:root {
  --color-surface: #f9f9f9;
  --color-surface-alt: #f0f0f1;
  --color-surface-deep: #e4e4e5;
  --color-ink: #474852;
  --color-ink-soft: #6c6d7a;
  --color-ink-muted: #797a86;
  --color-line: #d9d9db;
  --color-primary: #3a47c5;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #dee0f2;
  --color-accent: #ae6128;
  --color-accent-ink: #ffffff;
  --color-highlight: #ecded3;
  --color-focus: #ab591c;
  --color-contrast-surface: #181928;
  --color-contrast-ink: #e4e4e7;
  --color-contrast-line: #454652;
  --color-contrast-accent: #cf7430;
  --overlay-scrim: linear-gradient(180deg, rgba(24, 25, 40, 0.35) 0%, rgba(24, 25, 40, 0.72) 55%, rgba(24, 25, 40, 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: 12.2px;
  --text-sm: 15.2px;
  --text-base: 17px;
  --text-lg: 21.2px;
  --text-xl: 26.6px;
  --text-2xl: 33.2px;
  --text-3xl: 41.5px;
  --text-4xl: 51.9px;
  --text-display: clamp(34px, 4.2vw, 54px);
  --text-figure: clamp(28px, 3.0vw, 39px);
  --weight-heading: 698;
  --weight-body: 400;
  --leading-body: 1.67;
  --leading-heading: 1.28;
  --tracking-heading: -0.007em;
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-pill: 999px;
  --border-thin: 1px;
  --border-thick: 1px;
  --shadow-1: 0 1px 0 rgba(71, 72, 82, 0.12);
  --shadow-2: 0 2px 0 rgba(71, 72, 82, 0.18);
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-6: 48px;
  --space-8: 64px;
  --container: 1260px;
  --measure: 69ch;
  --gutter: 24px;
  --section-y: 77px;
  --section-y-lg: 108px;
}

/* ============ 01 RESET ============ */
*, *::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);
  line-height: var(--leading-body);
  font-weight: var(--weight-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
img, svg, video, canvas { display: block; max-width: 100%; height: auto; }
h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd, hr { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
button, input, select, textarea { font: inherit; color: inherit; }
table { border-collapse: collapse; border-spacing: 0; }
a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 2px; }
main { display: block; }

/* ============ 02 中文排版 ============ */
h1, h2, h3, h4 {
  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-display); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }
strong, b { font-weight: var(--weight-heading); }
code, kbd, samp, .mono { font-family: var(--font-mono); font-size: .92em; }

.u-visually-hidden {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); clip-path: inset(50%); white-space: nowrap; border: 0;
}

/* ============ 03 布局骨架 ============ */
.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-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-3);
  padding-bottom: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
  margin-bottom: var(--space-4);
}
.rule { height: 0; border: 0; border-top: var(--border-thin) solid var(--color-line); }
.grid { display: grid; gap: var(--gutter); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}
.eyebrow::before { content: ""; width: 18px; height: var(--border-thin); background-color: var(--color-accent); }
.lede { font-size: var(--text-lg); line-height: 1.5; color: var(--color-ink-soft); }

.prose { max-width: var(--measure); }
.prose p { margin-bottom: var(--space-2); }
.prose h2 { margin: var(--space-6) 0 var(--space-2); }
.prose h3 { margin: var(--space-4) 0 var(--space-1); }
.prose ul { margin: var(--space-2) 0; }
.prose ul > li { position: relative; padding-left: var(--space-3); margin-bottom: 10px; }
.prose ul > li::before {
  content: ""; position: absolute; left: 0; top: .78em;
  width: 12px; height: var(--border-thin); background-color: var(--color-accent);
}
.prose a { text-decoration: underline; text-underline-offset: 3px; }
.prose blockquote {
  border-left: 3px solid var(--color-primary);
  padding: var(--space-1) 0 var(--space-1) var(--space-3);
  color: var(--color-ink-soft);
}

/* ============ 04 通用按钮 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: 11px var(--space-3);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  color: var(--color-ink);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: .02em;
  cursor: pointer;
  text-decoration: none;
  transition: background-color .18s ease, color .18s ease, border-color .18s ease;
}
.btn:hover { text-decoration: none; }
.btn:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 2px; }
.btn--primary { background-color: var(--color-primary); border-color: var(--color-primary); color: var(--color-primary-ink); }
.btn--primary:hover { background-color: color-mix(in srgb, var(--color-primary) 86%, var(--color-contrast-surface)); border-color: color-mix(in srgb, var(--color-primary) 86%, var(--color-contrast-surface)); color: var(--color-primary-ink); }
.btn--accent { background-color: var(--color-accent); border-color: var(--color-accent); color: var(--color-accent-ink); }
.btn--accent:hover { background-color: color-mix(in srgb, var(--color-accent) 86%, var(--color-contrast-surface)); border-color: color-mix(in srgb, var(--color-accent) 86%, var(--color-contrast-surface)); color: var(--color-accent-ink); }
.btn--ghost { background-color: transparent; border-color: var(--color-line); color: var(--color-ink); }
.btn--ghost:hover { background-color: var(--color-primary-soft); border-color: var(--color-primary); color: var(--color-primary); }

/* ============ 05 头部：移动端顶部条 + 抽屉 ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-bottom: var(--border-thin) solid var(--color-contrast-line);
}
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: calc(-1 * var(--space-8));
  z-index: 320;
  padding: 10px var(--space-2);
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  text-decoration: none;
  transition: top .16s ease;
}
.skip-link:focus { top: var(--space-2); text-decoration: none; }

.scroll-progress {
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 3px;
  z-index: 20;
  pointer-events: none;
  background-color: color-mix(in srgb, var(--color-contrast-ink) 14%, transparent);
}
.scroll-progress-fill {
  display: block;
  height: 100%;
  width: var(--progress, 0%);
  background-color: var(--color-accent);
  transition: width .1s linear;
}

.rail-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  min-height: 64px;
  padding: var(--space-2) var(--gutter);
}
.rail-brand { display: flex; flex-direction: column; gap: 2px; text-decoration: none; }
.rail-brand:hover { text-decoration: none; }
.rail-mark {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: 1.12;
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}
.rail-brand:hover .rail-mark { color: var(--color-contrast-accent); }
.rail-note {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .04em;
  color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent);
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 9px 12px;
  border: var(--border-thin) solid var(--color-contrast-line);
  border-radius: var(--radius-sm);
  background-color: transparent;
  color: var(--color-contrast-ink);
  font-size: var(--text-xs);
  letter-spacing: .12em;
  cursor: pointer;
}
.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: 4px; width: 16px; height: 14px; }
.nav-toggle-bar {
  display: block; height: 2px; width: 100%;
  background-color: currentColor;
  transition: transform .18s ease, opacity .18s ease;
}
.nav-toggle-text { font-family: var(--font-mono); }
.site-header[data-open] .nav-toggle-bar:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.site-header[data-open] .nav-toggle-bar:nth-child(2) { opacity: 0; }
.site-header[data-open] .nav-toggle-bar:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.rail-nav {
  max-height: 0;
  overflow: hidden;
  visibility: hidden;
  border-top: 0 solid var(--color-contrast-line);
  transition: max-height .3s ease, visibility .3s ease;
}
.site-header[data-open] .rail-nav {
  max-height: 74vh;
  overflow-y: auto;
  overscroll-behavior: contain;
  visibility: visible;
  border-top-width: var(--border-thin);
}
.rail-nav-label {
  padding: var(--space-2) var(--gutter) var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .16em;
  color: color-mix(in srgb, var(--color-contrast-ink) 55%, transparent);
}
.rail-nav-list { display: flex; flex-direction: column; padding-bottom: var(--space-2); }
.rail-nav-item { display: block; }
.rail-link {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  align-items: center;
  gap: var(--space-2);
  padding: 13px var(--gutter);
  border-left: 3px solid transparent;
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  text-decoration: none;
  transition: background-color .18s ease, color .18s ease, border-color .18s ease;
}
.rail-link:hover {
  background-color: color-mix(in srgb, var(--color-contrast-ink) 9%, transparent);
  color: var(--color-contrast-ink);
  text-decoration: none;
}
.rail-num {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .08em;
  color: var(--color-contrast-accent);
  text-align: right;
}
.rail-label { letter-spacing: .02em; }
.rail-link[aria-current="page"] {
  background-color: var(--color-primary);
  border-left-color: var(--color-contrast-accent);
  color: var(--color-primary-ink);
}
.rail-link[aria-current="page"] .rail-num { color: var(--color-primary-ink); }
.rail-link[aria-current="page"]:hover { background-color: color-mix(in srgb, var(--color-primary) 88%, var(--color-primary-ink)); }

.rail-meter { display: none; }
.rail-foot { display: none; }
.rail-foot-note {
  margin-top: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .06em;
  color: color-mix(in srgb, var(--color-contrast-ink) 48%, transparent);
}
.btn--rail {
  width: 100%;
  background-color: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.btn--rail:hover {
  background-color: color-mix(in srgb, var(--color-primary) 84%, var(--color-primary-ink));
  border-color: color-mix(in srgb, var(--color-primary) 84%, var(--color-primary-ink));
  color: var(--color-primary-ink);
}

/* ============ 06 页脚：线框 + 刻度收口 ============ */
.site-footer {
  margin-top: var(--section-y-lg);
  background-color: var(--color-surface-alt);
  color: var(--color-ink);
  border-top: var(--border-thin) solid var(--color-line);
}
.footer-ruler {
  height: 14px;
  border-bottom: var(--border-thin) solid var(--color-line);
  background-image: repeating-linear-gradient(
    to right,
    var(--color-line) 0 1px,
    transparent 1px var(--gutter)
  );
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.2fr;
  gap: var(--gutter);
  padding-block: var(--section-y) var(--space-6);
}
.footer-brand { display: flex; flex-direction: column; gap: 2px; }
.footer-mark {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}
.footer-note { margin-top: var(--space-1); font-size: var(--text-sm); color: var(--color-ink-soft); }
.footer-meta {
  margin-top: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .08em;
  color: var(--color-ink-muted);
}
.footer-col {
  border-left: var(--border-thin) solid var(--color-line);
  padding-left: var(--space-3);
}
.footer-col-title {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--weight-body);
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
  padding-bottom: var(--space-1);
  margin-bottom: var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.footer-list { display: flex; flex-direction: column; gap: 10px; }
.footer-list--plain { gap: 14px; }
.footer-list a {
  color: var(--color-ink);
  font-size: var(--text-sm);
  text-decoration: none;
}
.footer-list a:hover { color: var(--color-primary); text-decoration: underline; text-underline-offset: 3px; }
.footer-contact { display: flex; align-items: center; flex-wrap: wrap; gap: var(--space-1); }
.footer-contact-val { font-family: var(--font-mono); font-size: var(--text-sm); color: var(--color-ink); }
.footer-addr { font-size: var(--text-sm); line-height: 1.5; color: var(--color-ink-soft); }
.copy-btn {
  padding: 3px 8px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface);
  color: var(--color-ink-muted);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .06em;
  cursor: pointer;
  transition: color .16s ease, border-color .16s ease, background-color .16s ease;
}
.copy-btn:hover { color: var(--color-primary); border-color: var(--color-primary); }
.copy-btn[data-copied] {
  background-color: var(--color-primary-soft);
  border-color: var(--color-primary);
  color: var(--color-primary);
}
.footer-legal {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}
.footer-legal-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2) var(--space-3);
  padding-block: var(--space-2);
}
.footer-legal-item {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .08em;
  color: color-mix(in srgb, var(--color-contrast-ink) 78%, transparent);
}
.footer-legal-item--end { color: color-mix(in srgb, var(--color-contrast-ink) 52%, transparent); }

/* ============ 07 通用组件 ============ */
.panel {
  background-color: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  padding: var(--space-3);
}
.panel--alt { background-color: var(--color-surface-alt); border-color: var(--color-surface-deep); }
.panel--deep {
  background-color: var(--color-contrast-surface);
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.panel--deep h2, .panel--deep h3, .panel--deep h4, .panel--deep .stat-value { color: var(--color-contrast-ink); }
.panel--deep .stat-label, .panel--deep .eyebrow { color: color-mix(in srgb, var(--color-contrast-ink) 62%, transparent); }
.panel--accent { border-left: 3px solid var(--color-accent); }

.stat { display: flex; flex-direction: column; gap: 4px; }
.stat-value {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 600;
  line-height: 1.04;
  letter-spacing: -0.01em;
  color: var(--color-primary);
}
.stat-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .12em;
  color: var(--color-ink-muted);
}

.index-list { display: flex; flex-direction: column; border-top: var(--border-thin) solid var(--color-line); }
.index-list > li { border-bottom: var(--border-thin) solid var(--color-line); }
.index-item {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr);
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-1);
  color: var(--color-ink);
  text-decoration: none;
  transition: background-color .18s ease;
}
.index-item:hover { background-color: var(--color-primary-soft); text-decoration: none; }
.index-num {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--color-accent);
  text-align: right;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-sm);
  background-color: var(--color-surface-alt);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .06em;
  color: var(--color-ink-soft);
}
.tag--primary {
  background-color: var(--color-primary-soft);
  border-color: color-mix(in srgb, var(--color-primary) 32%, var(--color-line));
  color: var(--color-primary);
}
.tag--accent {
  background-color: var(--color-highlight);
  border-color: color-mix(in srgb, var(--color-accent) 42%, var(--color-line));
  color: var(--color-accent);
}
.tag--live::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: var(--radius-pill);
  background-color: var(--color-accent);
}

.data-table { width: 100%; font-size: var(--text-sm); }
.data-table caption {
  text-align: left;
  padding-bottom: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .12em;
  color: var(--color-ink-muted);
}
.data-table th, .data-table td {
  padding: 11px var(--space-2);
  border-bottom: var(--border-thin) solid var(--color-line);
  text-align: left;
  vertical-align: top;
}
.data-table th {
  background-color: var(--color-surface-alt);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--weight-body);
  letter-spacing: .1em;
  color: var(--color-ink-muted);
  white-space: nowrap;
}
.data-table td.num { font-family: var(--font-mono); text-align: right; white-space: nowrap; }
.data-table tbody tr:hover { background-color: var(--color-primary-soft); }

.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: .08em;
  color: var(--color-ink-muted);
}
.crumbs li { display: flex; align-items: center; gap: var(--space-1); }
.crumbs li + li::before { content: "/"; color: var(--color-line); }
.crumbs a { color: var(--color-ink-soft); }
.crumbs a:hover { color: var(--color-primary); }
.crumbs [aria-current="page"] { color: var(--color-ink); }

.disclosure { border-bottom: var(--border-thin) solid var(--color-line); }
.disclosure-btn {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  width: 100%;
  padding: var(--space-2) 0;
  background-color: transparent;
  border: 0;
  text-align: left;
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  font-size: var(--text-lg);
  line-height: var(--leading-heading);
  color: var(--color-ink);
  cursor: pointer;
}
.disclosure-btn::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  line-height: 1;
  color: var(--color-accent);
  transition: transform .2s ease;
}
.disclosure-btn[aria-expanded="true"]::after { transform: rotate(45deg); }
.disclosure-panel { padding: 0 0 var(--space-3); font-size: var(--text-sm); color: var(--color-ink-soft); }
.disclosure-panel[hidden] { display: none; }

/* ============ 08 媒体容器（叠色 / 单色调 / scrim） ============ */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-md);
  background-color: var(--color-contrast-surface);
}
.media-frame > img, .media-frame > video { width: 100%; height: 100%; object-fit: cover; }
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--21x9 { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--tint > img { filter: grayscale(1) contrast(1.08); }
.media-frame--tint::after {
  content: "";
  position: absolute;
  inset: 0;
  background-color: var(--color-primary);
  opacity: .34;
  mix-blend-mode: multiply;
  pointer-events: none;
}
.media-frame--overlay::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
}
.media-caption {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  z-index: 2;
  padding: var(--space-3);
  color: var(--color-contrast-ink);
  font-size: var(--text-sm);
  line-height: 1.5;
}

/* ============ 09 滚动显现 ============ */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .5s ease, transform .5s ease;
}
html.js [data-reveal].is-visible { opacity: 1; transform: none; }

/* ============ 10 平板 ============ */
@media (max-width: 1023px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
  .footer-col { border-left: 0; padding-left: 0; padding-top: var(--space-3); border-top: var(--border-thin) solid var(--color-line); }
  .grid--4, .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
}

/* ============ 11 桌面：左侧固定导览轨道 ============ */
@media (min-width: 1024px) {
  body { padding-left: 248px; }

  .site-header {
    position: fixed;
    top: 0; left: 0; bottom: 0;
    width: 248px;
    display: flex;
    flex-direction: column;
    border-bottom: 0;
    border-right: var(--border-thin) solid var(--color-contrast-line);
    overflow-y: auto;
    overscroll-behavior: contain;
  }
  .scroll-progress {
    position: fixed;
    top: 0; bottom: 0; left: auto; right: 0;
    width: 3px; height: auto;
    z-index: 130;
    background-color: color-mix(in srgb, var(--color-contrast-surface) 14%, transparent);
  }
  .scroll-progress-fill { width: 100%; height: var(--progress, 0%); transition: height .1s linear; }

  .rail-top {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-1);
    min-height: 0;
    padding: var(--space-3) var(--space-3) var(--space-2);
  }
  .rail-mark { font-size: var(--text-xl); }
  .nav-toggle { display: none; }

  .site-header .rail-nav,
  .site-header[data-open] .rail-nav {
    max-height: none;
    overflow: visible;
    visibility: visible;
    border-top: var(--border-thin) solid var(--color-contrast-line);
    margin-top: var(--space-2);
  }
  .rail-nav-label { padding: var(--space-2) var(--space-3) var(--space-1); }
  .rail-nav-list { padding-bottom: var(--space-2); }
  .rail-link {
    grid-template-columns: 26px minmax(0, 1fr);
    gap: var(--space-1);
    padding: 12px var(--space-3);
  }
  .rail-meter {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 4px var(--space-2);
    padding: var(--space-2) var(--space-3) var(--space-3);
    border-top: var(--border-thin) solid var(--color-contrast-line);
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    letter-spacing: .1em;
    color: color-mix(in srgb, var(--color-contrast-ink) 56%, transparent);
  }
  .rail-meter-key { text-transform: uppercase; }
  .rail-meter-val { color: var(--color-contrast-ink); text-align: right; }

  .rail-foot {
    display: block;
    margin-top: auto;
    padding: var(--space-3);
    border-top: var(--border-thin) solid var(--color-contrast-line);
  }
  .grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
}

/* ============ 12 手机 ============ */
@media (max-width: 620px) {
  .grid--2, .grid--3, .grid--4 { grid-template-columns: minmax(0, 1fr); }
  .grid--12 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .index-item { grid-template-columns: 56px minmax(0, 1fr); }
  .section-head { flex-direction: column; align-items: flex-start; }
  .data-table th, .data-table td { padding: 9px 10px; }
}

/* ============ 13 降低动效 ============ */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  html.js [data-reveal] { opacity: 1; transform: none; }
}