:root {
  --color-surface: #fbfbfb;
  --color-surface-alt: #f1f1f1;
  --color-surface-deep: #e4e3e3;
  --color-ink: #393233;
  --color-ink-soft: #685e60;
  --color-ink-muted: #857a7c;
  --color-line: #d8d7d7;
  --color-primary: #e31c36;
  --color-primary-ink: #ffffff;
  --color-primary-soft: #f8dcdf;
  --color-accent: #e9112e;
  --color-accent-ink: #ffffff;
  --color-highlight: #f8d1d6;
  --color-focus: #e20421;
  --color-contrast-surface: #2b1518;
  --color-contrast-ink: #e7e4e5;
  --color-contrast-line: #544345;
  --color-contrast-accent: #f13c54;
  --overlay-scrim: linear-gradient(180deg, rgba(43, 21, 24, 0.35) 0%, rgba(43, 21, 24, 0.72) 55%, rgba(43, 21, 24, 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(49px, 10.1vw, 129px);
  --text-figure: clamp(41px, 7.3vw, 93px);
  --weight-heading: 890;
  --weight-body: 400;
  --leading-body: 1.7;
  --leading-heading: 1.25;
  --tracking-heading: -0.02em;
  --radius-sm: 0px;
  --radius-md: 0px;
  --radius-lg: 0px;
  --radius-pill: 0px;
  --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: 1140px;
  --measure: 66ch;
  --gutter: 24px;
  --section-y: 84px;
  --section-y-lg: 118px;
}

/* ============ reset ============ */
*, *::before, *::after { box-sizing: border-box; }
html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: 156px;
}
body {
  margin: 0;
  min-height: 100vh;
  background: 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);
  overflow-x: hidden;
}
h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
table { width: 100%; border-collapse: collapse; }
img, svg, video { display: block; max-width: 100%; }
hr { border: 0; border-top: var(--border-thin) solid var(--color-line); margin: 0; }
:focus-visible { outline: 2px solid var(--color-focus); outline-offset: 3px; }
::selection { background: var(--color-primary); color: var(--color-primary-ink); }
[id] { scroll-margin-top: 156px; }

/* ============ 中文排版 ============ */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  text-wrap: balance;
}
p, li, dd { text-wrap: pretty; }
.mono, .num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}
.measure { max-width: var(--measure); }
.display-title {
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: 0.92;
  letter-spacing: -0.035em;
  text-wrap: balance;
}
.figure-anchor {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: -0.045em;
  font-variant-numeric: tabular-nums;
  color: var(--color-ink);
}
.figure-anchor--accent { color: var(--color-accent); }
.figure-anchor--contrast { color: var(--color-contrast-ink); }
.label {
  display: inline-block;
  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);
}
.prose { max-width: var(--measure); font-size: var(--text-base); }
.prose p + p { margin-top: var(--space-3); }
.prose h2 { margin-top: var(--space-6); font-size: var(--text-2xl); }
.prose h3 { margin-top: var(--space-4); font-size: var(--text-xl); }
.prose ul { margin-top: var(--space-3); }
.prose ul li { position: relative; padding-left: var(--space-3); }
.prose ul li + li { margin-top: var(--space-1); }
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.85em;
  width: 12px;
  height: 1px;
  background: var(--color-primary);
}
.prose a { border-bottom: var(--border-thin) solid var(--color-line); }
.prose a:hover { color: var(--color-primary); border-bottom-color: var(--color-primary); }

/* ============ 布局 ============ */
.shell {
  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-3 { grid-column: span 3; }
.col-4 { grid-column: span 4; }
.col-6 { grid-column: span 6; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: span 12; }
.section { padding-block: var(--section-y); }
.section--lg { padding-block: var(--section-y-lg); }
.rule { width: 100%; }
.rule--tight { margin-block: var(--space-3); }
main { display: block; }
.skip-target:focus, #main-content:focus { outline: none; }

/* ============ skip link ============ */
.skip-link {
  position: absolute;
  left: var(--space-2);
  top: 0;
  z-index: 200;
  transform: translateY(-140%);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding: 10px var(--space-2);
  font-size: var(--text-sm);
  font-weight: 600;
  transition: transform 140ms ease-out;
}
.skip-link:focus { transform: translateY(0); }

/* ============ 头部 ============ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--color-surface);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  pointer-events: none;
}
.scroll-progress__bar {
  display: block;
  height: 100%;
  width: 100%;
  background: var(--color-primary);
  transform: scaleX(0);
  transform-origin: 0 50%;
}
.header-upper {
  background: var(--color-surface-alt);
  border-bottom: var(--border-thin) solid var(--color-line);
}
.header-upper__inner {
  display: grid;
  grid-template-columns: minmax(0, auto) minmax(0, 1fr) minmax(0, auto);
  align-items: end;
  column-gap: var(--space-4);
  padding-block: var(--space-3);
}
.brand {
  display: inline-flex;
  align-items: stretch;
  gap: var(--space-2);
}
.brand__mark {
  width: 6px;
  flex: none;
  background: var(--color-primary);
}
.brand__text {
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 4px;
}
.brand__name {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  letter-spacing: var(--tracking-heading);
  line-height: 1.1;
}
.brand__meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}
.header-brief {
  max-width: 56ch;
  font-size: var(--text-sm);
  line-height: 1.65;
  color: var(--color-ink-soft);
  padding-bottom: 2px;
}
.header-brief__tick {
  display: block;
  height: 9px;
  margin-top: var(--space-2);
  background-image: repeating-linear-gradient(90deg, var(--color-line) 0 1px, transparent 1px 11px);
  background-repeat: repeat-x;
  background-position: 0 100%;
  background-size: auto 9px;
}
.header-upper__aside {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 5px;
  text-align: right;
  padding-bottom: 2px;
}
.header-mail {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-ink);
  letter-spacing: -0.01em;
}
.header-lower { position: relative; background: var(--color-surface); }
.header-lower__inner {
  display: flex;
  align-items: stretch;
  justify-content: space-between;
  gap: var(--space-3);
  min-height: 60px;
}
.primary-nav { display: flex; align-items: stretch; }
.primary-nav__list { display: flex; align-items: stretch; }
.primary-nav__list li { display: flex; }
.primary-nav__list a {
  display: flex;
  align-items: center;
  padding: 0 14px;
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: -0.005em;
  color: var(--color-ink-soft);
  border-bottom: 2px solid transparent;
  transition: color 140ms ease-out, border-color 140ms ease-out, background-color 140ms ease-out;
}
.primary-nav__list a:hover,
.primary-nav__list a:focus-visible {
  color: var(--color-ink);
  border-bottom-color: var(--color-primary);
  background: var(--color-surface-alt);
}
.primary-nav__list a[aria-current="page"] {
  color: var(--color-ink);
  border-bottom-color: var(--color-primary);
}
.nav-toggle {
  display: none;
  align-items: center;
  gap: var(--space-1);
  min-height: 56px;
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--color-ink);
}
.nav-toggle__bars { position: relative; width: 20px; height: 12px; flex: none; }
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  background: currentColor;
}
.nav-toggle__bars::before { top: 0; }
.nav-toggle__bars::after { bottom: 0; }

/* ============ 按钮与行动入口 ============ */
.cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  padding: 0 var(--space-3);
  min-height: 44px;
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.02em;
  border: var(--border-thin) solid transparent;
  transition: background-color 140ms ease-out, color 140ms ease-out, border-color 140ms ease-out;
}
.cta--contrast {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-color: var(--color-contrast-surface);
}
.cta--contrast:hover,
.cta--contrast:focus-visible {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.cta--primary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  border-color: var(--color-primary);
}
.cta--primary:hover,
.cta--primary:focus-visible {
  background: color-mix(in srgb, var(--color-primary) 84%, var(--color-contrast-surface));
  border-color: transparent;
  color: var(--color-primary-ink);
}
.header-lower__inner .cta { align-self: stretch; min-height: 60px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  min-height: 44px;
  padding: 0 var(--space-3);
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.02em;
  background: transparent;
  color: var(--color-ink);
  border: var(--border-thin) solid var(--color-ink-muted);
  transition: background-color 140ms ease-out, color 140ms ease-out, border-color 140ms ease-out;
}
.btn:hover,
.btn:focus-visible {
  background: var(--color-contrast-surface);
  border-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.btn--primary {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-primary-ink);
}
.btn--primary:hover,
.btn--primary:focus-visible {
  background: color-mix(in srgb, var(--color-primary) 84%, var(--color-contrast-surface));
  border-color: transparent;
  color: var(--color-primary-ink);
}
.btn--ghost { border-color: var(--color-line); color: var(--color-ink-soft); }

/* ============ 标签与面包屑 ============ */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 8px;
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-ink-soft);
}
.tag--primary {
  background: var(--color-primary-soft);
  border-color: var(--color-primary-soft);
  color: color-mix(in srgb, var(--color-primary) 78%, var(--color-contrast-surface));
}
.tag--accent {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}
.tag--contrast {
  background: transparent;
  border-color: var(--color-contrast-line);
  color: var(--color-contrast-ink);
}
.breadcrumb { margin-bottom: var(--space-4); }
.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}
.breadcrumb__list li + li::before {
  content: "/";
  margin-right: var(--space-1);
  color: var(--color-line);
}
.breadcrumb__list a:hover { color: var(--color-primary); }
.breadcrumb__list [aria-current="page"] { color: var(--color-ink); }

/* ============ 章节抬头与条目 ============ */
.section-head {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--space-2) var(--gutter);
  align-items: baseline;
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
}
.section-head__index {
  grid-column: span 2;
  font-family: var(--font-mono);
  font-size: var(--text-4xl);
  font-weight: 700;
  line-height: 0.9;
  letter-spacing: -0.05em;
  color: var(--color-primary);
  font-variant-numeric: tabular-nums;
}
.section-head__title {
  grid-column: span 6;
  font-size: var(--text-3xl);
  line-height: 1.08;
}
.section-head__note {
  grid-column: span 4;
  font-size: var(--text-sm);
  line-height: 1.65;
  color: var(--color-ink-soft);
}
.entry {
  padding-block: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
}
.entry__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 4px var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}
.entry__title {
  margin-top: var(--space-1);
  font-size: var(--text-xl);
  line-height: 1.2;
  transition: color 140ms ease-out;
}
.entry__desc {
  margin-top: var(--space-1);
  max-width: var(--measure);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}
.entry:hover .entry__title { color: var(--color-primary); }

/* ============ 数据表与指标 ============ */
.table-scroll { overflow-x: auto; border-top: var(--border-thin) solid var(--color-ink-muted); }
.data-table { font-size: var(--text-sm); }
.data-table thead th {
  background: var(--color-surface-deep);
  padding: 10px 12px;
  text-align: left;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: 400;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-ink-soft);
  border-bottom: var(--border-thin) solid var(--color-line);
  white-space: nowrap;
}
.data-table td {
  padding: 12px;
  vertical-align: top;
  border-bottom: var(--border-thin) solid var(--color-line);
  line-height: 1.6;
}
.data-table tbody tr:hover td { background: var(--color-surface-alt); }
.data-table .num, .data-table th.num { text-align: right; }
.stat { display: flex; flex-direction: column; gap: 4px; }
.stat__value {
  font-family: var(--font-mono);
  font-size: var(--text-2xl);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
}
.stat__label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-ink-muted);
}

/* ============ 图片容器 ============ */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  width: 100%;
  aspect-ratio: 16 / 10;
  background: var(--color-surface-deep);
}
.media-frame--tall { aspect-ratio: 4 / 5; }
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(0.72) contrast(1.04);
}
.media-frame__body {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: var(--space-1);
  padding: var(--space-4);
  background: var(--overlay-scrim);
  color: var(--color-contrast-ink);
}
.media-frame__body .label { color: var(--color-contrast-ink); opacity: 0.78; }
.media-frame__body a:hover { color: var(--color-contrast-accent); }
.media-frame__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: var(--space-1) var(--space-2);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
}

/* ============ 强对比区块 ============ */
.block-contrast {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}
.block-contrast .label { color: var(--color-contrast-ink); opacity: 0.7; }
.block-contrast .rule,
.block-contrast hr { border-top-color: var(--color-contrast-line); }
.block-contrast .stat__label { color: var(--color-contrast-ink); opacity: 0.7; }
.block-contrast a:hover { color: var(--color-contrast-accent); }

/* ============ 筛选 ============ */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
}
.filter-btn {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 0 14px;
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-ink-soft);
  transition: background-color 140ms ease-out, color 140ms ease-out, border-color 140ms ease-out;
}
.filter-btn:hover { border-color: var(--color-ink-muted); color: var(--color-ink); }
.filter-btn[aria-pressed="true"] {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-ink);
}
[data-filter-item][hidden] { display: none; }
.filter-empty {
  margin-top: var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
}

/* ============ 显现与返回顶部 ============ */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 180ms ease-out, transform 180ms ease-out;
}
.js [data-reveal][data-revealed] { opacity: 1; transform: none; }
.to-top {
  position: fixed;
  right: var(--space-3);
  bottom: var(--space-3);
  z-index: 70;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border: var(--border-thin) solid var(--color-contrast-line);
  font-family: var(--font-mono);
  font-size: var(--text-base);
  opacity: 0;
  visibility: hidden;
  transition: opacity 140ms ease-out, visibility 140ms ease-out, background-color 140ms ease-out;
}
.to-top[data-visible] { opacity: 1; visibility: visible; }
.to-top:hover { background: var(--color-primary); border-color: var(--color-primary); color: var(--color-primary-ink); }

/* ============ 页脚 ============ */
.site-footer {
  background: var(--color-surface-alt);
  border-top: var(--border-thin) solid var(--color-line);
  padding-block: var(--space-8) var(--space-6);
}
.footer-frame {
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  padding: var(--space-6);
}
.footer-scale {
  height: 10px;
  margin-bottom: var(--space-6);
  background-image: repeating-linear-gradient(90deg, var(--color-line) 0 1px, transparent 1px 12px);
  background-repeat: repeat-x;
  background-size: auto 10px;
  border-bottom: var(--border-thin) solid var(--color-line);
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--space-4) var(--gutter);
}
.footer-col--brand { grid-column: span 4; }
.footer-col { grid-column: span 2; }
.footer-col--contact { grid-column: span 4; }
.footer-col .label { display: block; }
.brand--footer .brand__name { font-size: var(--text-lg); }
.footer-note {
  margin-top: var(--space-3);
  max-width: 40ch;
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}
.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  margin-top: var(--space-2);
}
.footer-links a {
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  transition: color 140ms ease-out;
}
.footer-links a:hover,
.footer-links a:focus-visible { color: var(--color-primary); }
.footer-links a[aria-current="page"] { color: var(--color-ink); font-weight: 600; }
.footer-contact {
  margin-top: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: -0.01em;
  color: var(--color-ink);
}
.footer-contact + .footer-contact { margin-top: 4px; }
.footer-address {
  margin-top: var(--space-2);
  max-width: 34ch;
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-ink-soft);
}
.footer-rule {
  margin-block: var(--space-6) var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
}
.footer-base {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--space-1) var(--space-4);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.06em;
  color: var(--color-ink-muted);
}

/* ============ 响应式 ============ */
@media (max-width: 1120px) {
  .primary-nav__list a { padding: 0 10px; }
}
@media (max-width: 960px) {
  html { scroll-padding-top: 128px; }
  [id] { scroll-margin-top: 128px; }
  .header-upper__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    column-gap: var(--space-2);
    padding-block: var(--space-2);
  }
  .header-brief { display: none; }
  .header-upper__aside { align-items: flex-end; }
  .brand__name { font-size: var(--text-lg); }
  .header-lower__inner { min-height: 56px; align-items: center; }
  .nav-toggle { display: inline-flex; }
  .primary-nav {
    position: absolute;
    left: calc(var(--gutter) * -1);
    right: calc(var(--gutter) * -1);
    top: 100%;
    z-index: 5;
    display: none;
    background: var(--color-surface);
    border-top: var(--border-thin) solid var(--color-line);
    border-bottom: var(--border-thin) solid var(--color-line);
  }
  .primary-nav[data-open] { display: block; }
  .primary-nav__list { flex-direction: column; align-items: stretch; }
  .primary-nav__list li { display: block; }
  .primary-nav__list a {
    height: auto;
    padding: 14px var(--gutter);
    border-bottom: var(--border-thin) solid var(--color-line);
    border-left: 3px solid transparent;
  }
  .primary-nav__list li:last-child a { border-bottom: 0; }
  .primary-nav__list a:hover,
  .primary-nav__list a:focus-visible {
    background: var(--color-surface-alt);
    border-bottom-color: var(--color-line);
    border-left-color: var(--color-line);
  }
  .primary-nav__list a[aria-current="page"] {
    border-bottom-color: var(--color-line);
    border-left-color: var(--color-primary);
  }
  .header-lower__inner .cta { align-self: center; min-height: 40px; padding: 0 var(--space-2); }
  .section-head__index { grid-column: span 2; font-size: var(--text-3xl); }
  .section-head__title { grid-column: span 10; font-size: var(--text-2xl); }
  .section-head__note { grid-column: span 10; grid-column-start: 3; }
  .col-3, .col-4 { grid-column: span 6; }
  .col-8 { grid-column: span 12; }
  .footer-frame { padding: var(--space-4); }
  .footer-col--brand { grid-column: span 12; }
  .footer-col { grid-column: span 6; }
  .footer-col--contact { grid-column: span 12; }
  .footer-scale { margin-bottom: var(--space-4); }
}
@media (max-width: 640px) {
  .col-3, .col-4, .col-6, .col-8 { grid-column: span 12; }
  .section-head__index { grid-column: span 3; font-size: var(--text-2xl); }
  .section-head__title { grid-column: span 9; font-size: var(--text-xl); }
  .section-head__note { grid-column: span 12; grid-column-start: auto; }
  .footer-col { grid-column: span 12; }
  .footer-base { flex-direction: column; }
  .to-top { right: var(--space-2); bottom: var(--space-2); }
  .media-frame__body { padding: var(--space-3); }
}

/* ============ 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;
  }
  .js [data-reveal] { opacity: 1; transform: none; }
  .scroll-progress__bar { transition: none; }
}