/* ============================================================
   华体会体育 · site.css
   计分板框架：深墨蓝底 / 竞速橙红信号 / 电光青刻度 / 荧光黄绿版本
   ============================================================ */

/* ---------- 1. 变量 ---------- */
:root {
  --ink: #0A1020;
  --panel: #131C2E;
  --line: #26334C;
  --signal: #FF4B1F;
  --signal-press: #C43A12;
  --signal-soft: #FF4B1F29;
  --cyan: #35E3D2;
  --lime: #CBF25A;
  --fog: #F3F6FA;
  --muted: #97A5BC;
  --mist: #E6EBF2;
  --dim: #6C7B95;

  --fs-12: 0.75rem;
  --fs-16: 1rem;
  --fs-20: 1.25rem;
  --fs-28: 1.75rem;
  --fs-40: 2.5rem;
  --fs-56: 3.5rem;
  --fs-88: 5.5rem;

  --r-sm: 3px;
  --r: 10px;
  --r-lg: 18px;

  --wrap: 1240px;
  --shear: 6deg;
  --header-min: 76px;

  --ease: cubic-bezier(.22, .61, .36, 1);
  --sans: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Noto Sans SC", "Source Han Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: ui-monospace, "SFMono-Regular", "JetBrains Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

/* ---------- 2. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-padding-top: 140px;
}

body,
h1, h2, h3, h4, h5, h6,
p, ul, ol, li, figure, figcaption,
blockquote, dl, dd, fieldset, legend {
  margin: 0;
  padding: 0;
}

ul, ol { list-style: none; }

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

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

a { color: inherit; }

html[data-version="legacy"] .ver-new { display: none !important; }
html:not([data-version="legacy"]) .ver-legacy { display: none !important; }

/* ---------- 3. 基础排版 ---------- */
body {
  background: var(--ink);
  color: var(--fog);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: 0.005em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

h1 { font-size: clamp(var(--fs-40), 7vw, var(--fs-88)); }
h2 { font-size: clamp(var(--fs-28), 4vw, var(--fs-56)); }
h3 { font-size: clamp(var(--fs-20), 2.4vw, var(--fs-28)); line-height: 1.25; }
h4 { font-size: var(--fs-20); line-height: 1.35; }

p { max-width: 36em; }

strong { font-weight: 800; }

code, kbd, samp { font-family: var(--mono); font-size: 0.94em; }

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

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 2px;
}

/* ---------- 4. 布局容器 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: clamp(14px, 3vw, 32px);
}

.section {
  padding-block: clamp(40px, 6vw, 88px);
  position: relative;
}

.section--mist {
  background: var(--mist);
  color: var(--ink);
  --muted: #4E5D78;
  --dim: #5B6A85;
  --line: #C8D3E3;
  --panel: #FFFFFF;
  --fog: #0A1020;
}

.section--mist ::selection { background: var(--ink); color: var(--lime); }

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2.4vw, 28px);
}

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

/* ---------- 5. 标题组与正文 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: var(--fs-12);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 14px;
}

.eyebrow::before {
  content: "";
  width: 14px;
  height: 2px;
  background: var(--signal);
}

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 16px 32px;
  margin-bottom: clamp(20px, 3vw, 36px);
}

.section-title { max-width: 22em; }

.section-title em {
  font-style: normal;
  color: var(--signal);
}

.section-sub {
  font-size: var(--fs-16);
  line-height: 1.75;
  color: var(--muted);
  max-width: 34em;
}

.lede {
  font-size: clamp(var(--fs-16), 1.4vw, 1.125rem);
  line-height: 1.78;
  color: var(--muted);
  max-width: 34em;
}

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 20px;
  border: 1px solid transparent;
  border-radius: var(--r-sm);
  font-family: var(--sans);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.01em;
  text-decoration: none;
  cursor: pointer;
  transition: background .18s var(--ease), color .18s var(--ease), border-color .18s var(--ease), transform .18s var(--ease);
}

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

.btn-primary:hover { background: #FF6A42; transform: translateY(-1px); }
.btn-primary:active { background: var(--signal-press); color: var(--fog); transform: none; }

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

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

.btn-sm { min-height: 38px; padding: 0 14px; font-size: 14px; }

/* ---------- 7. 跳过链接 ---------- */
.skip-link {
  position: absolute;
  left: 12px;
  top: -120px;
  z-index: 200;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 18px;
  background: var(--lime);
  color: var(--ink);
  font-weight: 800;
  font-size: 14px;
  text-decoration: none;
  border-radius: var(--r-sm);
  transition: top .16s var(--ease);
}

.skip-link:focus { top: 12px; }

/* ---------- 8. 页头 · 计分板框架 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: var(--ink);
  border-bottom: 1px solid var(--line);
  transition: box-shadow .2s var(--ease);
}

.site-header::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background: var(--signal);
}

.site-header[data-scrolled] { box-shadow: 0 10px 30px rgba(0, 0, 0, .55); }

.header-bar {
  position: relative;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto auto;
  align-items: stretch;
  gap: clamp(10px, 2vw, 26px);
  min-height: var(--header-min);
  transition: min-height .2s var(--ease);
}

.site-header[data-scrolled] .header-bar { min-height: 60px; }

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  align-self: center;
  padding-block: 10px;
  color: var(--fog);
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.02em;
  text-decoration: none;
  white-space: nowrap;
}

.brand:hover .brand-text em { color: var(--fog); }

.brand-ping {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--signal);
  box-shadow: 0 0 0 0 rgba(255, 75, 31, .55);
  animation: brand-ping 2.4s var(--ease) infinite;
  flex: none;
}

@keyframes brand-ping {
  0%   { box-shadow: 0 0 0 0 rgba(255, 75, 31, .55); }
  70%  { box-shadow: 0 0 0 9px rgba(255, 75, 31, 0); }
  100% { box-shadow: 0 0 0 0 rgba(255, 75, 31, 0); }
}

.brand-text { display: inline-flex; align-items: baseline; gap: 6px; }

.brand-text em {
  font-style: normal;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--signal);
  transition: color .18s var(--ease);
}

/* 导航嵌在边框里 */
.site-nav { display: flex; align-items: stretch; min-width: 0; }

.nav-list { display: flex; align-items: stretch; height: 100%; }

.nav-link {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 14px;
  color: var(--muted);
  font-size: 15px;
  font-weight: 700;
  text-decoration: none;
  white-space: nowrap;
  transition: color .16s var(--ease), background .16s var(--ease);
}

.nav-link:hover { color: var(--fog); background: var(--signal-soft); }

.nav-link[aria-current="page"] {
  background: var(--signal);
  color: var(--ink);
  box-shadow: inset 0 -1px 0 var(--signal);
}

.nav-link[aria-current="page"]:hover { background: var(--signal); color: var(--ink); }

/* 右侧数据条 */
.header-data {
  display: flex;
  align-items: center;
  gap: 18px;
  align-self: center;
  padding-left: 18px;
  border-left: 1px solid var(--line);
  font-family: var(--mono);
}

.data-item { display: flex; flex-direction: column; gap: 1px; }

.data-label {
  font-size: 10px;
  letter-spacing: 0.12em;
  color: var(--dim);
  line-height: 1.4;
}

.data-value {
  font-size: 14px;
  line-height: 1.3;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.04em;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  align-self: center;
}

/* 移动端汉堡 */
.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  padding: 0;
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  cursor: pointer;
  transition: border-color .16s var(--ease);
}

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

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: var(--fog);
  transition: background .18s var(--ease);
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: var(--fog);
  transition: transform .2s var(--ease);
}

.nav-toggle-bars::before { top: -6px; }
.nav-toggle-bars::after { top: 6px; }

.site-header[data-open] .nav-toggle-bars { background: transparent; }
.site-header[data-open] .nav-toggle-bars::before { transform: translateY(6px) rotate(45deg); }
.site-header[data-open] .nav-toggle-bars::after { transform: translateY(-6px) rotate(-45deg); }

/* 抽屉内版本切换 */
.nav-extra {
  display: none;
  align-items: center;
  gap: 12px;
  padding: 18px 12px 4px;
  border-top: 1px solid var(--line);
  margin-top: 10px;
}

.nav-extra-label {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--dim);
}

/* 滚动数据带 */
.data-strip {
  overflow: hidden;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  max-height: 40px;
  transition: max-height .22s var(--ease), opacity .22s var(--ease);
}

.site-header[data-scrolled] .data-strip {
  max-height: 0;
  opacity: 0;
  border-bottom-color: transparent;
}

.strip-track {
  display: flex;
  width: max-content;
  animation: strip-scroll 44s linear infinite;
}

.data-strip:hover .strip-track { animation-play-state: paused; }

.strip-group {
  display: flex;
  align-items: center;
  gap: 30px;
  padding: 6px 30px 6px 14px;
}

.strip-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
  white-space: nowrap;
}

.strip-item::before {
  content: "";
  width: 5px;
  height: 5px;
  background: var(--cyan);
  flex: none;
}

@keyframes strip-scroll {
  from { transform: translate3d(0, 0, 0); }
  to   { transform: translate3d(-50%, 0, 0); }
}

/* ---------- 9. 页脚 · 四栏索引 ---------- */
.site-footer {
  position: relative;
  background: var(--ink);
  border-top: 1px solid var(--line);
}

.footer-rule {
  height: 2px;
  background: linear-gradient(90deg, var(--signal) 0 74%, var(--cyan) 74% 100%);
}

.footer-inner { padding-block: clamp(30px, 4.5vw, 60px) 24px; }

.footer-top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 28px;
  padding-bottom: 22px;
  margin-bottom: clamp(22px, 3vw, 36px);
  border-bottom: 1px solid var(--line);
}

.footer-brand {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
  font-size: 22px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--fog);
  max-width: none;
}

.footer-brand-en {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--signal);
}

.footer-tagline {
  font-size: 14px;
  color: var(--muted);
  max-width: none;
}

.footer-stamp {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
  max-width: none;
}

.dot-live {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 8px rgba(53, 227, 210, .8);
  flex: none;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr 1.45fr 1.2fr;
  gap: clamp(20px, 3vw, 40px);
}

.footer-col { min-width: 0; }

.footer-title {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--cyan);
  margin-bottom: 12px;
}

.footer-list { display: grid; gap: 0; }

.footer-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--fog);
  font-size: 15px;
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}

.footer-link:hover { color: var(--signal); border-bottom-color: var(--signal); }

.footer-list--plain { gap: 10px; }

.footer-contact {
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
  max-width: 26em;
  word-break: break-word;
}

.footer-muted { color: var(--dim); font-size: 13px; }

.footer-note {
  margin-top: 12px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--dim);
}

.footer-list--legal { margin-top: 14px; }

/* 版本切换器 */
.version-switch {
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  overflow: hidden;
  background: var(--panel);
}

.version-btn {
  min-height: 44px;
  padding: 0 16px;
  background: transparent;
  border: 0;
  border-right: 1px solid var(--line);
  color: var(--muted);
  font-family: var(--sans);
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: background .16s var(--ease), color .16s var(--ease);
}

.version-btn:last-child { border-right: 0; }
.version-btn:hover { color: var(--fog); background: var(--signal-soft); }

.version-btn[aria-pressed="true"] {
  background: var(--lime);
  color: var(--ink);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px 24px;
  margin-top: clamp(24px, 3vw, 40px);
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.footer-legal {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.05em;
  color: var(--dim);
  max-width: none;
}

.footer-legal--meta { color: var(--muted); }

/* ---------- 10. 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  min-height: 24px;
  display: inline-flex;
  align-items: center;
}

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

.crumb-sep { color: #46567A; }

/* ---------- 11. 面板 ---------- */
.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r);
  padding: clamp(18px, 2.4vw, 28px);
}

.panel-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px 18px;
  padding-bottom: 14px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.panel-head h3 { font-size: var(--fs-20); }

/* ---------- 12. 索引表 ---------- */
.index-list {
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.index-row {
  position: relative;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto auto;
  align-items: center;
  gap: clamp(10px, 2vw, 22px);
  min-height: 56px;
  padding: 12px 14px 12px 0;
  border-bottom: 1px solid var(--line);
  color: inherit;
  text-decoration: none;
  transition: background .18s var(--ease), transform .18s var(--ease);
}

.index-row::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 0;
  background: var(--signal);
  transition: height .18s var(--ease);
}

.index-row:hover { background: var(--signal-soft); transform: translateX(2px); }
.index-row:hover::before { height: 100%; }

.index-num {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.index-title {
  font-size: 17px;
  font-weight: 700;
  line-height: 1.45;
}

.index-meta {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.05em;
  color: var(--muted);
  white-space: nowrap;
}

.index-arrow {
  font-family: var(--mono);
  font-size: 15px;
  color: var(--signal);
  opacity: 0;
  transform: translateX(-4px);
  transition: opacity .18s var(--ease), transform .18s var(--ease);
}

.index-row:hover .index-arrow,
.index-row:focus-visible .index-arrow { opacity: 1; transform: translateX(0); }

/* ---------- 13. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 8px;
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.6;
  letter-spacing: 0.08em;
  border: 1px solid var(--line);
  color: var(--muted);
  background: transparent;
  white-space: nowrap;
}

.tag--new { border-radius: 0; border-color: var(--signal); color: var(--signal); }

.tag--legacy {
  border-color: var(--lime);
  background: var(--lime);
  color: var(--ink);
  clip-path: polygon(9px 0, 100% 0, 100% 100%, 0 100%, 0 9px);
}

.tag--live { border-color: var(--cyan); color: var(--cyan); }

/* ---------- 14. 图片容器基础规则 ---------- */
.frame-img {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--r);
  isolation: isolate;
}

.frame-img > img,
.frame-img > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform .5s var(--ease);
}

.frame-img:hover > img,
.frame-img:hover > picture > img { transform: scale(1.03); }

.frame-img::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(158deg, rgba(255, 75, 31, .18), rgba(255, 75, 31, 0) 52%),
              linear-gradient(0deg, rgba(10, 16, 32, .55), rgba(10, 16, 32, 0) 46%);
}

.frame-img--wide { aspect-ratio: 16 / 9; }
.frame-img--tall { aspect-ratio: 4 / 5; }
.frame-img--square { aspect-ratio: 1 / 1; }

.frame-img--shear {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), 0 100%);
}

.frame-img--shear::after { background: linear-gradient(158deg, rgba(255, 75, 31, .2), rgba(255, 75, 31, 0) 55%); }

.frame-cap {
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
  line-height: 1.6;
  max-width: 44em;
}

/* ---------- 15. 分段切换 ---------- */
.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  border-bottom: 1px solid var(--line);
}

.tab {
  min-height: 44px;
  padding: 0 16px;
  background: transparent;
  border: 1px solid transparent;
  border-bottom: 0;
  border-radius: var(--r-sm) var(--r-sm) 0 0;
  color: var(--muted);
  font-family: var(--sans);
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  transition: background .16s var(--ease), color .16s var(--ease);
}

.tab:hover { color: var(--fog); background: var(--signal-soft); }

.tab[aria-selected="true"] {
  background: var(--panel);
  color: var(--fog);
  border-color: var(--line);
  box-shadow: inset 0 2px 0 var(--signal);
}

.tabpanel { padding-top: clamp(16px, 2.4vw, 26px); }
.tabpanel[hidden] { display: none; }

/* ---------- 16. 锚点目录 ---------- */
.anchor-rail {
  position: sticky;
  top: 132px;
  display: grid;
  gap: 2px;
  align-content: start;
  padding-left: 12px;
  border-left: 1px solid var(--line);
}

.anchor-link {
  display: block;
  min-height: 34px;
  padding: 6px 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
  text-decoration: none;
  transition: color .16s var(--ease);
}

.anchor-link:hover { color: var(--fog); }

.anchor-link.is-active {
  color: var(--signal);
  font-weight: 700;
  box-shadow: -13px 0 0 -11px var(--signal);
}

/* ---------- 17. 旁注 ---------- */
.note {
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
  border-left: 2px solid var(--line);
  padding-left: 12px;
  max-width: 32em;
}

.note strong { color: var(--fog); }

/* ---------- 18. 滚动进度 ---------- */
.scroll-progress {
  position: fixed;
  left: 0;
  top: 0;
  width: 100%;
  height: 3px;
  z-index: 95;
  pointer-events: none;
  background: transparent;
}

.scroll-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--signal), var(--cyan));
}

/* ---------- 19. 显现 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity .5s var(--ease), transform .5s var(--ease);
}

[data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ---------- 20. 响应式 ---------- */
@media (max-width: 1120px) {
  .header-data { display: none; }
}

@media (max-width: 1023px) {
  :root { --header-min: 66px; }

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

  .site-nav {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    z-index: 6;
    flex-direction: column;
    padding: 10px clamp(14px, 3vw, 28px) 20px;
    background: var(--panel);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    clip-path: polygon(0 16px, 100% 0, 100% 100%, 0 100%);
    box-shadow: 0 26px 50px rgba(0, 0, 0, .55);
    max-height: calc(100vh - 70px);
    overflow-y: auto;
  }

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

  .nav-list {
    flex-direction: column;
    height: auto;
    width: 100%;
  }

  .nav-link {
    min-height: 48px;
    padding: 0 12px;
    border-bottom: 1px solid var(--line);
    font-size: 16px;
  }

  .nav-link[aria-current="page"] { box-shadow: none; }

  .nav-extra { display: flex; }

  .nav-toggle { display: inline-flex; }

  .data-strip { max-height: 34px; }
  .site-header[data-scrolled] .data-strip { max-height: 34px; opacity: 1; border-bottom-color: var(--line); }

  .strip-group { gap: 20px; padding-inline: 14px 20px; }

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

  .anchor-rail { position: static; top: auto; border-left: 0; padding-left: 0; border-top: 1px solid var(--line); padding-top: 10px; }
  .anchor-link.is-active { box-shadow: none; }

  .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 720px) {
  body { font-size: 16px; }

  .header-bar { gap: 10px; }

  .brand { font-size: 18px; }

  .header-actions .btn-sm { min-height: 40px; padding: 0 12px; font-size: 13px; }

  .footer-top { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 620px) {
  .grid { grid-template-columns: 1fr; }
  .col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-9, .col-12 { grid-column: 1 / -1; }

  .index-row {
    grid-template-columns: auto minmax(0, 1fr) auto;
    row-gap: 4px;
    align-items: start;
  }

  .index-meta { grid-column: 2 / 3; }

  .footer-grid { grid-template-columns: 1fr; }

  .footer-bottom { flex-direction: column; }
}

/* ---------- 21. 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }

  .strip-track { animation: none; }
  .data-strip { overflow-x: auto; }
  .brand-ping { animation: none; box-shadow: 0 0 0 3px rgba(255, 75, 31, .28); }

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

  .index-row:hover { transform: none; }
  .site-header[data-scrolled] .data-strip { max-height: 40px; opacity: 1; }
}