:root {
  --color-surface: #f4f4f3;
  --color-surface-alt: #ecebea;
  --color-surface-deep: #e0dfde;
  --color-ink: #4e4441;
  --color-ink-soft: #736763;
  --color-ink-muted: #887b77;
  --color-line: #d6d4d3;
  --color-primary: #c55030;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #edddd8;
  --color-accent: #3075ca;
  --color-accent-ink: #ffffff;
  --color-highlight: #d1ddec;
  --color-focus: #216dc9;
  --color-contrast-surface: #251915;
  --color-contrast-ink: #e7e5e4;
  --color-contrast-line: #504643;
  --color-contrast-accent: #4685d3;
  --overlay-scrim: linear-gradient(180deg, rgba(37, 25, 21, 0.35) 0%, rgba(37, 25, 21, 0.72) 55%, rgba(37, 25, 21, 0.92) 100%);
  --font-heading: "Songti SC", "Source Han Serif SC", "Noto Serif SC", SimSun, serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
  --font-mono: ui-monospace, Menlo, Consolas, monospace;
  --text-xs: 11.7px;
  --text-sm: 15.6px;
  --text-base: 18px;
  --text-lg: 24.0px;
  --text-xl: 32.0px;
  --text-2xl: 42.6px;
  --text-3xl: 56.8px;
  --text-4xl: 75.8px;
  --text-display: clamp(34px, 6.2vw, 80px);
  --text-figure: clamp(28px, 4.5vw, 58px);
  --weight-heading: 642;
  --weight-body: 400;
  --leading-body: 1.88;
  --leading-heading: 1.16;
  --tracking-heading: -0.007em;
  --radius-sm: 0px;
  --radius-md: 0px;
  --radius-lg: 1px;
  --radius-pill: 1px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: none;
  --shadow-2: none;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1200px;
  --measure: 64ch;
  --gutter: 24px;
  --section-y: 77px;
  --section-y-lg: 108px;
}

/* ============================================================
   1. RESET / 基础
   ============================================================ */
*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

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);
  padding-bottom: 72px;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

img, svg, video { display: block; max-width: 100%; height: auto; }
figure { margin: 0; }
ul, ol { margin: 0 0 var(--space-3); padding-left: 1.35em; }
li { margin-bottom: 6px; }
p { margin: 0 0 var(--space-3); }
a { color: inherit; }
button { font: inherit; color: inherit; }
hr { border: 0; }

::selection { background: var(--color-highlight); color: var(--color-ink); }

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

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-2);
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  text-wrap: balance;
}
h1 { font-size: var(--text-3xl); }
h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }
h5, h6 { font-size: var(--text-base); }

/* ============================================================
   2. 工具类
   ============================================================ */
.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.01em;
}

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

.link-underline {
  text-decoration: none;
  background-image: linear-gradient(currentColor, currentColor);
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0 1px;
  padding-bottom: 1px;
  transition: background-size 160ms linear, color 140ms linear;
}
.link-underline:hover,
.link-underline:focus-visible { background-size: 100% 1px; }

/* ============================================================
   3. 容器 / 栅格 / 区块
   ============================================================ */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}
.col-2 { grid-column: span 2; }
.col-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-9 { grid-column: span 9; }
.col-10 { grid-column: span 10; }
.col-12 { grid-column: span 12; }

.section { padding-block: var(--section-y); }
.section-lg { padding-block: var(--section-y-lg); }

.split {
  display: grid;
  grid-template-columns: minmax(0, 8fr) minmax(0, 3.4fr);
  gap: var(--space-6) var(--space-4);
}
.split-aside {
  font-size: var(--text-sm);
  line-height: 1.72;
  color: var(--color-ink-soft);
}

.prose { max-width: var(--measure); }
.prose p { margin: 0 0 var(--space-3); }
.prose h2 {
  font-size: var(--text-xl);
  margin: var(--space-6) 0 var(--space-2);
}
.prose h3 {
  font-size: var(--text-lg);
  margin: var(--space-4) 0 var(--space-2);
}
.prose a {
  color: var(--color-primary);
  text-decoration: none;
  background-image: linear-gradient(currentColor, currentColor);
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0 1px;
  transition: background-size 160ms linear;
}
.prose a:hover { background-size: 100% 1px; }
.prose ul, .prose ol { margin: 0 0 var(--space-3); }
.prose blockquote {
  margin: var(--space-4) 0;
  padding-left: var(--space-3);
  border-left: 3px solid var(--color-primary);
  color: var(--color-ink-soft);
  font-style: normal;
}

.lede {
  font-size: var(--text-lg);
  line-height: 1.72;
  color: var(--color-ink-soft);
  max-width: var(--measure);
}

/* ============================================================
   4. 印刷标签 / 标题 / 编号
   ============================================================ */
.label,
.kicker {
  display: inline-block;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 600;
  line-height: 1;
  letter-spacing: 0.16em;
  padding: 5px 8px 6px;
  border-radius: var(--radius-sm);
  vertical-align: middle;
}
.label-soft {
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
  box-shadow: inset 0 0 0 var(--border-thin) color-mix(in srgb, var(--color-primary) 32%, transparent);
}

.display-title {
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: 1.06;
  letter-spacing: var(--tracking-heading);
  margin: 0 0 var(--space-3);
}

.section-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);
  margin: var(--space-2) 0 var(--space-3);
  grid-column: 1 / -1;
}

.figure-num {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-3xl);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--color-primary);
}

/* ============================================================
   5. 分隔语言：细双线 / 刻度尺
   ============================================================ */
.rule {
  position: relative;
  height: 0;
  margin: var(--space-6) 0;
  border-top: var(--border-thin) solid var(--color-line);
}
.rule::after {
  content: "";
  position: absolute;
  left: 0; right: 0; top: 3px;
  border-top: var(--border-thin) solid color-mix(in srgb, var(--color-line) 52%, transparent);
}

.ticks {
  --tick-color: var(--color-line);
  display: block;
  height: 12px;
  background-image: repeating-linear-gradient(
    to right,
    var(--tick-color) 0 1px,
    transparent 1px 28px
  );
  border-bottom: var(--border-thin) solid var(--tick-color);
}
.ticks-contrast { --tick-color: var(--color-contrast-line); }

/* ============================================================
   6. 索引 / 数据 / 表格 / 折叠
   ============================================================ */
.index-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--border-thin) solid var(--color-line);
}
.index-list li {
  display: grid;
  grid-template-columns: 44px minmax(0, 1fr) auto;
  gap: var(--space-2);
  align-items: baseline;
  margin: 0;
  padding: 12px 0;
  border-bottom: var(--border-thin) solid var(--color-line);
}
.index-list .index-num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  letter-spacing: 0.08em;
}
.index-list .index-meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}

.data-panel {
  background-color: var(--color-surface-alt);
  border-top: var(--border-thin) solid var(--color-line);
  border-bottom: var(--border-thin) solid var(--color-line);
  padding: var(--space-3);
}
.stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  min-width: 0;
}
.stat-value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--text-2xl);
  font-weight: 600;
  line-height: 1;
  color: var(--color-accent);
}
.stat-value--primary { color: var(--color-primary); }
.stat-label {
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
}

.score-strip {
  display: flex;
  gap: var(--space-2);
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding-bottom: var(--space-2);
  -webkit-overflow-scrolling: touch;
}
.score-card {
  scroll-snap-align: start;
  flex: 0 0 240px;
  background-color: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  padding: var(--space-3);
}
.score-card--current {
  background-color: var(--color-highlight);
  border-color: var(--color-accent);
}
.score-card .score-line {
  font-family: var(--font-mono);
  font-size: var(--text-xl);
  line-height: 1.1;
  color: var(--color-accent);
}
.score-card .score-meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
  letter-spacing: 0.08em;
}

.table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}
.table caption {
  text-align: left;
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-ink-muted);
  padding-bottom: 8px;
}
.table th,
.table td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: var(--border-thin) solid var(--color-line);
  vertical-align: baseline;
}
.table thead th {
  font-weight: 600;
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  color: var(--color-ink-soft);
}
.table tbody tr:nth-child(even) { background-color: var(--color-surface-deep); }
.table .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  text-align: right;
}

.fold {
  border-top: var(--border-thin) solid var(--color-line);
}
.fold:last-of-type { border-bottom: var(--border-thin) solid var(--color-line); }
.fold > summary {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  padding: 14px 0;
  font-size: var(--text-sm);
  font-weight: 600;
  cursor: pointer;
  list-style: none;
}
.fold > summary::-webkit-details-marker { display: none; }
.fold > summary::before {
  content: "＋";
  font-family: var(--font-mono);
  color: var(--color-primary);
  flex: 0 0 auto;
}
.fold[open] > summary::before { content: "－"; }
.fold-body {
  background-color: var(--color-surface-deep);
  padding: var(--space-3) var(--space-3) var(--space-3) var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
}

/* ============================================================
   7. 引文 / 旁注
   ============================================================ */
.pullquote {
  margin: var(--space-6) 0;
  padding: var(--space-2) 0 var(--space-2) var(--space-4);
  border-left: 3px solid var(--color-primary);
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  line-height: 1.5;
  color: var(--color-ink);
}

.sidenote {
  font-size: var(--text-sm);
  line-height: 1.72;
  color: var(--color-ink-soft);
  border-top: var(--border-thin) solid var(--color-line);
  padding-top: var(--space-2);
  margin-bottom: var(--space-3);
}
.sidenote-num {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  color: var(--color-primary);
  margin-bottom: 4px;
}

/* ============================================================
   8. 深墨反差区块
   ============================================================ */
.contrast-block {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding-block: var(--section-y);
}
.contrast-block h1,
.contrast-block h2,
.contrast-block h3,
.contrast-block h4 { color: var(--color-contrast-ink); }
.contrast-block .lede,
.contrast-block .sidenote,
.contrast-block .split-aside { color: color-mix(in srgb, var(--color-contrast-ink) 76%, transparent); }
.contrast-block a { color: var(--color-contrast-accent); }
.contrast-block .rule { border-top-color: var(--color-contrast-line); }
.contrast-block .rule::after { border-top-color: color-mix(in srgb, var(--color-contrast-line) 62%, transparent); }
.contrast-block .stat-value { color: var(--color-contrast-accent); }
.contrast-block .stat-label,
.contrast-block .index-list .index-num { color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent); }
.contrast-block .index-list,
.contrast-block .index-list li { border-color: var(--color-contrast-line); }

/* ============================================================
   9. 按钮
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 16px;
  border: var(--border-thin) solid transparent;
  border-radius: var(--radius-sm);
  background-color: transparent;
  color: var(--color-ink);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.05em;
  line-height: 1.2;
  text-decoration: none;
  cursor: pointer;
  transition: background-color 140ms linear, color 140ms linear, border-color 140ms linear;
}
.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border-color: var(--color-primary);
}
.btn-primary:hover {
  background-color: color-mix(in srgb, var(--color-primary) 84%, var(--color-contrast-surface));
  border-color: color-mix(in srgb, var(--color-primary) 84%, var(--color-contrast-surface));
}
.btn-line {
  background-color: transparent;
  border-color: var(--color-line);
  color: var(--color-ink);
}
.btn-line:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background-color: var(--color-primary-soft);
}
.btn-sm {
  padding: 8px 13px;
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
}

/* ============================================================
   10. 图文容器
   ============================================================ */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  margin: 0;
  overflow: hidden;
  background-color: var(--color-surface-deep);
  border-radius: var(--radius-sm);
}
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: var(--radius-sm);
}
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--3x4 { aspect-ratio: 3 / 4; }
.media-overlay {
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
}
.media-label {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: var(--space-2) var(--space-3);
  color: var(--color-contrast-ink);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
}
.media-caption {
  margin-top: 8px;
  font-size: var(--text-xs);
  line-height: 1.6;
  color: var(--color-ink-muted);
}

/* ============================================================
   11. 面包屑
   ============================================================ */
.breadcrumb {
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  margin-bottom: var(--space-2);
}
.breadcrumb ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0;
  margin: 0;
  padding: 0;
}
.breadcrumb li { margin: 0; }
.breadcrumb li + li::before {
  content: "／";
  margin: 0 6px;
  color: var(--color-line);
}
.breadcrumb a {
  text-decoration: none;
  color: var(--color-ink-soft);
  transition: color 140ms linear;
}
.breadcrumb a:hover { color: var(--color-primary); }
.breadcrumb [aria-current="page"] { color: var(--color-ink); }

/* ============================================================
   12. 跳过链接
   ============================================================ */
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: -120px;
  z-index: 200;
  padding: 10px 16px;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  font-size: var(--text-sm);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: top 140ms linear;
}
.skip-link:focus { top: var(--space-2); }

/* ============================================================
   13. 站点头部
   ============================================================ */
.site-header { display: block; }

.header-spacer { height: 60px; }

.header-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 80;
  background-color: transparent;
  border-bottom: var(--border-thin) solid transparent;
  transition: background-color 160ms linear, border-color 160ms linear;
}
.site-header[data-state="scrolled"] .header-bar {
  background-color: var(--color-surface);
  border-bottom-color: var(--color-line);
}

.header-inner {
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
  height: 60px;
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 2px;
  text-decoration: none;
  color: var(--color-ink);
  flex: 0 0 auto;
}
.brand-mark {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1.1;
  letter-spacing: var(--tracking-heading);
}
.brand-sub {
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.22em;
  color: var(--color-ink-muted);
}

.header-stamp {
  display: none;
  align-items: center;
  gap: 8px;
  margin: 0 0 0 var(--space-3);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
}
.stamp-tick {
  display: inline-block;
  width: 26px;
  height: 7px;
  background-image: repeating-linear-gradient(
    to right,
    var(--color-ink-muted) 0 1px,
    transparent 1px 6px
  );
  border-bottom: var(--border-thin) solid var(--color-ink-muted);
}
.stamp-text { white-space: nowrap; }

.header-actions {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex: 0 0 auto;
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 12px;
  background-color: transparent;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  cursor: pointer;
  transition: border-color 140ms linear, color 140ms linear, background-color 140ms linear;
}
.nav-toggle:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background-color: var(--color-primary-soft);
}
.nav-toggle-mark {
  position: relative;
  display: block;
  width: 14px;
  height: 2px;
  background-color: currentColor;
}
.nav-toggle-mark::before,
.nav-toggle-mark::after {
  content: "";
  position: absolute;
  left: 0;
  width: 14px;
  height: 2px;
  background-color: currentColor;
  transition: transform 140ms linear;
}
.nav-toggle-mark::before { top: -5px; }
.nav-toggle-mark::after { top: 5px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-mark { background-color: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-mark::before { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-mark::after { transform: translateY(-5px) rotate(-45deg); }

/* 阅读进度刻度 */
.read-ruler {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 4px;
  background-image: repeating-linear-gradient(
    to right,
    var(--color-line) 0 1px,
    transparent 1px 24px
  );
  opacity: 0;
  transition: opacity 160ms linear;
}
.site-header[data-state="scrolled"] .read-ruler { opacity: 1; }
.ruler-fill {
  display: block;
  height: 100%;
  width: 100%;
  transform-origin: left center;
  transform: scaleX(var(--progress, 0));
  background-color: var(--color-primary);
  transition: transform 120ms linear;
}
.ruler-value {
  position: absolute;
  right: var(--gutter);
  top: -18px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--color-ink-muted);
}

/* 桌面竖排栏目轨道 */
.nav-rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 72px;
  z-index: 70;
  display: none;
  flex-direction: column;
  align-items: center;
  padding: var(--space-4) 8px;
  border-right: var(--border-thin) solid var(--color-line);
  background-color: transparent;
  transition: background-color 160ms linear;
}
.site-header[data-state="scrolled"] .nav-rail { background-color: var(--color-surface); }

.rail-title {
  width: 100%;
  padding-bottom: var(--space-3);
  margin-bottom: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
  text-align: center;
  font-size: 10px;
  letter-spacing: 0.32em;
  color: var(--color-ink-muted);
}
.rail-list {
  list-style: none;
  margin: 0;
  padding: 0;
  width: 100%;
}
.rail-list li { margin: 0; }
.rail-link {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  padding: 11px 2px;
  border-top: var(--border-thin) solid var(--color-line);
  text-decoration: none;
  color: var(--color-ink-soft);
  font-size: 12.5px;
  line-height: 1.24;
  letter-spacing: 0.05em;
  transition: background-color 140ms linear, color 140ms linear, border-color 140ms linear;
}
.rail-link .rail-num {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}
.rail-link:hover {
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
  border-top-color: var(--color-primary);
}
.rail-link:hover .rail-num { color: var(--color-primary); }
.rail-link[aria-current="page"] {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border-top-color: var(--color-primary);
}
.rail-link[aria-current="page"] .rail-num { color: var(--color-primary-ink); }

/* 移动底部快捷栏 */
.mobile-dock {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 85;
  background-color: var(--color-surface);
  border-top: var(--border-thin) solid var(--color-line);
}
.dock-nav {
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}
.dock-list {
  display: flex;
  margin: 0;
  padding: 0;
  list-style: none;
}
.dock-list li {
  flex: 0 0 auto;
  margin: 0;
  scroll-snap-align: start;
  border-right: var(--border-thin) solid var(--color-line);
}
.dock-link {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 9px 14px;
  text-decoration: none;
  color: var(--color-ink-soft);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  white-space: nowrap;
  transition: background-color 140ms linear, color 140ms linear;
}
.dock-link .dock-num {
  font-family: var(--font-mono);
  font-size: 9px;
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}
.dock-link[aria-current="page"] {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.dock-link[aria-current="page"] .dock-num { color: var(--color-primary-ink); }

.dock-extra {
  display: none;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--gutter);
  border-top: var(--border-thin) solid var(--color-line);
  background-color: var(--color-surface-alt);
}
.mobile-dock[data-open] .dock-extra { display: flex; }
.dock-stamp {
  margin: 0;
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
}

/* ============================================================
   14. 站点页脚
   ============================================================ */
.site-footer {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.footer-inner {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding: var(--section-y) var(--gutter) var(--space-4);
}
.footer-top {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}
.footer-brand-mark {
  margin: 0 0 8px;
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: 1.15;
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}
.footer-brand-sub {
  margin: 0 0 6px;
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 76%, transparent);
}
.footer-stamp {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.22em;
  color: var(--color-contrast-accent);
}
.footer-index {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
}
.footer-col-title {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin: 0 0 var(--space-2);
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid var(--color-contrast-line);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--color-contrast-ink);
}
.col-num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-contrast-accent);
}
.footer-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 8px;
  font-size: var(--text-sm);
}
.footer-list li { margin: 0; }
.footer-list a {
  text-decoration: none;
  color: color-mix(in srgb, var(--color-contrast-ink) 84%, transparent);
  background-image: linear-gradient(currentColor, currentColor);
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0 1px;
  transition: background-size 160ms linear, color 140ms linear;
}
.footer-list a:hover {
  color: var(--color-contrast-accent);
  background-size: 100% 1px;
}
.footer-contact li {
  color: color-mix(in srgb, var(--color-contrast-ink) 84%, transparent);
  line-height: 1.6;
}
.footer-contact .mono { letter-spacing: 0.02em; }

.footer-notice {
  max-width: var(--measure);
  margin: var(--space-6) 0 0;
  padding: var(--space-2) 0 var(--space-2) var(--space-3);
  border-left: 3px solid var(--color-primary);
  font-size: var(--text-sm);
  line-height: 1.72;
  color: color-mix(in srgb, var(--color-contrast-ink) 80%, transparent);
}

.footer-base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-3);
  margin-top: var(--space-6);
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-contrast-line);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 68%, transparent);
}
.footer-copy, .footer-icp { margin: 0; }
.footer-icp { font-family: var(--font-mono); letter-spacing: 0.06em; }
.footer-legal {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin: 0;
  padding: 0;
}
.footer-legal li { margin: 0; }
.footer-legal a {
  text-decoration: none;
  transition: color 140ms linear;
}
.footer-legal a:hover { color: var(--color-contrast-accent); }

/* ============================================================
   15. 响应式
   ============================================================ */
@media (min-width: 600px) {
  .footer-index { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .header-stamp { display: flex; }
}

@media (min-width: 900px) {
  body {
    padding-left: 72px;
    padding-bottom: 0;
  }
  .nav-rail { display: flex; }
  .header-bar { left: 72px; }
  .header-inner { height: 68px; }
  .header-spacer { height: 68px; }
  .mobile-dock { display: none; }
  .nav-toggle { display: none; }
  .header-stamp { margin-left: var(--space-4); }
  .footer-top { grid-template-columns: minmax(0, 280px) minmax(0, 1fr); gap: var(--space-8); }
  .footer-index { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .footer-legal { margin-left: auto; }
}

@media (max-width: 899px) {
  .grid > [class*="col-"] { grid-column: 1 / -1; }
  .split {
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-4);
  }
  .media-frame--16x9 { aspect-ratio: 16 / 10; }
}

@media (max-width: 599px) {
  h1 { font-size: calc(var(--text-2xl) * 0.94); }
  h2 { font-size: var(--text-xl); }
  h3 { font-size: var(--text-lg); }
  .section-title { font-size: var(--text-xl); }
  .figure-num { font-size: var(--text-2xl); }
  .brand-mark { font-size: var(--text-base); }
  .header-stamp { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .ruler-fill { transition: none; }
}