:root {
  --color-surface: #f8f8f8;
  --color-surface-alt: #eeeeee;
  --color-surface-deep: #e1e0e0;
  --color-ink: #363031;
  --color-ink-soft: #665c5d;
  --color-ink-muted: #827879;
  --color-line: #d5d4d4;
  --color-primary: #e8122e;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #f6d8dc;
  --color-accent: #e80d2a;
  --color-accent-ink: #ffffff;
  --color-highlight: #f5ced3;
  --color-focus: #e0001e;
  --color-contrast-surface: #281215;
  --color-contrast-ink: #e7e4e5;
  --color-contrast-line: #524043;
  --color-contrast-accent: #f42f49;
  --overlay-scrim: linear-gradient(180deg, rgba(40, 18, 21, 0.35) 0%, rgba(40, 18, 21, 0.72) 55%, rgba(40, 18, 21, 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: 11.0px;
  --text-sm: 14.7px;
  --text-base: 17px;
  --text-lg: 22.7px;
  --text-xl: 30.2px;
  --text-2xl: 40.3px;
  --text-3xl: 53.7px;
  --text-4xl: 71.5px;
  --text-display: clamp(43px, 8.8vw, 113px);
  --text-figure: clamp(36px, 6.3vw, 81px);
  --weight-heading: 800;
  --weight-body: 400;
  --leading-body: 1.76;
  --leading-heading: 1.26;
  --tracking-heading: -0.01em;
  --radius-sm: 0px;
  --radius-md: 0px;
  --radius-lg: 0px;
  --radius-pill: 0px;
  --border-thin: 1px;
  --border-thick: 3px;
  --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: 1140px;
  --measure: 66ch;
  --gutter: 16px;
  --section-y: 86px;
  --section-y-lg: 120px;
}

/* ============================================================
   0. Reset
   ============================================================ */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  --rail: 240px;
  --header-h: 64px;
  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);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
}

p { margin: 0 0 var(--space-2); }

ul, ol { margin: 0; padding: 0; list-style: none; }

a { color: inherit; text-decoration: none; }

img, svg, video { display: block; max-width: 100%; height: auto; }

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

table { border-collapse: collapse; width: 100%; }

hr {
  border: 0;
  border-top: var(--border-thin) solid var(--color-line);
  margin: 0;
}

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

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

/* ============================================================
   1. 跳转链接
   ============================================================ */
.skip-link {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 200;
  transform: translateY(-140%);
  padding: var(--space-2) var(--space-3);
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  transition: transform 160ms linear;
}

.skip-link:focus {
  transform: translateY(0);
}

/* ============================================================
   2. 头部（移动端为顶栏 + 抽屉，桌面端为 240px 固定侧轨）
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
}

.site-header__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  min-width: 0;
}

.brand__mark {
  flex: none;
  width: 12px;
  height: 12px;
  background-color: var(--color-primary);
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.brand__name {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: 1.1;
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}

.brand__sub {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: color-mix(in srgb, var(--color-contrast-ink) 56%, transparent);
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  flex: none;
  padding: var(--space-1) var(--space-2);
  border: var(--border-thin) solid var(--color-contrast-line);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  transition: background-color 160ms linear, border-color 160ms linear, color 160ms linear;
}

.nav-toggle:hover {
  border-color: var(--color-contrast-accent);
  color: var(--color-contrast-accent);
}

.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 3px;
  width: 14px;
}

.nav-toggle__bars span {
  display: block;
  height: 2px;
  background-color: currentColor;
}

.nav-toggle__text { line-height: 1; }

.nav-toggle[aria-expanded="true"] {
  background-color: var(--color-contrast-accent);
  border-color: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
}

.site-nav {
  display: none;
  background-color: var(--color-contrast-surface);
}

.site-nav[data-open] {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-height: calc(100dvh - var(--header-h));
  overflow-y: auto;
  padding: var(--space-2) var(--space-3) var(--space-4);
}

.site-nav__list {
  display: flex;
  flex-direction: column;
}

.site-nav__list li {
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.site-nav__list li:last-child {
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
}

.site-nav__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  padding: var(--space-2) 0;
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-contrast-ink);
  transition: color 160ms linear, background-color 160ms linear;
}

.site-nav__link:hover { color: var(--color-contrast-accent); }

.site-nav__index {
  flex: none;
  width: 2.4ch;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.06em;
  color: color-mix(in srgb, var(--color-contrast-ink) 48%, transparent);
}

.site-nav__link[aria-current="page"] {
  color: var(--color-contrast-accent);
}

.site-nav__link[aria-current="page"] .site-nav__index {
  color: var(--color-contrast-accent);
}

.rail-group {
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.rail-group__title {
  margin: 0 0 var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: color-mix(in srgb, var(--color-contrast-ink) 52%, transparent);
}

.rail-group__list {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
}

.rail-group__list a {
  display: block;
  padding: 3px var(--space-1);
  border: var(--border-thin) solid var(--color-contrast-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-contrast-ink);
  transition: background-color 160ms linear, border-color 160ms linear, color 160ms linear;
}

.rail-group__list a:hover {
  background-color: var(--color-contrast-accent);
  border-color: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
}

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

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

.section + .section {
  border-top: var(--border-thin) solid var(--color-line);
}

.section + .section--contrast,
.section--contrast + .section {
  border-top: 0;
}

.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 .section__lede,
.section--contrast .prose,
.section--contrast .prose p {
  color: var(--color-contrast-ink);
}

.section--contrast .eyebrow,
.section--contrast .figure__label {
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}

.section--tight { padding-block: var(--space-6); }

.section__head {
  display: grid;
  gap: var(--space-2);
  max-width: var(--measure);
  margin-bottom: var(--space-6);
}

.eyebrow {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.eyebrow::before {
  content: "";
  display: block;
  width: 24px;
  height: 2px;
  flex: none;
  background-color: var(--color-primary);
}

.section__title {
  font-size: clamp(var(--text-xl), 4vw, var(--text-3xl));
  font-weight: var(--weight-heading);
}

.section__lede {
  max-width: var(--measure);
  margin: 0;
  color: var(--color-ink-soft);
}

.display-title {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-display);
  line-height: 1.02;
  letter-spacing: -0.03em;
  text-transform: uppercase;
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--gutter);
}

.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: span 12; }

/* ============================================================
   4. 面包屑
   ============================================================ */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  padding-block: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

.breadcrumb a:hover { color: var(--color-primary); }

.breadcrumb__sep {
  color: var(--color-line);
  padding-inline: 2px;
}

/* ============================================================
   5. 按钮与筛选
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  border: var(--border-thin) solid var(--color-line);
  background-color: var(--color-surface);
  color: var(--color-ink);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  transition: background-color 180ms linear, color 180ms linear, border-color 180ms linear;
}

.btn:hover {
  background-color: var(--color-contrast-surface);
  border-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.btn--primary {
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.btn--primary:hover {
  background-color: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}

.btn--ghost {
  background-color: transparent;
  border-color: currentColor;
}

.btn--ghost:hover {
  background-color: var(--color-surface-alt);
  border-color: var(--color-ink);
  color: var(--color-ink);
}

.btn--block {
  width: 100%;
  justify-content: space-between;
}

.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px var(--space-2);
  border: var(--border-thin) solid var(--color-line);
  background-color: var(--color-surface);
  color: var(--color-ink-soft);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.04em;
  transition: background-color 160ms linear, border-color 160ms linear, color 160ms linear;
}

.chip:hover {
  border-color: var(--color-ink-muted);
  color: var(--color-ink);
}

.chip[aria-pressed="true"],
.chip[data-active] {
  background-color: var(--color-highlight);
  border-color: var(--color-focus);
  color: var(--color-ink);
}

/* ============================================================
   6. 数据表
   ============================================================ */
.data-table {
  border-top: var(--border-thick) solid var(--color-primary);
  font-size: var(--text-sm);
}

.data-table caption {
  padding-bottom: var(--space-2);
  text-align: left;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.data-table th {
  padding: var(--space-1) var(--space-2);
  background-color: var(--color-surface-deep);
  border-bottom: var(--border-thin) solid var(--color-line);
  text-align: left;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-ink-soft);
}

.data-table td {
  padding: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
  vertical-align: baseline;
}

.data-table td:first-child { position: relative; }

.data-table tbody tr { transition: background-color 160ms linear; }

.data-table tbody tr:hover { background-color: var(--color-highlight); }

.data-table tbody tr:hover td:first-child::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background-color: var(--color-primary);
}

/* ============================================================
   7. 数字与标记
   ============================================================ */
.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
}

.figure {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.figure__value {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: var(--weight-heading);
  line-height: 0.94;
  letter-spacing: -0.035em;
  font-variant-numeric: tabular-nums;
  color: var(--color-primary);
}

.section--contrast .figure__value { color: var(--color-contrast-accent); }

.figure__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.mark {
  display: inline-block;
  padding: 2px 6px;
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.section--contrast .mark,
.panel--contrast .mark,
.footer-panel--contrast .mark {
  background-color: var(--color-contrast-ink);
  color: var(--color-contrast-surface);
}

/* ============================================================
   8. 关键数字带
   ============================================================ */
.stat-grid {
  display: grid;
  gap: var(--border-thin);
  background-color: var(--color-line);
  border: var(--border-thin) solid var(--color-line);
}

.stat-grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.stat {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3);
  background-color: var(--color-surface);
}

.section--contrast .stat-grid {
  background-color: var(--color-contrast-line);
  border-color: var(--color-contrast-line);
}

.section--contrast .stat {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

/* ============================================================
   9. 面板与图片容器
   ============================================================ */
.panel {
  padding: var(--space-4);
  border: var(--border-thin) solid var(--color-line);
  background-color: var(--color-surface);
}

.panel--contrast {
  background-color: var(--color-contrast-surface);
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}

.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background-color: var(--color-surface-deep);
  border: 0;
  border-radius: 0;
}

.media-frame img,
.media-frame svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame__overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: flex-end;
  padding: var(--space-3);
  background: var(--overlay-scrim);
  color: var(--color-contrast-ink);
}

.media-frame__caption {
  padding-top: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

/* ============================================================
   10. 长文
   ============================================================ */
.prose {
  max-width: var(--measure);
  color: var(--color-ink-soft);
}

.prose h2 {
  margin-block: var(--space-6) var(--space-2);
  font-size: clamp(var(--text-lg), 3vw, var(--text-xl));
  color: var(--color-ink);
}

.prose h3 {
  margin-block: var(--space-4) var(--space-2);
  font-size: var(--text-lg);
  color: var(--color-ink);
}

.prose p { margin-bottom: var(--space-3); }

.prose ul { margin-bottom: var(--space-3); }

.prose li {
  position: relative;
  margin-bottom: var(--space-1);
  padding-left: var(--space-3);
}

.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 8px;
  height: 2px;
  background-color: var(--color-primary);
}

.prose a {
  border-bottom: var(--border-thin) solid var(--color-primary);
  color: var(--color-ink);
}

.prose a:hover { color: var(--color-primary); }

/* ============================================================
   11. 可展开内容组
   ============================================================ */
.accordion {
  border-top: var(--border-thin) solid var(--color-line);
}

.accordion__item {
  border-bottom: var(--border-thin) solid var(--color-line);
}

.accordion__trigger {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-3) var(--space-2);
  text-align: left;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: 700;
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  transition: background-color 160ms linear, color 160ms linear;
}

.accordion__trigger:hover { background-color: var(--color-surface-alt); }

.accordion__item[data-open] > .accordion__trigger {
  background-color: var(--color-highlight);
}

.accordion__index {
  flex: none;
  width: 3ch;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

.accordion__label { flex: 1 1 auto; }

.accordion__icon {
  flex: none;
  align-self: center;
  width: 11px;
  height: 11px;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg);
  transition: transform 180ms linear;
}

.accordion__item[data-open] > .accordion__trigger .accordion__icon {
  transform: rotate(-135deg);
}

.accordion__panel {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 200ms linear;
}

.accordion__item[data-open] > .accordion__panel {
  grid-template-rows: 1fr;
}

.accordion__panel > div {
  min-height: 0;
  overflow: hidden;
}

.accordion__body {
  max-width: var(--measure);
  padding: 0 var(--space-2) var(--space-3);
  color: var(--color-ink-soft);
}

.accordion__body p:last-child { margin-bottom: 0; }

/* ============================================================
   12. 滚动进度条
   ============================================================ */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 120;
  height: 2px;
  width: 0;
  background-color: var(--color-primary);
  transition: width 80ms linear;
}

/* ============================================================
   13. 页脚
   ============================================================ */
.site-footer {
  background-color: var(--color-surface-alt);
  border-top: var(--border-thick) solid var(--color-contrast-surface);
  padding-block: var(--space-8) var(--space-4);
  color: var(--color-ink);
}

.footer-masthead {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-2);
  padding-bottom: var(--space-3);
  margin-bottom: var(--space-4);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.footer-masthead__brand {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.footer-masthead__brand:hover { color: var(--color-primary); }

.footer-masthead__sub {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: var(--border-thin);
  background-color: var(--color-line);
}

.footer-panel {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-3);
  background-color: var(--color-surface);
}

.footer-panel--alt { background-color: var(--color-surface-alt); }
.footer-panel--deep { background-color: var(--color-surface-deep); }

.footer-panel--contrast {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.footer-panel__title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

.footer-panel--contrast .footer-panel__title {
  color: var(--color-contrast-accent);
}

.footer-panel__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.footer-panel__list li {
  font-size: var(--text-sm);
  line-height: 1.6;
  color: var(--color-ink-soft);
  word-break: break-word;
}

.footer-panel--contrast .footer-panel__list li {
  color: var(--color-contrast-ink);
}

.footer-panel__list a {
  display: inline-block;
  border-bottom: var(--border-thin) solid transparent;
  color: var(--color-ink);
  transition: border-color 160ms linear, color 160ms linear;
}

.footer-panel__list a:hover {
  border-bottom-color: var(--color-primary);
  color: var(--color-primary);
}

.footer-panel--contrast .footer-panel__list a {
  color: var(--color-contrast-ink);
}

.footer-panel--contrast .footer-panel__list a:hover {
  border-bottom-color: var(--color-contrast-accent);
  color: var(--color-contrast-accent);
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-1) var(--space-4);
  padding-top: var(--space-3);
  margin-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-line);
}

.footer-legal__copy,
.footer-legal__note,
.footer-legal__icp {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}

/* ============================================================
   14. 断点：桌面侧轨
   ============================================================ */
@media (min-width: 1024px) {
  body {
    padding-left: var(--rail);
  }

  .site-header {
    position: fixed;
    inset: 0 auto 0 0;
    width: var(--rail);
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    border-bottom: 0;
    border-right: var(--border-thin) solid var(--color-contrast-line);
  }

  .site-header__bar {
    display: block;
    padding: var(--space-4) var(--space-4) var(--space-3);
  }

  .nav-toggle { display: none; }

  .site-nav,
  .site-nav[data-open] {
    display: flex;
    flex-direction: column;
    flex: 1 1 auto;
    gap: 0;
    max-height: none;
    overflow: visible;
    padding: var(--space-2) 0 var(--space-4);
  }

  .site-nav__link {
    padding: var(--space-2) var(--space-4);
  }

  .site-nav__link[aria-current="page"] {
    background-color: var(--color-contrast-accent);
    color: var(--color-contrast-surface);
  }

  .site-nav__link[aria-current="page"] .site-nav__index {
    color: var(--color-contrast-surface);
  }

  .rail-group {
    margin-top: auto;
    padding: var(--space-3) var(--space-4) 0;
  }

  .scroll-progress { left: var(--rail); }

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

/* ============================================================
   15. 断点：平板与手机
   ============================================================ */
@media (max-width: 1000px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 900px) {
  .col-4,
  .col-5,
  .col-7,
  .col-8 { grid-column: 1 / -1; }

  .stat-grid,
  .stat-grid--3 { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .footer-grid { grid-template-columns: 1fr; }
  .section { padding-block: var(--space-6); }
  .footer-legal { flex-direction: column; }
  .accordion__trigger { font-size: var(--text-base); }
}

/* ============================================================
   16. 降低动效
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
  }

  .accordion__panel { transition: none; }
  .scroll-progress { transition: none; }
}