:root {
  --color-surface: #282327;
  --color-surface-alt: #373135;
  --color-surface-deep: #494247;
  --color-ink: #ccbdc7;
  --color-ink-soft: #a28a9b;
  --color-ink-muted: #8d7284;
  --color-line: #463f44;
  --color-primary: #e22ca6;
  --color-primary-ink: #181116;
  --color-primary-soft: #422439;
  --color-accent: #32ee11;
  --color-accent-ink: #181116;
  --color-highlight: #2a4823;
  --color-focus: #29fb04;
  --color-contrast-surface: #efecee;
  --color-contrast-ink: #332e31;
  --color-contrast-line: #c6c2c4;
  --color-contrast-accent: #1a7c09;
  --overlay-scrim: linear-gradient(180deg, rgba(239, 236, 238, 0.35) 0%, rgba(239, 236, 238, 0.72) 55%, rgba(239, 236, 238, 0.92) 100%);
  --font-heading: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-body: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --text-xs: 11.4px;
  --text-sm: 14.3px;
  --text-base: 16px;
  --text-lg: 20.0px;
  --text-xl: 25.0px;
  --text-2xl: 31.2px;
  --text-3xl: 39.1px;
  --text-4xl: 48.8px;
  --text-display: clamp(44px, 9.0vw, 115px);
  --text-figure: clamp(37px, 6.5vw, 83px);
  --weight-heading: 658;
  --weight-body: 400;
  --leading-body: 1.82;
  --leading-heading: 1.2;
  --tracking-heading: -0.007em;
  --radius-sm: 8px;
  --radius-md: 8px;
  --radius-lg: 8px;
  --radius-pill: 999px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: 0 0 0 1px rgba(50, 238, 17, 0.35);
  --shadow-2: 0 0 28px rgba(50, 238, 17, 0.35);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1260px;
  --measure: 69ch;
  --gutter: 32px;
  --section-y: 92px;
  --section-y-lg: 129px;
}

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 96px; }
body {
  margin: 0;
  background-color: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-body);
  line-height: var(--leading-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-wrap: break-word;
}
img, svg, video { max-width: 100%; display: block; }
button { font: inherit; color: inherit; }
ul, ol { margin: 0; padding: 0; }
[hidden] { display: none !important; }

/* ---------- 中文排版与基础元素 ---------- */
h1, h2, h3, h4 {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
h1 { font-size: var(--text-3xl); }
h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }
p { margin: 0; }
a { color: inherit; text-decoration: none; }
strong { font-weight: var(--weight-heading); color: var(--color-ink); }
code, kbd, samp, time { font-family: var(--font-mono); }
::selection { background: var(--color-primary); color: var(--color-primary-ink); }

:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

.skip-link {
  position: fixed;
  left: var(--space-2);
  top: var(--space-2);
  z-index: 200;
  transform: translateY(-220%);
  display: inline-block;
  padding: 10px 16px;
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  border-radius: var(--radius-sm);
  transition: transform 180ms ease;
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 布局工具 ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.section--tight { padding-block: var(--space-6); }
.section--alt { background-color: var(--color-surface-alt); }
.section--deep { background-color: var(--color-surface-deep); }
.section--contrast { background-color: var(--color-contrast-surface); color: var(--color-contrast-ink); }
.section--contrast h2, .section--contrast h3 { color: var(--color-contrast-ink); }

.prose { max-width: var(--measure); font-size: var(--text-base); color: var(--color-ink); }
.prose p + p { margin-top: var(--space-2); }
.prose ul { margin-top: var(--space-2); padding-left: 1.2em; }
.prose li + li { margin-top: var(--space-1); }

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}
.span-2 { grid-column: span 2; }
.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-9 { grid-column: span 9; }
.span-12, .span-full { grid-column: 1 / -1; }

.page-head { padding-top: var(--space-6); padding-bottom: var(--space-4); display: grid; gap: var(--space-2); }
.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.16em;
  color: var(--color-ink-muted);
}
.hero-title {
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: 0.98;
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
.figure-num {
  display: inline-flex;
  align-items: baseline;
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--color-ink);
}
.figure-num__unit { font-size: var(--text-lg); color: var(--color-ink-muted); margin-left: 6px; }
.figure-label {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

/* ---------- 头部：框架式导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background-color: color-mix(in srgb, var(--color-surface) 92%, transparent);
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 26%, var(--color-line));
  box-shadow: 0 14px 34px rgba(0, 0, 0, 0.42);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  transition: background-color 180ms ease, box-shadow 180ms ease;
}
.site-header.is-scrolled {
  background-color: color-mix(in srgb, var(--color-surface) 97%, transparent);
  box-shadow: 0 18px 42px rgba(0, 0, 0, 0.55);
}
.site-header__frame {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  width: 100%;
  max-width: var(--container);
  min-height: 72px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.site-header__frame::before,
.site-header__frame::after {
  content: "";
  flex: 0 0 1px;
  align-self: stretch;
  background: linear-gradient(180deg,
    transparent 0%,
    color-mix(in srgb, var(--color-primary) 45%, transparent) 45%,
    color-mix(in srgb, var(--color-accent) 30%, transparent) 60%,
    transparent 100%);
}
.brand { min-width: 0; }
.brand__link { display: flex; align-items: baseline; gap: var(--space-2); flex-wrap: wrap; }
.brand__mark {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  text-shadow: 0 0 20px color-mix(in srgb, var(--color-primary) 40%, transparent);
}
.brand__note {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
  white-space: nowrap;
}
.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-1);
  margin-left: auto;
  padding: 8px 12px;
  background: transparent;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  color: var(--color-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  cursor: pointer;
  transition: border-color 180ms ease, background-color 180ms ease, box-shadow 180ms ease;
}
.nav-toggle__bars {
  position: relative;
  display: inline-block;
  width: 16px;
  height: 12px;
  border-top: 1px solid currentColor;
  border-bottom: 1px solid currentColor;
}
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 50%;
  height: 1px;
  background: currentColor;
}
.nav-toggle[aria-expanded="true"] {
  border-color: color-mix(in srgb, var(--color-primary) 70%, transparent);
  background-color: var(--color-primary-soft);
  box-shadow: var(--shadow-1);
}
.site-nav { margin-left: auto; }
.site-nav__list { display: flex; align-items: center; list-style: none; }
.site-nav__item + .site-nav__item { border-left: var(--border-thin) solid var(--color-line); }
.site-nav__link {
  display: inline-block;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-sm);
  transition: color 180ms ease, border-color 180ms ease, background-color 180ms ease, box-shadow 180ms ease;
}
.site-nav__link:hover {
  color: var(--color-ink);
  border-color: color-mix(in srgb, var(--color-accent) 40%, transparent);
  box-shadow: var(--shadow-1);
}
.site-nav__link[aria-current="page"] {
  color: var(--color-ink);
  border-color: color-mix(in srgb, var(--color-primary) 72%, transparent);
  background-color: color-mix(in srgb, var(--color-primary-soft) 78%, transparent);
  box-shadow: 0 0 18px color-mix(in srgb, var(--color-primary) 34%, transparent);
}
.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: transparent;
  pointer-events: none;
}
.scroll-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--color-accent), var(--color-primary));
  box-shadow: 0 0 12px color-mix(in srgb, var(--color-accent) 55%, transparent);
  transition: width 120ms linear;
}

/* ---------- 页脚：阶梯式 ---------- */
.site-footer {
  margin-top: var(--section-y);
  background-color: var(--color-surface-alt);
  border-top: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 24%, var(--color-line));
}
.site-footer__inner {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.footer-index {
  display: grid;
  grid-template-columns: minmax(220px, 1fr) minmax(0, 2.2fr);
  gap: var(--space-6);
  padding: var(--space-8) 0 var(--space-6);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.footer-brand__mark {
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
.footer-brand__note {
  margin-top: var(--space-1);
  max-width: 34ch;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}
.footer-brand__cta { margin-top: var(--space-3); }
.footer-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-4);
}
.footer-nav__group + .footer-nav__group {
  border-left: var(--border-thin) solid var(--color-line);
  padding-left: var(--space-3);
}
.footer-nav__title {
  margin-bottom: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--weight-body);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
}
.footer-nav__list { list-style: none; display: grid; gap: 10px; }
.footer-nav__link {
  display: inline-block;
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  border-bottom: var(--border-thin) solid transparent;
  padding-bottom: 2px;
  transition: color 180ms ease, border-color 180ms ease;
}
.footer-nav__link:hover {
  color: var(--color-ink);
  border-bottom-color: var(--color-primary);
}
.footer-nav__link--legacy {
  color: var(--color-ink-muted);
  border-bottom-color: var(--color-line);
}
.footer-nav__link--legacy:hover { border-bottom-color: var(--color-ink-muted); }
.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-6);
  margin-inline: calc(var(--gutter) * -1);
  padding: var(--space-4) var(--gutter) var(--space-6);
  background-color: var(--color-surface);
  border-top: var(--border-thin) solid var(--color-line);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
}
.footer-legal__item { display: inline-flex; align-items: baseline; gap: var(--space-1); }
.footer-legal__item--wide { flex-basis: 100%; }
.footer-legal__item--muted { flex-basis: 100%; color: var(--color-ink-muted); }
.footer-legal__key { color: var(--color-ink-muted); }
.footer-legal__val { color: var(--color-ink-soft); }

/* ---------- 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  padding-block: var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}
.breadcrumb ol { display: flex; flex-wrap: wrap; align-items: center; list-style: none; gap: var(--space-1); }
.breadcrumb li { display: inline-flex; align-items: center; gap: var(--space-1); }
.breadcrumb li + li::before { content: "/"; color: var(--color-line); }
.breadcrumb a { color: var(--color-ink-soft); border-bottom: var(--border-thin) solid transparent; }
.breadcrumb a:hover { color: var(--color-ink); border-bottom-color: var(--color-primary); }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 11px 18px;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-ink);
  background: transparent;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: color 180ms ease, border-color 180ms ease, background-color 180ms ease, box-shadow 180ms ease;
}
.btn:hover { border-color: color-mix(in srgb, var(--color-primary) 60%, transparent); box-shadow: var(--shadow-1); }
.btn--primary {
  border-color: transparent;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  box-shadow: 0 0 22px color-mix(in srgb, var(--color-primary) 42%, transparent);
}
.btn--primary:hover { box-shadow: 0 0 30px color-mix(in srgb, var(--color-primary) 58%, transparent); }
.btn--ghost { border-color: color-mix(in srgb, var(--color-primary) 55%, transparent); }
.btn--ghost:hover { background-color: var(--color-primary-soft); }
.btn--accent {
  border-color: transparent;
  background-color: var(--color-accent);
  color: var(--color-accent-ink);
  box-shadow: var(--shadow-2);
}

/* ---------- 标签与强调 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  line-height: 1.7;
}
.tag--primary {
  color: var(--color-ink);
  border-color: color-mix(in srgb, var(--color-primary) 62%, transparent);
  background-color: color-mix(in srgb, var(--color-primary-soft) 70%, transparent);
}
.tag--accent {
  color: var(--color-accent);
  border-color: color-mix(in srgb, var(--color-accent) 55%, transparent);
  background-color: var(--color-highlight);
}
.mark {
  color: var(--color-ink);
  border-bottom: var(--border-thin) solid var(--color-primary);
  padding-bottom: 1px;
}
.mark--accent {
  background-color: var(--color-highlight);
  border-bottom-color: transparent;
  border-radius: 3px;
  padding: 1px 4px;
}

/* ---------- 章节头与刻度分隔 ---------- */
.section-head { display: grid; gap: var(--space-2); margin-bottom: var(--space-6); }
.section-head__num {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.1em;
  color: var(--color-accent);
}
.section-head__title {
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
}
.section-head__lead { max-width: var(--measure); color: var(--color-ink-soft); }
.rule-scale {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}
.rule-scale::before,
.rule-scale::after {
  content: "";
  flex: 1 1 auto;
  height: 1px;
  background: var(--color-line);
}

/* ---------- 卡片 ---------- */
.card {
  display: grid;
  gap: var(--space-2);
  padding: var(--space-3);
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  transition: border-color 180ms ease, transform 180ms ease, box-shadow 180ms ease;
}
.card:hover {
  border-color: color-mix(in srgb, var(--color-primary) 55%, transparent);
  transform: translateY(-4px);
  box-shadow: 0 0 24px color-mix(in srgb, var(--color-primary) 24%, transparent);
}
.card__title { font-size: var(--text-lg); }
.card__meta { font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-ink-muted); }
.card__text { color: var(--color-ink-soft); font-size: var(--text-base); }

/* ---------- 编号刻度清单 ---------- */
.scale-list { list-style: none; display: grid; }
.scale-list__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: var(--space-2);
  align-items: baseline;
  padding: 14px 0;
  border-bottom: var(--border-thin) solid var(--color-line);
}
.scale-list__num { font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-accent); min-width: 3em; }
.scale-list__label { color: var(--color-ink); }
.scale-list__value { font-family: var(--font-mono); font-size: var(--text-sm); color: var(--color-ink-soft); }

/* ---------- 纵向阶梯时间线 ---------- */
.timeline-v { list-style: none; }
.timeline-v__item {
  position: relative;
  padding: 0 0 var(--space-6) var(--space-4);
  border-left: var(--border-thin) solid var(--color-line);
}
.timeline-v__item::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 8px;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--color-surface);
  border: var(--border-thin) solid var(--color-primary);
  box-shadow: 0 0 10px color-mix(in srgb, var(--color-primary) 60%, transparent);
}
.timeline-v__item:last-child { border-left-color: transparent; padding-bottom: 0; }
.timeline-v__year {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}
.timeline-v__title { font-size: var(--text-lg); }
.timeline-v__text { color: var(--color-ink-soft); max-width: var(--measure); }

/* ---------- 步骤路径 ---------- */
.steps { list-style: none; display: grid; gap: var(--space-3); }
.steps__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: var(--space-3);
  align-items: start;
  padding: var(--space-3);
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-left: 2px solid color-mix(in srgb, var(--color-accent) 70%, transparent);
  border-radius: var(--radius-md);
}
.steps__num { font-family: var(--font-mono); font-size: var(--text-lg); line-height: 1; color: var(--color-accent); }
.steps__title { font-size: var(--text-lg); margin-bottom: 4px; }
.steps__text { color: var(--color-ink-soft); }

/* ---------- 数据表 ---------- */
.data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}
.data-table th,
.data-table td {
  padding: 12px var(--space-2);
  text-align: left;
  line-height: 44px;
  border-bottom: var(--border-thin) solid var(--color-line);
}
.data-table th {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--weight-body);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}
.data-table td { color: var(--color-ink); }
.data-table tbody tr:hover { background-color: color-mix(in srgb, var(--color-surface-deep) 55%, transparent); }
.data-table__num { font-family: var(--font-mono); color: var(--color-accent); }

/* ---------- 浅色对照层（旧版口径） ---------- */
.legacy-panel {
  padding: var(--space-4);
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: var(--border-thin) solid var(--color-contrast-line);
  border-radius: var(--radius-md);
  font-size: calc(var(--text-base) * 0.94);
}
.legacy-panel__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2);
  padding-bottom: var(--space-2);
  margin-bottom: var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
}
.legacy-panel__title { font-size: var(--text-lg); color: var(--color-contrast-ink); }
.legacy-panel__note { font-family: var(--font-mono); font-size: var(--text-xs); color: var(--color-contrast-accent); }
.legacy-panel .data-table th { color: color-mix(in srgb, var(--color-contrast-ink) 70%, var(--color-contrast-surface)); }
.legacy-panel .data-table th,
.legacy-panel .data-table td { border-bottom-color: var(--color-contrast-line); color: var(--color-contrast-ink); line-height: 1.7; }
.legacy-panel .data-table__num { color: var(--color-contrast-accent); }
.legacy-panel .mark { color: var(--color-contrast-ink); border-bottom-color: var(--color-contrast-accent); }

/* ---------- 图片容器 ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
}
.media-frame__img {
  width: 100%;
  height: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: inherit;
}
.media-frame--wide .media-frame__img { aspect-ratio: 16 / 9; }
.media-frame--tall .media-frame__img { aspect-ratio: 3 / 4; }
.media-frame__scrim {
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
}
.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2;
  padding: var(--space-2) var(--space-3);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-contrast-ink);
}
.media-frame__tag {
  position: absolute;
  left: var(--space-2);
  top: var(--space-2);
  z-index: 2;
  padding: 3px 10px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-primary-ink);
  background-color: var(--color-primary);
  border-radius: var(--radius-pill);
}

/* ---------- 锚点目录 ---------- */
.toc {
  display: grid;
  gap: 10px;
  padding-left: var(--space-3);
  border-left: var(--border-thin) solid var(--color-line);
}
.toc__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
  transition: color 180ms ease;
}
.toc__link:hover { color: var(--color-ink); }
.toc__link.is-active { color: var(--color-accent); }

/* ---------- 筛选 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  padding-block: var(--space-2);
  border-top: var(--border-thin) solid var(--color-line);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.filter-chip {
  padding: 6px 12px;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-soft);
  background: transparent;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: color 180ms ease, border-color 180ms ease, background-color 180ms ease;
}
.filter-chip:hover { color: var(--color-ink); border-color: color-mix(in srgb, var(--color-accent) 45%, transparent); }
.filter-chip[aria-pressed="true"] {
  color: var(--color-ink);
  border-color: color-mix(in srgb, var(--color-primary) 65%, transparent);
  background-color: var(--color-primary-soft);
}

/* ---------- 折叠 ---------- */
.disclosure {
  background-color: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.disclosure + .disclosure { margin-top: var(--space-2); }
.disclosure__btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-3);
  background: transparent;
  border: 0;
  text-align: left;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  color: var(--color-ink);
  cursor: pointer;
}
.disclosure__icon { font-family: var(--font-mono); color: var(--color-accent); }
.disclosure__icon::before { content: "+"; }
.disclosure[data-open="true"] .disclosure__icon::before { content: "−"; }
.disclosure[data-open="true"] { border-color: color-mix(in srgb, var(--color-primary) 50%, transparent); }
.disclosure__body { display: none; padding: 0 var(--space-3) var(--space-3); color: var(--color-ink-soft); }
.disclosure[data-open="true"] .disclosure__body { display: block; }

/* ---------- 显现 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 240ms ease, transform 240ms ease;
}
.reveal.is-visible { opacity: 1; transform: none; }

/* ---------- 平板 ---------- */
@media (max-width: 1024px) {
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .span-2, .span-3, .span-4 { grid-column: span 3; }
  .span-5, .span-6 { grid-column: span 6; }
  .span-7, .span-8, .span-9, .span-12, .span-full { grid-column: 1 / -1; }
  .footer-index { grid-template-columns: 1fr; gap: var(--space-4); }
  .footer-nav { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (max-width: 900px) {
  .nav-toggle { display: inline-flex; }
  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: none;
    margin-left: 0;
    max-height: calc(100vh - 72px);
    overflow-y: auto;
    background-color: var(--color-surface-alt);
    border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-primary) 40%, var(--color-line));
    box-shadow: 0 24px 40px rgba(0, 0, 0, 0.5);
  }
  .site-nav[data-open="true"] { display: block; }
  .site-nav__list { flex-direction: column; align-items: stretch; }
  .site-nav__item + .site-nav__item {
    border-left: 0;
    border-top: var(--border-thin) solid var(--color-line);
  }
  .site-nav__link {
    display: block;
    padding: 14px var(--gutter);
    border: 0;
    border-radius: 0;
  }
  .site-nav__link[aria-current="page"] {
    background-color: var(--color-primary-soft);
    box-shadow: inset 2px 0 0 var(--color-primary);
  }
  .site-header__frame::before,
  .site-header__frame::after { display: none; }
}
/* ---------- 手机 ---------- */
@media (max-width: 720px) {
  :root { --gutter: 20px; }
  .grid-12 { grid-template-columns: 1fr; gap: var(--space-4); }
  .span-2, .span-3, .span-4, .span-5, .span-6, .span-7, .span-8, .span-9, .span-12, .span-full { grid-column: 1 / -1; }
  .site-header__frame { min-height: 64px; gap: var(--space-2); }
  .brand__link { flex-direction: column; align-items: flex-start; gap: 0; }
  .brand__mark { font-size: var(--text-lg); }
  .brand__note { font-size: var(--text-xs); white-space: normal; }
  .footer-nav { grid-template-columns: 1fr; gap: var(--space-3); }
  .footer-nav__group + .footer-nav__group {
    border-left: 0;
    border-top: var(--border-thin) solid var(--color-line);
    padding-left: 0;
    padding-top: var(--space-3);
  }
  .footer-index { padding-top: var(--space-6); }
  .footer-legal { flex-direction: column; gap: var(--space-1); margin-inline: calc(var(--gutter) * -1); }
  .footer-legal__item--wide, .footer-legal__item--muted { flex-basis: auto; }
  .scale-list__item { grid-template-columns: auto minmax(0, 1fr); }
  .scale-list__value { grid-column: 2; }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .reveal { opacity: 1; transform: none; }
  .card:hover { transform: none; }
}