:root {
  color-scheme: light;
  --page: #f5f6f8;
  --surface: #ffffff;
  --surface-subtle: #f8f9fa;
  --border: #d9dde3;
  --border-strong: #c4cad2;
  --text: #1f2933;
  --muted: #66717d;
  --link: #096b68;
  --workbench: #11181e;
  --workbench-panel: #182129;
  --workbench-border: #33414b;
  --workbench-text: #eef3f5;
  --workbench-muted: #aab5bc;
  --cyan: #62ddd6;
  --cyan-dark: #087d79;
  --yellow: #f1c453;
  --danger: #d64545;
  --radius: 8px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  min-width: 0;
  margin: 0;
  background: var(--page);
  color: var(--text);
  font-family: Inter, "Noto Sans SC", "Microsoft YaHei", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.6;
}

a { color: var(--link); }
button, input, select { font: inherit; }

button {
  min-height: 40px;
  padding: 0.5rem 0.85rem;
  border: 1px solid var(--border-strong);
  border-radius: 6px;
  background: var(--surface);
  color: var(--text);
  cursor: pointer;
}

button:hover { border-color: #88939f; background: var(--surface-subtle); }
button:disabled { cursor: not-allowed; opacity: 0.5; }
:focus-visible { outline: 3px solid rgba(8, 125, 121, 0.3); outline-offset: 2px; }

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.96);
}

.header-inner, .page-intro, .demo-section, .plain-section, .footer-inner {
  width: min(1280px, calc(100% - 2rem));
  margin-inline: auto;
}

.header-inner {
  display: flex;
  min-height: 56px;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.brand {
  color: var(--text);
  font-weight: 750;
  letter-spacing: 0.02em;
  text-decoration: none;
}

nav { display: flex; align-items: center; gap: 1.25rem; }
nav a { color: #4c5762; font-size: 0.9rem; text-decoration: none; }
nav a:hover { color: var(--text); }
main { padding-bottom: 4rem; }

.page-intro {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 2rem;
  padding-block: 2.25rem 1.5rem;
}

h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 0.3rem; font-size: clamp(1.75rem, 3vw, 2.45rem); line-height: 1.2; letter-spacing: -0.025em; }
h2 { margin-bottom: 0.25rem; font-size: clamp(1.35rem, 2vw, 1.7rem); line-height: 1.3; }
h3 { margin-bottom: 0.75rem; font-size: 1rem; }
.page-intro p, .section-heading p { margin-bottom: 0; color: var(--muted); }
.intro-links { display: flex; flex-shrink: 0; gap: 1rem; font-size: 0.9rem; }
.demo-section { margin-bottom: 3rem; }
.section-heading { margin-bottom: 1.25rem; }
.compact-heading, .split-heading { display: flex; align-items: end; justify-content: space-between; gap: 2rem; }
.compact-heading p { max-width: 48rem; }

.engine-status {
  display: flex;
  flex-shrink: 0;
  align-items: center;
  gap: 0.55rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.status-dot { width: 0.55rem; height: 0.55rem; border-radius: 50%; background: var(--yellow); }
.status-dot.ready { background: var(--cyan-dark); }
.status-dot.error { background: var(--danger); }

.workbench {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 330px;
  min-width: 0;
  overflow: hidden;
  border: 1px solid #26333d;
  border-radius: var(--radius);
  background: var(--workbench);
  box-shadow: 0 8px 24px rgba(31, 41, 51, 0.12);
}

.viewer-panel { min-width: 0; border-right: 1px solid var(--workbench-border); }
.stage { position: relative; aspect-ratio: 4 / 3; overflow: hidden; background: #05080a; }
.stage video, .stage canvas { position: absolute; inset: 0; width: 100%; height: 100%; }
.stage video { object-fit: contain; }
.stage canvas { cursor: crosshair; touch-action: none; }

.stage-message {
  position: absolute;
  inset: auto 1rem 1rem;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--workbench-border);
  border-radius: 5px;
  background: rgba(12, 18, 23, 0.9);
  color: var(--workbench-muted);
  font-size: 0.9rem;
}

.stage-message[hidden] { display: none; }

.transport, .rule-toolbar {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  min-width: 0;
  padding: 0.7rem 0.85rem;
  background: var(--workbench-panel);
}

.transport { border-top: 1px solid var(--workbench-border); }
.rule-toolbar { border-top: 1px solid var(--workbench-border); }
.rule-toolbar > label { color: var(--workbench-muted); font-size: 0.875rem; }
#rule-select { min-width: 6rem; min-height: 38px; padding: 0.3rem; border: 1px solid #46545e; border-radius: 6px; background: #202b33; color: var(--workbench-text); font-size: 0.875rem; }
.point-editor { display: flex; flex-wrap: wrap; gap: 0.5rem 1rem; max-height: 9rem; padding: 0.65rem 0.85rem; overflow-y: auto; border-top: 1px solid var(--workbench-border); background: var(--workbench-panel); color: var(--workbench-muted); font-size: 0.875rem; }
.point-pair { display: flex; align-items: center; gap: 0.45rem; }
.point-pair label { display: flex; align-items: center; gap: 0.25rem; }
.point-pair input { width: 5rem; min-height: 34px; padding: 0.25rem; border: 1px solid #46545e; border-radius: 4px; background: #11181e; color: var(--workbench-text); font-size: 0.875rem; }

.transport button, .rule-toolbar button, .inspector button {
  min-height: 38px;
  border-color: #46545e;
  background: #202b33;
  color: var(--workbench-text);
  font-size: 0.875rem;
}

.transport button:hover, .rule-toolbar button:hover, .inspector button:hover {
  border-color: #71808b;
  background: #26343d;
}

.transport .primary-control { border-color: #289b96; background: #147f7b; }
#timeline { min-width: 6rem; flex: 1; accent-color: var(--cyan); }
#frame-label { min-width: 4.5rem; color: var(--workbench-muted); font-size: 0.875rem; font-variant-numeric: tabular-nums; text-align: right; }
.toolbar-label, .rule-hint { color: var(--workbench-muted); font-size: 0.875rem; }

.segmented-control {
  display: inline-flex;
  padding: 2px;
  border: 1px solid #46545e;
  border-radius: 6px;
  background: #11181e;
}

.segmented-control .mode { min-height: 32px; padding: 0.25rem 0.7rem; border: 0; background: transparent; }
.segmented-control .mode.active { background: #2d3a43; color: var(--cyan); }
.rule-hint { margin-left: auto; }

.inspector {
  display: flex;
  min-width: 0;
  flex-direction: column;
  background: var(--workbench-panel);
  color: var(--workbench-text);
}

.inspector-section, .data-source { padding: 1rem; }
.inspector-section + .inspector-section, .data-source { border-top: 1px solid var(--workbench-border); }
.inspector h3 { margin-bottom: 0.6rem; color: var(--workbench-text); font-size: 0.95rem; }

.metric-list { display: grid; grid-template-columns: 1fr 1fr; margin: 0; }
.metric-list div { display: flex; align-items: baseline; justify-content: space-between; gap: 0.75rem; padding: 0.5rem 0; border-bottom: 1px solid rgba(70, 84, 94, 0.55); }
.metric-list div:nth-child(odd) { padding-right: 0.8rem; }
.metric-list div:nth-child(even) { padding-left: 0.8rem; border-left: 1px solid rgba(70, 84, 94, 0.55); }
.metric-list dt { color: var(--workbench-muted); font-size: 0.875rem; }
.metric-list dd { margin: 0; color: var(--cyan); font-weight: 700; font-variant-numeric: tabular-nums; }
.metric-note { margin: 0.65rem 0 0; color: var(--workbench-muted); font-size: 0.875rem; }

.class-counts { display: grid; max-height: 10rem; overflow-y: auto; }
.class-count-row { display: flex; align-items: baseline; justify-content: space-between; gap: 0.75rem; padding: 0.45rem 0; border-bottom: 1px solid rgba(70, 84, 94, 0.55); font-size: 0.875rem; }
.class-count-row span { color: var(--workbench-muted); }
.class-count-row strong { color: var(--workbench-text); font-weight: 600; font-variant-numeric: tabular-nums; text-align: right; }
.empty-class-count { margin: 0; color: var(--workbench-muted); font-size: 0.875rem; line-height: 1.5; }

.event-panel { min-height: 14rem; flex: 1; }
.panel-heading { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.panel-heading h3 { margin: 0; }
.panel-heading button { min-height: 32px; padding: 0.25rem 0.6rem; font-size: 0.875rem; }

#event-list {
  display: grid;
  gap: 0.65rem;
  max-height: 17rem;
  margin: 0.8rem 0 0;
  padding: 0 0 0 0.8rem;
  overflow: auto;
  border-left: 1px solid #53616b;
  list-style: none;
}

#event-list li { position: relative; color: #dfe7ea; font-size: 0.875rem; line-height: 1.5; }
#event-list li::before { position: absolute; top: 0.4rem; left: -1.05rem; width: 0.45rem; height: 0.45rem; border-radius: 50%; background: var(--yellow); content: ""; }
#event-list .empty-event { color: var(--workbench-muted); }
#event-list .empty-event::before { background: #53616b; }

.data-source { color: var(--workbench-muted); }
.data-source summary { color: var(--workbench-text); font-size: 0.9rem; cursor: pointer; }
.data-source p { margin: 0.6rem 0; font-size: 0.875rem; }
.file-field { display: grid; gap: 0.3rem; margin-top: 0.65rem; font-size: 0.875rem; }
.file-field input { width: 100%; color: var(--workbench-muted); font-size: 0.875rem; }

.plain-section { padding-block: 2.5rem; border-top: 1px solid var(--border); }

.pipeline {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin: 0;
  padding: 0;
  border-block: 1px solid var(--border);
  list-style: none;
}

.pipeline li { position: relative; display: grid; gap: 0.15rem; padding: 1.15rem 1.5rem 1.15rem 1rem; }
.pipeline li + li { border-left: 1px solid var(--border); }
.pipeline li:not(:last-child)::after { position: absolute; top: 50%; right: -0.45rem; z-index: 1; width: 0.8rem; height: 0.8rem; border-top: 1px solid var(--border-strong); border-right: 1px solid var(--border-strong); background: var(--page); content: ""; transform: translateY(-50%) rotate(45deg); }
.pipeline span, .pipeline small { color: var(--muted); font-size: 0.82rem; }
.pipeline strong { font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 0.95rem; }
.text-link { flex-shrink: 0; font-size: 0.9rem; }
.benchmark-links { display: flex; flex-wrap: wrap; gap: 0.5rem 1rem; }

.benchmark-result, .benchmark-empty { overflow-x: auto; border: 1px solid var(--border); border-radius: var(--radius); background: var(--surface); }
.benchmark-result[hidden], .benchmark-empty[hidden] { display: none; }
.benchmark-result > strong { display: block; padding: 0.85rem 1rem; border-bottom: 1px solid var(--border); }
.benchmark-empty { padding: 1rem; color: var(--muted); }
.benchmark-table { width: 100%; min-width: 36rem; border-collapse: collapse; }
.benchmark-table th, .benchmark-table td { padding: 0.75rem 1rem; border-bottom: 1px solid var(--border); text-align: left; font-variant-numeric: tabular-nums; }
.benchmark-table th { background: var(--surface-subtle); color: var(--muted); font-size: 0.82rem; font-weight: 600; }
.section-note { margin: 0.7rem 0 0; color: var(--muted); font-size: 0.85rem; }

.integration-layout { display: grid; grid-template-columns: minmax(0, 1.8fr) minmax(16rem, 0.7fr); gap: 1.5rem; }
.code-example { min-width: 0; overflow: hidden; border: 1px solid #26333d; border-radius: var(--radius); background: var(--workbench); }
.code-tabs { display: flex; gap: 0.25rem; padding: 0.45rem; border-bottom: 1px solid var(--workbench-border); background: var(--workbench-panel); }
.code-tab { min-height: 34px; padding: 0.3rem 0.7rem; border-color: transparent; background: transparent; color: var(--workbench-muted); font-size: 0.875rem; }
.code-tab:hover, .code-tab.active { border-color: #53616b; background: #26343d; color: var(--workbench-text); }
.code-panel { min-height: 13rem; padding: 1.15rem; }
.code-panel[hidden] { display: none; }

pre { margin: 0; overflow: auto; color: #dce9ec; font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 0.875rem; line-height: 1.65; white-space: pre; }
.input-boundaries { padding-left: 1.5rem; border-left: 1px solid var(--border); }
.input-boundaries ul { margin: 0; padding-left: 1.2rem; color: var(--muted); }
.input-boundaries li + li { margin-top: 0.45rem; }

footer { border-top: 1px solid var(--border); background: var(--surface); }
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 0.75rem 2rem; padding-block: 1.5rem; color: var(--muted); font-size: 0.82rem; }

@media (max-width: 980px) {
  .workbench { grid-template-columns: 1fr; }
  .viewer-panel { border-right: 0; border-bottom: 1px solid var(--workbench-border); }
  .pipeline { grid-template-columns: 1fr 1fr; }
  .pipeline li:nth-child(3) { border-left: 0; }
  .pipeline li:nth-child(n + 3) { border-top: 1px solid var(--border); }
  .pipeline li::after { display: none; }
}

@media (max-width: 720px) {
  .site-header { position: static; }
  .header-inner, .page-intro, .demo-section, .plain-section, .footer-inner { width: min(100% - 1.25rem, 1280px); }
  .header-inner { display: block; padding-block: 0.75rem; }
  nav { margin-top: 0.5rem; gap: 0.45rem 1rem; flex-wrap: wrap; }
  .page-intro, .compact-heading, .split-heading { display: block; }
  .intro-links, .engine-status, .text-link { margin-top: 0.8rem; }
  .transport { flex-wrap: wrap; }
  #timeline { order: 2; width: calc(100% - 5.5rem); flex-basis: calc(100% - 5.5rem); }
  #frame-label { order: 3; }
  .rule-toolbar { flex-wrap: wrap; }
  .point-editor { max-height: 12rem; }
  .pipeline, .integration-layout { grid-template-columns: 1fr; }
  .pipeline li + li, .pipeline li:nth-child(3) { border-left: 0; border-top: 1px solid var(--border); }
  .input-boundaries { padding: 1rem 0 0; border-top: 1px solid var(--border); border-left: 0; }
  .code-tabs { overflow-x: auto; }
  .code-tab { flex: 0 0 auto; }
}

@media (max-width: 420px) {
  .metric-list { grid-template-columns: 1fr; }
  .metric-list div:nth-child(odd), .metric-list div:nth-child(even) { padding-inline: 0; border-left: 0; }
  .footer-inner { display: grid; }
}

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