; margin-top: 24px; }
.interface-notes article { padding: 0; }
.interface-notes ol { margin-bottom: 0; padding-left: 22px; }
.interface-notes dl { margin-bottom: 0; }
.interface-notes dl div { display: grid; grid-template-columns: 1fr 1fr; padding: 5px 0; border-bottom: 1px solid var(--border); }
.interface-notes dd { margin: 0; }

.listen-preview { color: var(--text); background: #fff; }
.listen-preview h2,
.listen-preview h3 { color: var(--text); }
.listen-preview .section-kicker,
.listen-preview .section-heading > p:last-child,
.edits-heading p:last-child { color: var(--text); }
.audio-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.audio-grid-three,
.edit-grid { grid-template-columns: repeat(3, 1fr); }
.audio-card { padding: 12px; border: 1px solid var(--border); border-radius: 3px; background: #fff; }
.audio-card-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 10px; }
.audio-card-head > div { min-width: 0; }
.audio-card h3 { margin: 5px 0 8px; font-size: 16px; }
.audio-card p { min-height: 48px; margin: 0 0 8px; color: var(--muted); font-size: 14px; }
.audio-card audio { width: 100%; height: 38px; }
.audio-spectrogram { margin: 0 0 10px; overflow: hidden; border: 1px solid var(--border); background: #081c2c; }
.audio-spectrogram img { width: 100%; aspect-ratio: 2.42 / 1; object-fit: cover; }
.mos-score {
  flex: 0 0 auto;
  padding: 3px 7px;
  border: 1px solid #afd3e8;
  border-radius: 999px;
  color: #075381;
  background: #eef8fd;
  font-size: 11px;
  font-weight: 700;
  white-space: nowrap;
}
.audio-card-featured { border: 2px solid var(--border); }
.audio-tag { color: var(--muted); font-size: 12px; font-weight: 600; }
.audio-tag-warm,
.audio-tag-blue { color: var(--muted); }
.edits-heading { margin: 34px 0 14px; }
.edits-heading h3 { font-size: 24px; }
.praat-grid { max-width: 720px; }

.quality-summary { display: grid; grid-template-columns: minmax(210px, .7fr) minmax(0, 1.3fr); gap: 32px; align-items: start; }
.quality-summary .section-heading { margin: 0; }
.quality-table { margin-top: 0; }
.quality-table th:not(:first-child),
.quality-table td:not(:first-child) { text-align: center; }
.quality-table td:first-child { font-weight: 600; }
.quality-legend { margin: 10px 0 0; color: var(--muted); font-size: 14px; }

.trajectory-tabs { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 12px; }
.trajectory-tabs button { padding: 5px 10px; border: 1px solid var(--border); border-radius: 3px; color: var(--link); background: #fff; font: inherit; cursor: pointer; }
.trajectory-tabs button[aria-selected="true"] { color: #fff; border-color: var(--link); background: var(--link); }
.trajectory-frame,
.result-figure { margin: 0; padding: 8px; border: 1px solid var(--border); background: #fff; }
.trajectory-frame figcaption,
.result-figure figcaption { padding: 8px 4px 2px; color: var(--muted); text-align: center; font-size: 14px; }

.metric-grid { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--border); }
.metric-grid article { padding: 12px; border-right: 1px solid var(--border); }
.metric-grid article:last-child { border-right: 0; }
.metric-grid strong { display: block; margin: 3px 0; font-size: 22px; font-weight: 500; }
.metric-grid p { margin: 0; color: var(--muted); font-size: 13px; }
.result-layout { display: block; margin-top: 16px; }
.result-subsection { margin-top: 30px; padding-top: 24px; border-top: 1px solid var(--border); }
.original-validation { display: grid; grid-template-columns: minmax(0, 1.45fr) minmax(240px, .55fr); gap: 24px; align-items: start; }
.original-validation-copy h3 { margin-top: 0; }
.original-validation-copy p:last-child { margin-bottom: 0; }
.result-copy { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-top: 16px; }
.result-copy article { display: grid; grid-template-columns: 12px 1fr; gap: 8px; }
.result-copy p { margin: 0; }
.result-dot { width: 9px; height: 9px; margin-top: 6px; border-radius: 50%; background: var(--sad); }
.result-dot-happy { background: var(--happy); }
.table-wrap { margin-top: 18px; overflow-x: auto; border: 1px solid var(--border); }
table { width: 100%; border-collapse: collapse; white-space: nowrap; }
th, td { padding: 8px 10px; border-bottom: 1px solid var(--border); text-align: left; }
th { background: var(--light); font-weight: 600; }
tbody tr:last-child td { border-bottom: 0; }

.resources { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.resource-list { margin: 0; padding: 0; border-top: 1px solid var(--border); list-style: none; }
.resource-list a { display: grid; grid-template-columns: 80px 1fr; gap: 10px; padding: 9px 0; border-bottom: 1px solid var(--border); text-decoration: none; }
.resource-list span { color: var(--muted); font-size: 12px; }

footer { display: flex; justify-content: space-between; gap: 20px; padding: 24px 0 36px; border-top: 1px solid var(--border); color: var(--muted); font-size: 14px; }
footer p { margin: 0; }
footer .footer-credit { display: block; }
footer .ai-credit { margin-top: 4px; }
footer .footer-links { display: flex; flex-wrap: wrap; gap: 14px; }

@media (max-width: 760px) {
  .intro,
  .interface-card,
  .resources,
  .quality-summary,
  .original-validation { grid-template-columns: 1fr; gap: 12px; }
  .interface-card img { grid-column: 1; }
  .snapshot-grid,
  .metric-grid,
  .audio-grid,
  .audio-grid-three,
  .edit-grid { grid-template-columns: 1fr; }
  .snapshot-grid article,
  .metric-grid article { border-right: 0; border-bottom: 1px solid var(--border); }
  .snapshot-grid article:last-child,
  .metric-grid article:last-child { border-bottom: 0; }
  .flow-list li { grid-template-columns: 42px 105px 1fr; }
  .audio-card-head { display: block; }
  .mos-score { display: inline-block; margin-bottom: 7px; }
}

@media (max-width: 520px) {
  .site-header { justify-content: flex-start; overflow-x: auto; }
  nav { flex-wrap: nowrap; justify-content: flex-start; white-space: nowrap; }
  .interface-notes,
  .result-copy { grid-template-columns: 1fr; }
  .flow-list li { grid-template-columns: 36px 1fr; }
  .flow-list li div { grid-column: 2; }
  footer { display: block; }
  footer .footer-links { margin-top: 8px; }
}

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