/* =========================================================
   轻量赛场 · 共享样式 /assets/site.css
   深空基底 + 面板中层 + 模块灰面 + 荧光青 + 暖橙
   ========================================================= */

/* ---------- 1. reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body { margin: 0; }

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

button, input, select, textarea {
  font: inherit;
  color: inherit;
  margin: 0;
}

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

h1, h2, h3, h4, h5, p, figure, blockquote { margin: 0; }

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

[hidden] { display: none !important; }

/* ---------- 2. 变量 ---------- */
:root {
  --ink: #0E1621;
  --panel: #16202B;
  --surface: #F2F5F8;
  --paper: #FFFFFF;
  --line: #C3CDD6;
  --muted: #5C6B79;
  --text: #101A24;
  --cyan: #00E5C8;
  --orange: #FF7A3D;
  --blue: #1E5BD6;
  --cyan-ink: #00806F;
  --orange-ink: #B23F0F;
  --on-dark: #E6EDF3;
  --on-dark-soft: #93A3B2;
  --hair: rgba(195, 205, 214, 0.22);

  --font-display: "PingFang SC", "Noto Sans SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-body: "PingFang SC", "Noto Sans SC", "Source Han Sans SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;

  --wrap: 1200px;
  --gutter: 20px;
  --header-h: 64px;
  --r: 6px;
  --dur: 180ms;
  --ease: cubic-bezier(0.2, 0.7, 0.3, 1);
}

/* ---------- 3. 中文排版 ---------- */
body {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
  letter-spacing: 0.01em;
  color: var(--text);
  background: var(--surface);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: 0.005em;
  color: var(--text);
}

h1 {
  font-weight: 900;
  font-size: clamp(28px, 4.4vw, 34px);
  line-height: 1.18;
}

h2 { font-size: 22px; line-height: 1.28; }
h3 { font-size: 17px; line-height: 1.4; }
h4 { font-size: 15px; line-height: 1.45; }

p { overflow-wrap: anywhere; }

a {
  color: var(--blue);
  text-decoration: none;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

a:hover { text-decoration: underline; }

strong { font-weight: 700; }

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

[id] { scroll-margin-top: calc(var(--header-h) + 24px); }

/* ---------- 4. 工具类 ---------- */
.wrap,
.container {
  width: min(var(--wrap), 100% - (var(--gutter) * 2));
  margin-inline: auto;
}

.mono {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
}

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

.hairline {
  height: 1px;
  background: var(--line);
  border: 0;
  margin: 0;
}

/* ---------- 5. 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: 14px;
  top: 10px;
  z-index: 120;
  display: inline-block;
  padding: 10px 16px;
  background: var(--cyan);
  color: #04201C;
  font-size: 14px;
  font-weight: 700;
  border-radius: var(--r);
  text-decoration: none;
  transform: translateY(-220%);
  transition: transform 160ms var(--ease);
}

.skip-link:focus,
.skip-link:focus-visible {
  transform: translateY(0);
  text-decoration: none;
  outline: 2px solid #FFFFFF;
  outline-offset: 2px;
}

/* ---------- 6. 头部 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--ink);
  color: var(--on-dark);
  border-bottom: 1px solid var(--hair);
}

.header-bar {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: clamp(12px, 2vw, 32px);
  min-height: var(--header-h);
  padding-block: 10px;
}

.site-header[data-shrink] .header-bar {
  min-height: 54px;
  padding-block: 6px;
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  color: var(--on-dark);
  text-decoration: none;
  flex: none;
}

.brand:hover { text-decoration: none; color: #FFFFFF; }

.brand__index {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  border: 1px solid rgba(0, 229, 200, 0.45);
  border-radius: 3px;
  padding: 1px 6px;
}

.brand__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 17px;
  letter-spacing: 0.05em;
}

/* 移动按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  background: transparent;
  border: 1px solid var(--hair);
  border-radius: 999px;
  color: var(--on-dark);
  cursor: pointer;
}

.nav-toggle__bars,
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  display: block;
  width: 14px;
  height: 1px;
  background: var(--cyan);
  content: "";
  position: relative;
}

.nav-toggle__bars::before { position: absolute; top: -4px; }
.nav-toggle__bars::after { position: absolute; top: 4px; }

.nav-toggle__text {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--on-dark-soft);
}

.nav-toggle[aria-expanded="true"] {
  border-color: rgba(0, 229, 200, 0.55);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__text { color: var(--cyan); }

/* 主导航 */
.site-nav { justify-self: center; min-width: 0; }

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.site-nav__link {
  display: inline-flex;
  align-items: baseline;
  gap: 6px;
  padding: 6px 10px 5px;
  border-bottom: 2px solid transparent;
  border-radius: 3px 3px 0 0;
  color: #B7C4D1;
  font-size: 14px;
  white-space: nowrap;
  text-decoration: none;
}

.site-nav__link:hover {
  color: #FFFFFF;
  background: rgba(255, 255, 255, 0.06);
  text-decoration: none;
}

.site-nav__num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: #6B7B8C;
}

.site-nav__link[aria-current="page"] {
  color: #FFFFFF;
  border-bottom-color: var(--cyan);
}

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

/* 状态灯 */
.header-status {
  justify-self: end;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: #8C9BAA;
  white-space: nowrap;
}

.status-lamp {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(0, 229, 200, 0.16);
  flex: none;
}

/* 滚动进度 */
.header-progress {
  height: 2px;
  background: rgba(195, 205, 214, 0.14);
}

.header-progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: var(--cyan);
  transition: width 120ms linear;
}

/* 右下固定入口 */
.floating-cta {
  position: fixed;
  right: clamp(14px, 3vw, 34px);
  bottom: clamp(14px, 3vw, 34px);
  z-index: 90;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 18px;
  background: var(--orange);
  color: #1A0D05;
  border: 1px solid #FF9A66;
  border-radius: var(--r);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  box-shadow: 0 4px 0 rgba(0, 0, 0, 0.22);
  text-decoration: none;
}

.floating-cta:hover {
  background: #FF8F55;
  text-decoration: none;
}

.floating-cta__arrow {
  font-family: var(--font-mono);
  font-size: 13px;
  opacity: 0.8;
}

/* ---------- 7. 页脚 ---------- */
.site-footer {
  background: var(--ink);
  color: #C7D2DC;
  border-top: 1px solid rgba(0, 229, 200, 0.25);
  margin-top: 0;
}

.footer-scale {
  height: 10px;
  background-image: repeating-linear-gradient(90deg, rgba(195, 205, 214, 0.5) 0 1px, transparent 1px 26px);
  background-repeat: repeat-x;
  background-size: auto 6px;
  background-position: 0 0;
  opacity: 0.55;
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(220px, 1.35fr) minmax(170px, 1fr) minmax(240px, 1.25fr);
  gap: clamp(20px, 4vw, 56px);
  padding: clamp(30px, 5vw, 54px) 0 22px;
}

.footer-kicker {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.footer-brand {
  margin-top: 10px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 22px;
  letter-spacing: 0.05em;
  color: #FFFFFF;
}

.footer-claim {
  margin-top: 8px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--on-dark-soft);
  max-width: 26ch;
}

.footer-title {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: #7E8D9C;
  margin-bottom: 12px;
}

.footer-list li + li { margin-top: 8px; }

.footer-list--legal {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid rgba(195, 205, 214, 0.16);
}

.footer-list a {
  display: inline-block;
  font-size: 14px;
  color: #C7D2DC;
  border-bottom: 1px solid transparent;
  padding-bottom: 1px;
}

.footer-list a:hover {
  color: #FFFFFF;
  border-bottom-color: var(--cyan);
  text-decoration: none;
}

.footer-list a[aria-current="page"] {
  color: var(--cyan);
  border-bottom-color: rgba(0, 229, 200, 0.5);
}

.footer-contact li + li { margin-top: 9px; }

.footer-contact__row {
  display: flex;
  align-items: baseline;
  gap: 10px;
}

.footer-key {
  flex: none;
  min-width: 44px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: #7E8D9C;
}

.footer-value {
  font-size: 14px;
  line-height: 1.65;
  color: #C7D2DC;
  overflow-wrap: anywhere;
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  padding: 14px 0 30px;
  border-top: 1px solid rgba(195, 205, 214, 0.16);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: #7E8D9C;
}

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 18px;
  border: 1px solid transparent;
  border-radius: var(--r);
  font-size: 15px;
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
  text-decoration: none;
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.btn:hover { text-decoration: none; }

.btn--primary {
  background: var(--orange);
  border-color: #FF9A66;
  color: #1A0D05;
}

.btn--primary:hover { background: #FF8F55; }

.btn--ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--text);
}

.btn--ghost:hover { border-color: var(--text); }

.btn--onDark {
  background: transparent;
  border-color: rgba(195, 205, 214, 0.35);
  color: var(--on-dark);
}

.btn--onDark:hover {
  border-color: var(--cyan);
  color: #FFFFFF;
}

/* ---------- 9. 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.breadcrumbs__item {
  color: var(--muted);
  text-decoration: none;
}

a.breadcrumbs__item { color: var(--blue); }

.breadcrumbs__sep {
  color: var(--line);
  font-size: 11px;
}

.breadcrumbs [aria-current="page"] {
  color: var(--text);
  text-decoration: none;
}

/* ---------- 10. 分区与内容容器 ---------- */
.section { padding-block: clamp(30px, 5vw, 64px); }

.section--surface { background: var(--surface); }
.section--paper { background: var(--paper); }

.section--dark {
  background: var(--ink);
  color: var(--on-dark);
}

.section--dark h1,
.section--dark h2,
.section--dark h3 { color: #FFFFFF; }

.section--dark .section__title { color: #FFFFFF; }

.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 20px;
  padding-bottom: 12px;
  margin-bottom: clamp(16px, 3vw, 28px);
  border-bottom: 1px solid var(--line);
}

.section--dark .section__head { border-bottom-color: var(--hair); }

.section__kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--cyan-ink);
}

.section--dark .section__kicker { color: var(--cyan); }

.section__title { font-size: 22px; }

.section__note {
  margin-left: auto;
  font-size: 13px;
  color: var(--muted);
}

.section--dark .section__note { color: var(--on-dark-soft); }

.lede {
  font-size: 17px;
  line-height: 1.75;
  color: var(--muted);
  max-width: 62ch;
}

.section--dark .lede { color: #B7C4D1; }

.prose p + p { margin-top: 14px; }

.prose p {
  font-size: 16px;
  line-height: 1.75;
  color: var(--muted);
}

.prose h3 { margin-top: 22px; margin-bottom: 8px; }

/* ---------- 11. 网格 ---------- */
.grid {
  display: grid;
  gap: clamp(12px, 1.6vw, 18px);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--auto { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

/* ---------- 12. Bento 模块板 ---------- */
.bento {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(12px, 1.6vw, 18px);
}

.bento__cell {
  position: relative;
  grid-column: span 12;
  padding: clamp(16px, 2vw, 24px);
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 3px solid var(--line);
  border-radius: var(--r);
  transition: border-left-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.bento__cell:hover { border-left-color: var(--cyan); }

.bento__cell--dark {
  background: var(--panel);
  border-color: var(--hair);
  border-left-color: rgba(195, 205, 214, 0.3);
  color: var(--on-dark);
}

.bento__cell--dark:hover { border-left-color: var(--orange); }

.bento__index {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.bento__cell--dark .bento__index { color: var(--cyan); }

.bento__title {
  margin-top: 8px;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 800;
  line-height: 1.4;
  color: var(--text);
}

.bento__cell--dark .bento__title { color: #FFFFFF; }

.bento__body {
  margin-top: 8px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.bento__cell--dark .bento__body { color: #B7C4D1; }

.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-9 { grid-column: span 9; }
.span-12 { grid-column: span 12; }

/* ---------- 13. 卡片与面板 ---------- */
.card {
  position: relative;
  padding: clamp(16px, 2vw, 22px);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--r);
}

.card--dark {
  background: var(--panel);
  border-color: var(--hair);
  color: var(--on-dark);
}

.card__label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.card--dark .card__label { color: var(--cyan); }

.panel {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--r);
  overflow: hidden;
}

.panel__head {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}

.panel__title {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.panel__body { padding: clamp(14px, 2vw, 20px); }

/* ---------- 14. 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r);
}

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

.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--1x1 { aspect-ratio: 1 / 1; }
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }

.media-frame__tag {
  position: absolute;
  top: 0;
  left: 0;
  padding: 4px 9px;
  background: var(--paper);
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  border-bottom-right-radius: var(--r);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.media-frame__cap {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 5px 10px;
  background: rgba(14, 22, 33, 0.88);
  border-top: 1px solid rgba(0, 229, 200, 0.4);
  border-top-right-radius: var(--r);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: #C7D2DC;
}

/* ---------- 15. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 8px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
  white-space: nowrap;
}

.tag--cyan {
  border-color: rgba(0, 128, 111, 0.4);
  background: rgba(0, 229, 200, 0.1);
  color: var(--cyan-ink);
}

.tag--orange {
  border-color: rgba(178, 63, 15, 0.4);
  background: rgba(255, 122, 61, 0.12);
  color: var(--orange-ink);
}

.tag--onDark {
  background: rgba(255, 255, 255, 0.04);
  border-color: rgba(195, 205, 214, 0.3);
  color: #B7C4D1;
}

/* ---------- 16. 筛选条 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 10px 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.filter-bar__label {
  margin-right: 4px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.filter-btn {
  padding: 6px 12px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 3px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
  cursor: pointer;
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

.filter-btn:hover {
  border-color: var(--text);
  color: var(--text);
}

.filter-btn[aria-pressed="true"] {
  background: var(--orange);
  border-color: var(--orange);
  color: #1A0D05;
}

.section--dark .filter-bar { border-color: var(--hair); }

.section--dark .filter-btn {
  background: transparent;
  border-color: var(--hair);
  color: #B7C4D1;
}

.section--dark .filter-btn[aria-pressed="true"] {
  background: var(--orange);
  border-color: var(--orange);
  color: #1A0D05;
}

/* ---------- 17. 折叠面板 ---------- */
.fold {
  border-top: 1px solid var(--line);
}

.fold:last-child { border-bottom: 1px solid var(--line); }

.fold__btn {
  display: flex;
  width: 100%;
  align-items: baseline;
  gap: 12px;
  padding: 14px 2px;
  background: none;
  border: 0;
  text-align: left;
  cursor: pointer;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
}

.fold__btn::before {
  content: "";
  flex: none;
  width: 2px;
  height: 14px;
  background: var(--line);
  transition: height var(--dur) var(--ease), background-color var(--dur) var(--ease);
}

.fold__btn[aria-expanded="true"]::before {
  height: 24px;
  background: var(--orange);
}

.fold__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  font-weight: 400;
  color: var(--muted);
}

.fold__panel {
  max-height: 0;
  overflow: hidden;
  transition: max-height 200ms var(--ease);
}

.fold__inner {
  padding: 2px 2px 18px 16px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--muted);
}

.section--dark .fold { border-color: var(--hair); }

.section--dark .fold__btn { color: var(--on-dark); }

.section--dark .fold__inner { color: #B7C4D1; }

/* ---------- 18. 显现动效 ---------- */
html[data-js] [data-reveal] {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 200ms var(--ease), transform 200ms var(--ease);
}

html[data-js] [data-reveal][data-revealed] {
  opacity: 1;
  transform: none;
}

/* ---------- 19. 响应式 ---------- */
@media (max-width: 1020px) {
  .header-bar {
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-areas:
      "brand toggle"
      "nav nav";
    align-items: center;
    gap: 0;
  }

  .brand { grid-area: brand; }
  .nav-toggle { grid-area: toggle; display: inline-flex; }
  .header-status { display: none; }

  .site-nav {
    grid-area: nav;
    display: none;
    justify-self: stretch;
    min-width: 0;
    margin-top: 8px;
    border-top: 1px solid var(--hair);
  }

  .site-nav[data-open] { display: block; }

  .site-nav__list {
    flex-direction: row;
    gap: 6px;
    padding: 10px 0 12px;
    overflow-x: auto;
    scrollbar-width: thin;
    -webkit-overflow-scrolling: touch;
  }

  .site-nav__link {
    flex: none;
    padding: 6px 12px;
    border: 1px solid var(--hair);
    border-radius: 999px;
    font-size: 13px;
  }

  .site-nav__link[aria-current="page"] {
    border-color: var(--cyan);
    background: rgba(0, 229, 200, 0.08);
  }

  .span-3,
  .span-4,
  .span-5,
  .span-6,
  .span-7,
  .span-8,
  .span-9 { grid-column: span 12; }

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

@media (max-width: 720px) {
  :root { --gutter: 16px; }

  .grid--2,
  .grid--3 { grid-template-columns: minmax(0, 1fr); }

  .footer-grid {
    grid-template-columns: minmax(0, 1fr);
    gap: 26px;
  }

  .footer-meta { gap: 6px 16px; }

  .floating-cta {
    right: 14px;
    bottom: 14px;
    padding: 11px 15px;
    font-size: 14px;
  }

  .section__note { margin-left: 0; }
}

@media (max-width: 420px) {
  .brand__name { font-size: 16px; }
  .brand__index { font-size: 10px; }
}

/* ---------- 20. 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;
  }

  html[data-js] [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }

  .header-progress__bar { transition: none; }
}