/* =====================================================================
   /assets/site.css — B体育官网 共享外壳（reset / 变量 / 头尾 / 通用组件）
   设计依据：夜场战术板 · 目录型内容地图 · 切角面板与斜向引导线
   ===================================================================== */

/* ---------- reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, h4, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video { max-width: 100%; display: block; }
button { font: inherit; color: inherit; }
table { border-collapse: collapse; }
html, body { min-height: 100%; }

/* ---------- 变量 ---------- */
:root {
  --ink: #071A12;
  --ink-2: #101312;
  --panel: #142B22;
  --panel-deep: #0B1E16;
  --lime: #C7FF2E;
  --orange: #FF8A3D;
  --snow: #F2FFF7;
  --mist: #8CA79B;
  --electro: #5CE1E6;
  --violet: #B69CFF;

  --line: rgba(140, 167, 155, .22);
  --line-soft: rgba(140, 167, 155, .12);
  --line-strong: rgba(199, 255, 46, .45);
  --lime-wash: rgba(199, 255, 46, .08);
  --orange-wash: rgba(255, 138, 61, .08);

  --font-display: 'Oswald', 'Barlow Condensed', 'Noto Sans SC', sans-serif;
  --font-body: 'Inter', 'Noto Sans SC', 'PingFang SC', sans-serif;
  --font-mono: 'JetBrains Mono', 'Roboto Mono', 'SFMono-Regular', monospace;

  --wrap: 1240px;
  --gutter: clamp(18px, 4vw, 44px);
  --rail-h: 34px;
  --bar-h: 66px;
  --header-h: 100px;

  --cut-lg: polygon(0 0, calc(100% - 18px) 0, 100% 18px, 100% 100%, 18px 100%, 0 calc(100% - 18px));
  --cut: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 14px 100%, 0 calc(100% - 14px));
  --cut-sm: polygon(0 0, calc(100% - 10px) 0, 100% 10px, 100% 100%, 10px 100%, 0 calc(100% - 10px));
  --cut-corner: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}
@media (max-width: 980px) {
  :root { --rail-h: 30px; --bar-h: 58px; --header-h: 88px; }
}

/* ---------- 基础排版 ---------- */
body {
  background:
    radial-gradient(1200px 620px at 84% -12%, rgba(92, 225, 230, .10), transparent 62%),
    radial-gradient(900px 520px at 4% 2%, rgba(199, 255, 46, .07), transparent 64%),
    linear-gradient(180deg, #071A12 0%, #08170F 45%, #071A12 100%);
  color: var(--snow);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  font-weight: 400;
  letter-spacing: .01em;
  overflow-x: hidden;
}
h1, h2, h3, h4 {
  font-family: var(--font-display);
  line-height: 1.06;
  letter-spacing: .01em;
  font-weight: 600;
  text-wrap: balance;
}
h1 { font-size: clamp(40px, 7.4vw, 112px); font-weight: 200; letter-spacing: -.012em; margin-bottom: .28em; }
h2 { font-size: clamp(28px, 4vw, 52px); font-weight: 500; margin-bottom: .5em; }
h3 { font-size: clamp(19px, 2vw, 24px); font-weight: 600; margin-bottom: .5em; }
p { margin-bottom: 1em; }
p:last-child { margin-bottom: 0; }
a { color: var(--lime); text-decoration: none; }
strong { font-weight: 700; color: var(--snow); }
::selection { background: var(--lime); color: #06170F; }
:focus-visible { outline: 2px solid var(--lime); outline-offset: 3px; border-radius: 2px; }

/* ---------- 工具类 ---------- */
.wrap { width: min(100% - var(--gutter) * 2, var(--wrap)); margin-inline: auto; }
.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;
}
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; letter-spacing: .02em; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 10px; margin: 0 0 14px;
  font-family: var(--font-mono); font-size: 11.5px; letter-spacing: .22em;
  text-transform: uppercase; color: var(--lime);
}
.eyebrow::before { content: ""; width: 26px; height: 1px; background: var(--lime); }
.lede { font-size: clamp(17px, 1.6vw, 20px); color: rgba(242, 255, 247, .82); max-width: 62ch; }
.flow > * + * { margin-top: 1.15em; }
.rule { height: 1px; background: var(--line); border: 0; margin: 0; }

/* ---------- skip link ---------- */
.skip-link {
  position: fixed; left: var(--gutter); top: -120px; z-index: 300;
  padding: 11px 20px; background: var(--lime); color: #06170F;
  font-weight: 700; font-size: 14px; letter-spacing: .04em;
  clip-path: var(--cut-sm); transition: top .18s ease;
}
.skip-link:focus { top: 12px; }

/* ---------- 头部：双层信息导航 ---------- */
.site-header {
  position: sticky; top: 0; z-index: 120;
  background: rgba(7, 26, 18, .92);
  -webkit-backdrop-filter: blur(14px) saturate(130%);
  backdrop-filter: blur(14px) saturate(130%);
  border-bottom: 1px solid var(--line);
}
.header-rail {
  height: var(--rail-h);
  display: flex; align-items: center;
  background: linear-gradient(90deg, rgba(199, 255, 46, .10), rgba(16, 19, 18, .85) 38%, rgba(92, 225, 230, .10));
  border-bottom: 1px solid var(--line-soft);
}
.rail-inner { display: flex; align-items: center; gap: clamp(10px, 2vw, 26px); font-size: 12.5px; }
.rail-line { display: inline-flex; align-items: center; gap: 8px; color: var(--snow); font-weight: 600; letter-spacing: .06em; white-space: nowrap; }
.rail-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--lime); box-shadow: 0 0 10px var(--lime); }
.rail-label {
  font-family: var(--font-mono); font-size: 11px; letter-spacing: .18em; text-transform: uppercase;
  color: var(--mist); border: 1px solid var(--line); padding: 1px 8px; clip-path: var(--cut-sm);
}
.rail-tagline { color: var(--mist); letter-spacing: .03em; }
.rail-meta { margin-left: auto; color: var(--electro); font-size: 11.5px; letter-spacing: .12em; }

.header-main { position: relative; }
.header-inner {
  display: flex; align-items: center; gap: clamp(14px, 3vw, 36px);
  min-height: var(--bar-h); padding-block: 8px;
}
.brand { display: inline-flex; align-items: center; gap: 12px; flex: 0 0 auto; color: var(--snow); }
.brand-mark {
  width: 40px; height: 40px; display: grid; place-items: center;
  font-family: var(--font-display); font-weight: 700; font-size: 24px; line-height: 1;
  color: #06170F; background: linear-gradient(150deg, var(--lime), #8FE000);
  clip-path: polygon(0 0, 100% 0, 100% 72%, 72% 100%, 0 100%);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.1; }
.brand-name { font-family: var(--font-display); font-size: 20px; font-weight: 600; letter-spacing: .08em; }
.brand-sub { font-family: var(--font-mono); font-size: 10.5px; letter-spacing: .22em; color: var(--mist); }

.site-nav { display: flex; align-items: center; gap: clamp(12px, 2vw, 26px); margin-left: auto; }
.nav-head { display: none; }
.nav-list { display: flex; align-items: center; gap: clamp(4px, 1.2vw, 16px); counter-reset: nav; }
.nav-list > li { counter-increment: nav; position: relative; }
.nav-link {
  position: relative; display: block; padding: 17px 9px 11px;
  color: var(--snow); font-size: 15px; font-weight: 500; letter-spacing: .02em;
  transition: color .2s ease;
}
.nav-link::before {
  content: counter(nav, decimal-leading-zero);
  position: absolute; top: 5px; left: 9px;
  font-family: var(--font-mono); font-size: 9.5px; letter-spacing: .08em; color: var(--mist);
  transition: color .2s ease;
}
.nav-link::after {
  content: ""; position: absolute; left: 9px; right: 9px; bottom: 6px; height: 2px;
  background: var(--lime); transform: scaleX(0); transform-origin: left;
  transition: transform .28s cubic-bezier(.2, .7, .2, 1);
}
.nav-link:hover { color: var(--lime); }
.nav-link:hover::after, .nav-link:focus-visible::after { transform: scaleX(1); }
.nav-link[aria-current="page"] { color: var(--lime); }
.nav-link[aria-current="page"]::after { transform: scaleX(1); }
.nav-link[aria-current="page"]::before { color: var(--lime); }
.nav-foot { display: flex; align-items: center; gap: 14px; }
.nav-cta { white-space: nowrap; }

.nav-toggle {
  display: none; flex-direction: column; justify-content: center; gap: 5px;
  width: 46px; height: 42px; padding: 0 11px; cursor: pointer;
  background: transparent; border: 1px solid var(--line-strong); color: var(--snow);
  clip-path: var(--cut-sm); transition: border-color .2s ease, color .2s ease;
}
.nav-toggle:hover { border-color: var(--lime); color: var(--lime); }
.nav-toggle-bar { display: block; height: 2px; background: currentColor; transition: transform .24s ease, opacity .18s ease; }
.site-header[data-open="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.site-header[data-open="true"] .nav-toggle-bar:nth-child(2) { opacity: 0; }
.site-header[data-open="true"] .nav-toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.scroll-progress {
  position: absolute; left: 0; right: 0; bottom: -1px; height: 2px;
  background: linear-gradient(90deg, var(--lime), var(--electro));
  transform: scaleX(var(--p, 0)); transform-origin: 0 50%;
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 12px 20px; border: 1px solid transparent; cursor: pointer;
  font-family: var(--font-body); font-size: 14px; font-weight: 700; letter-spacing: .05em;
  clip-path: var(--cut-sm); transition: background .2s ease, color .2s ease, border-color .2s ease;
}
.btn--lime { background: var(--lime); color: #06170F; }
.btn--lime:hover { background: var(--snow); }
.btn--ghost { background: transparent; border-color: var(--line-strong); color: var(--snow); }
.btn--ghost:hover { border-color: var(--lime); color: var(--lime); }
.btn--orange { background: var(--orange); color: #1B0D02; }
.btn--orange:hover { background: var(--snow); }
.btn--sm { padding: 9px 14px; font-size: 13px; }

/* ---------- 面包屑 ---------- */
.crumbs { padding-block: 16px; font-family: var(--font-mono); font-size: 12px; letter-spacing: .06em; color: var(--mist); }
.crumbs ol { display: flex; flex-wrap: wrap; gap: 8px; }
.crumbs li + li::before { content: "/"; margin-right: 8px; color: rgba(140, 167, 155, .5); }
.crumbs a { color: var(--mist); transition: color .2s ease; }
.crumbs a:hover { color: var(--lime); }
.crumbs [aria-current="page"] { color: var(--lime); }

/* ---------- 章节骨架 ---------- */
.section { padding-block: clamp(44px, 6.5vw, 100px); }
.section--tight { padding-block: clamp(28px, 4vw, 58px); }
.section--band {
  background: linear-gradient(180deg, rgba(20, 43, 34, .55), rgba(7, 26, 18, .1));
  border-top: 1px solid var(--line-soft); border-bottom: 1px solid var(--line-soft);
}
.section-head {
  display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between;
  gap: 18px; padding-bottom: 16px; margin-bottom: clamp(22px, 3vw, 40px);
  border-bottom: 1px solid var(--line);
}
.section-head h2 { margin-bottom: 0; }
.section-note { max-width: 44ch; font-size: 15px; color: var(--mist); }

/* ---------- 网格 ---------- */
.grid { display: grid; gap: clamp(16px, 2.4vw, 28px); }
.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--rail { grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr); }

/* ---------- 切角面板 ---------- */
.panel {
  position: relative; padding: clamp(18px, 2.4vw, 30px);
  background: linear-gradient(160deg, rgba(20, 43, 34, .92), rgba(10, 26, 18, .9));
  border: 1px solid var(--line); clip-path: var(--cut);
  transition: border-color .22s ease, background .22s ease;
}
.panel:hover { border-color: var(--line-strong); background: linear-gradient(160deg, rgba(24, 52, 40, .95), rgba(11, 30, 22, .92)); }
.panel--edge::before { content: ""; position: absolute; left: 0; top: 0; bottom: 0; width: 3px; background: var(--lime); }
.panel--corner { clip-path: var(--cut-corner); }

/* ---------- 标签 ---------- */
.tag {
  display: inline-flex; align-items: center; gap: 6px; padding: 4px 9px;
  border: 1px solid var(--line); color: var(--mist);
  font-family: var(--font-mono); font-size: 11px; letter-spacing: .14em; text-transform: uppercase;
}
a.tag:hover { border-color: var(--lime); color: var(--lime); }
.tag--lime { color: var(--lime); border-color: rgba(199, 255, 46, .5); background: var(--lime-wash); }
.tag--orange { color: var(--orange); border-color: rgba(255, 138, 61, .5); background: var(--orange-wash); }
.tag--electro { color: var(--electro); border-color: rgba(92, 225, 230, .5); background: rgba(92, 225, 230, .08); }
.tag--violet { color: var(--violet); border-color: rgba(182, 156, 255, .5); background: rgba(182, 156, 255, .08); }

/* ---------- 统计条 ---------- */
.stat-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 0 clamp(14px, 2vw, 28px); }
.stat { display: flex; flex-direction: column; gap: 5px; padding: 14px 0; border-top: 1px solid var(--line); }
.stat-value { font-family: var(--font-mono); font-weight: 700; font-size: clamp(24px, 3.4vw, 38px); line-height: 1; letter-spacing: -.02em; color: var(--lime); transition: color .2s ease; }
.stat-label { font-size: 12.5px; color: var(--mist); letter-spacing: .06em; }
.stat:hover .stat-value { color: var(--snow); }
.stat--orange .stat-value { color: var(--orange); }
.stat--electro .stat-value { color: var(--electro); }

/* ---------- 数据表 ---------- */
.data-table { width: 100%; font-size: 14px; }
.data-table caption { padding-bottom: 10px; text-align: left; font-family: var(--font-mono); font-size: 11px; letter-spacing: .18em; text-transform: uppercase; color: var(--mist); }
.data-table th, .data-table td { padding: 11px 12px; text-align: left; border-bottom: 1px solid var(--line-soft); }
.data-table th { font-family: var(--font-mono); font-size: 11px; font-weight: 500; letter-spacing: .14em; text-transform: uppercase; color: var(--mist); }
.data-table td { font-family: var(--font-mono); font-size: 13.5px; color: var(--snow); }
.data-table .is-num { text-align: right; color: var(--lime); }
.data-table tbody tr:hover { background: var(--lime-wash); }

/* ---------- 目录索引 ---------- */
.index-list { border-top: 1px solid var(--line); }
.index-item { border-bottom: 1px solid var(--line); }
.index-link {
  display: grid; grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: baseline; gap: clamp(12px, 2vw, 26px);
  padding: 16px 6px; color: var(--snow);
  transition: background .2s ease, color .2s ease, padding-left .2s ease;
}
.index-link:hover { background: var(--lime-wash); color: var(--lime); padding-left: 14px; }
.index-num { font-family: var(--font-mono); font-size: 12px; letter-spacing: .1em; color: var(--mist); }
.index-title { font-family: var(--font-display); font-size: clamp(18px, 2.2vw, 26px); font-weight: 500; }
.index-meta { font-family: var(--font-mono); font-size: 12px; letter-spacing: .06em; color: var(--mist); }

/* ---------- 锚点目录 ---------- */
.toc { padding: clamp(16px, 2vw, 24px); background: rgba(11, 30, 22, .55); border: 1px solid var(--line); clip-path: var(--cut); }
.toc-title { margin: 0 0 12px; font-family: var(--font-mono); font-size: 11px; letter-spacing: .2em; text-transform: uppercase; color: var(--lime); font-weight: 500; }
.toc-list { counter-reset: toc; }
.toc-list li { counter-increment: toc; }
.toc-list a {
  position: relative; display: block; padding: 8px 0 8px 28px;
  border-bottom: 1px solid var(--line-soft);
  font-size: 14px; color: var(--mist); transition: color .2s ease, padding-left .2s ease;
}
.toc-list a::before { content: counter(toc, decimal-leading-zero); position: absolute; left: 0; font-family: var(--font-mono); font-size: 10.5px; letter-spacing: .06em; color: var(--electro); }
.toc-list a:hover, .toc-list a.is-active, .toc-list a[aria-current] { color: var(--lime); padding-left: 34px; }

/* ---------- 图片容器（页面阶段放置图片） ---------- */
.media {
  position: relative; display: block; width: 100%; overflow: hidden;
  background: linear-gradient(140deg, #0D2218, #142B22 55%, #0A1A12);
  border: 1px solid var(--line); clip-path: var(--cut);
}
.media::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background:
    linear-gradient(90deg, transparent calc(50% - 1px), rgba(199, 255, 46, .16) calc(50% - 1px) calc(50% + 1px), transparent calc(50% + 1px)),
    linear-gradient(0deg, transparent calc(50% - 1px), rgba(199, 255, 46, .16) calc(50% - 1px) calc(50% + 1px), transparent calc(50% + 1px));
}
.media img { width: 100%; height: 100%; object-fit: cover; }
.media--21x9 { aspect-ratio: 21 / 9; }
.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--1x1 { aspect-ratio: 1 / 1; }
.media--3x4 { aspect-ratio: 3 / 4; }
.media--tall { min-height: clamp(240px, 42vw, 520px); }
.media--grain::after {
  content: ""; position: absolute; inset: 0; pointer-events: none; mix-blend-mode: overlay;
  background-image: repeating-linear-gradient(0deg, rgba(255, 255, 255, .04) 0 1px, transparent 1px 3px);
}
.media-figure { margin: 0; }
.media-caption { margin-top: 10px; font-family: var(--font-mono); font-size: 12px; letter-spacing: .04em; color: var(--mist); }

/* ---------- 显现动画 ---------- */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .5s ease, transform .5s cubic-bezier(.2, .7, .2, 1); }
.reveal.is-in { opacity: 1; transform: none; }

/* ---------- 页脚 ---------- */
.site-footer {
  position: relative; overflow: hidden; margin-top: clamp(48px, 7vw, 110px);
  background: linear-gradient(180deg, #0A1712, #060F0C 70%, #050B09);
  border-top: 1px solid var(--line);
}
.site-footer::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: linear-gradient(90deg, var(--lime), rgba(199, 255, 46, 0) 38%, rgba(92, 225, 230, .7) 64%, rgba(182, 156, 255, .6));
}
.footer-glow {
  position: absolute; top: -150px; right: -120px; width: 520px; height: 520px; pointer-events: none;
  background: radial-gradient(circle, rgba(92, 225, 230, .16), transparent 66%);
}
.footer-inner {
  position: relative; display: grid; gap: clamp(24px, 4vw, 56px);
  grid-template-columns: minmax(0, 1.5fr) minmax(0, 1.9fr) minmax(0, 1.4fr);
  padding-block: clamp(40px, 5.5vw, 80px);
}
.footer-eyebrow { margin: 0 0 10px; font-family: var(--font-mono); font-size: 11px; letter-spacing: .22em; text-transform: uppercase; color: var(--lime); }
.footer-brand-line { font-family: var(--font-display); font-size: clamp(26px, 3.4vw, 40px); font-weight: 600; letter-spacing: .05em; margin-bottom: 12px; }
.footer-summary { max-width: 34ch; font-size: 15px; color: rgba(242, 255, 247, .78); }
.footer-region {
  max-width: 38ch; margin-top: 16px; padding-left: 12px;
  border-left: 2px solid rgba(199, 255, 46, .4);
  font-size: 13px; color: var(--mist);
}
.footer-nav { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: clamp(18px, 3vw, 36px); }
.footer-col-title { margin-bottom: 14px; font-family: var(--font-mono); font-size: 11.5px; font-weight: 500; letter-spacing: .2em; text-transform: uppercase; color: var(--lime); }
.footer-links { display: grid; gap: 9px; }
.footer-link { position: relative; display: inline-block; padding-bottom: 2px; font-size: 15px; color: rgba(242, 255, 247, .8); transition: color .2s ease; }
.footer-link::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 1px;
  background: var(--lime); transform: scaleX(0); transform-origin: left; transition: transform .25s ease;
}
.footer-link:hover { color: var(--lime); }
.footer-link:hover::after { transform: scaleX(1); }

.contact-list { display: grid; gap: 12px; }
.contact-item {
  display: flex; flex-wrap: wrap; align-items: center; gap: 6px 10px;
  padding: 10px 12px; background: rgba(7, 26, 18, .55);
  border: 1px solid var(--line); clip-path: var(--cut-sm);
}
.contact-key { font-family: var(--font-mono); font-size: 10.5px; letter-spacing: .16em; text-transform: uppercase; color: var(--mist); min-width: 34px; }
.contact-value { font-family: var(--font-mono); font-size: 13.5px; color: var(--snow); word-break: break-all; }
.contact-text { flex: 1 1 100%; font-size: 14px; line-height: 1.5; color: rgba(242, 255, 247, .85); }
.copy-btn {
  margin-left: auto; padding: 4px 9px; cursor: pointer; background: transparent;
  border: 1px solid var(--line-strong); color: var(--lime);
  font-family: var(--font-mono); font-size: 11px; letter-spacing: .1em;
  transition: background .2s ease, color .2s ease, border-color .2s ease;
}
.copy-btn:hover { background: var(--lime); color: #06170F; }
.copy-btn[data-copy-state="done"] { background: var(--lime); color: #06170F; }
.copy-btn[data-copy-state="fail"] { border-color: var(--orange); color: var(--orange); }
.contact-note { margin-top: 14px; max-width: 36ch; font-size: 12.5px; color: var(--mist); }

.footer-bottom {
  position: relative; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
  gap: 10px 24px; padding-block: 18px 26px;
  border-top: 1px solid var(--line); font-size: 12.5px; color: var(--mist);
}
.footer-legal { font-family: var(--font-mono); letter-spacing: .04em; }
.footer-route { font-family: var(--font-mono); font-size: 11.5px; letter-spacing: .08em; color: rgba(140, 167, 155, .8); }

/* ---------- 响应式 ---------- */
@media (max-width: 1080px) {
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--rail { grid-template-columns: minmax(0, 1.3fr) minmax(0, 1fr); }
  .footer-inner { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .footer-contact { grid-column: 1 / -1; }
}
@media (max-width: 980px) {
  .rail-tagline, .rail-meta { display: none; }
  .header-inner { gap: 14px; }
  .nav-toggle { display: flex; margin-left: auto; }
  .site-nav {
    position: fixed; top: var(--header-h); left: 0; right: 0; margin: 0;
    display: flex; flex-direction: column; align-items: stretch; gap: 0;
    max-height: calc(100vh - var(--header-h)); overflow-y: auto;
    padding: 18px var(--gutter) 28px;
    background: linear-gradient(180deg, rgba(16, 19, 18, .99), rgba(7, 26, 18, .99));
    border-bottom: 1px solid var(--line-strong);
    transform: translateY(-12px); opacity: 0; visibility: hidden; pointer-events: none;
    transition: opacity .22s ease, transform .22s ease, visibility .22s ease;
  }
  .site-nav[data-open="true"] { opacity: 1; visibility: visible; pointer-events: auto; transform: none; }
  .nav-head {
    display: block; margin: 0 0 10px;
    font-family: var(--font-mono); font-size: 11px; letter-spacing: .22em; text-transform: uppercase; color: var(--mist);
  }
  .nav-list { flex-direction: column; align-items: stretch; gap: 0; border-top: 1px solid var(--line); }
  .nav-list > li { border-bottom: 1px solid var(--line); }
  .nav-link { padding: 15px 4px 15px 42px; font-family: var(--font-display); font-size: 17px; font-weight: 500; letter-spacing: .05em; }
  .nav-link::before { top: 50%; left: 6px; transform: translateY(-50%); font-size: 11px; }
  .nav-link::after { display: none; }
  .nav-link[aria-current="page"] { background: var(--lime-wash); }
  .nav-foot { flex-direction: column; align-items: stretch; margin-top: 18px; }
  .nav-cta { width: 100%; padding: 14px 18px; font-size: 15px; }
  .grid--3, .grid--rail { grid-template-columns: minmax(0, 1fr); }
}
@media (max-width: 720px) {
  body { font-size: 16px; }
  .grid--2, .grid--4 { grid-template-columns: minmax(0, 1fr); }
  .index-link { grid-template-columns: auto minmax(0, 1fr); }
  .index-meta { grid-column: 2; }
  .footer-inner { grid-template-columns: minmax(0, 1fr); gap: 30px; }
  .footer-nav { gap: 26px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}

/* ---------- 无障碍：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;
  }
  .reveal { opacity: 1; transform: none; }
  .scroll-progress { transition: none; }
}