/* =========================================================
   亿动赛场 · 共享样式表 /assets/site.css
   深空蓝近单色体系 + 荧光绿 / 活力橙双高亮
   ========================================================= */

*, *::before, *::after { box-sizing: border-box; }

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

body, h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd { margin: 0; padding: 0; }
ul, ol { list-style: none; }
img, svg, video, canvas { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
main { display: block; }

:root {
  /* 色板 */
  --ink-900: #0A1128;
  --ink-850: #0C1430;
  --ink-800: #101B3A;
  --ink-700: #16244D;
  --teal: #0F2A2E;
  --mute: #8A94A6;
  --white: #F5F7FA;
  --neon: #39FF88;
  --orange: #FF6B35;
  --elec: #3B82F6;

  /* 语义层 */
  --text: rgba(245, 247, 250, 0.84);
  --text-dim: rgba(138, 148, 166, 0.96);
  --line: rgba(138, 148, 166, 0.20);
  --line-strong: rgba(138, 148, 166, 0.38);
  --neon-dim: rgba(57, 255, 136, 0.14);
  --orange-dim: rgba(255, 107, 53, 0.14);
  --elec-dim: rgba(59, 130, 246, 0.16);
  --shadow: 0 18px 46px rgba(3, 7, 20, 0.55);

  /* 字体 */
  --mono: ui-monospace, "JetBrains Mono", "Roboto Mono", SFMono-Regular, Menlo, Consolas, "Courier New", monospace;
  --sans: "PingFang SC", "Hiragino Sans GB", "Source Han Sans SC", "Noto Sans SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;

  /* 尺度 */
  --r-xl: 26px;
  --r-l: 18px;
  --r-m: 12px;
  --r-s: 8px;
  --wrap: 1280px;
  --pad: clamp(18px, 4vw, 44px);
  --hdr-h: 78px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

body {
  min-height: 100vh;
  background-color: var(--ink-900);
  background-image:
    radial-gradient(1100px 560px at 88% -8%, rgba(57, 255, 136, 0.10), transparent 62%),
    radial-gradient(880px 540px at 2% 14%, rgba(59, 130, 246, 0.13), transparent 66%),
    repeating-linear-gradient(118deg, rgba(138, 148, 166, 0.05) 0 1px, transparent 1px 96px);
  background-attachment: fixed;
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.78;
  font-weight: 400;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
  color: var(--white);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.02em;
}
h1 { font-size: clamp(2.75rem, 5.6vw, 4.5rem); font-weight: 900; letter-spacing: -0.035em; }
h2 { font-size: clamp(1.75rem, 3.4vw, 2.5rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.55rem); }
h4 { font-size: 1.05rem; }

::selection { background: var(--neon); color: #04160C; }

:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 3px;
  border-radius: 4px;
}

#main-content { display: block; }
[data-section] { scroll-margin-top: calc(var(--hdr-h) + 20px); }

/* ---------- 跳转链接 ---------- */
.skip-link {
  position: absolute;
  left: var(--pad);
  top: 8px;
  z-index: 120;
  transform: translateY(-260%);
  padding: 10px 20px;
  border-radius: 999px;
  background: var(--neon);
  color: #04160C;
  font-size: 14px;
  font-weight: 700;
  transition: transform 0.22s var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* =========================================================
   头部
   ========================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: rgba(10, 17, 40, 0.90);
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.hdr-inner {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.2vw, 34px);
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--pad);
  min-height: var(--hdr-h);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  flex: 0 0 auto;
  color: var(--white);
}
.brand__mark {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 3px;
  width: 36px;
  height: 36px;
  padding: 7px;
  border: 1px solid var(--line-strong);
  border-radius: 11px;
  background: linear-gradient(155deg, rgba(57, 255, 136, 0.16), rgba(59, 130, 246, 0.10));
}
.brand__mark i {
  display: block;
  flex: 1;
  border-radius: 2px;
  background: var(--neon);
  transition: height 0.24s var(--ease);
}
.brand__mark i:nth-child(1) { height: 38%; background: var(--elec); opacity: 0.8; }
.brand__mark i:nth-child(2) { height: 66%; opacity: 0.86; }
.brand__mark i:nth-child(3) { height: 100%; }
.brand:hover .brand__mark i:nth-child(1) { height: 60%; }
.brand:hover .brand__mark i:nth-child(2) { height: 84%; }

.brand__text { display: flex; flex-direction: column; line-height: 1.1; }
.brand__name { font-size: 17px; font-weight: 800; letter-spacing: 0.08em; }
.brand__tag {
  margin-top: 3px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  color: var(--mute);
}

/* 赛季区间刻度尺（装饰） */
.season-rail {
  display: flex;
  align-items: center;
  gap: 14px;
  flex: 1 1 auto;
  min-width: 0;
  overflow: hidden;
  margin-left: 4px;
  padding-left: clamp(6px, 1.4vw, 20px);
  border-left: 1px solid var(--line);
}
.season-rail__label {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.2em;
  color: var(--mute);
  white-space: nowrap;
}
.season-rail__list { display: flex; align-items: flex-end; gap: clamp(8px, 1.6vw, 22px); min-width: 0; }
.season-rail__item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 5px;
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--mute);
  transition: color 0.2s var(--ease);
}
.season-rail__tick {
  display: block;
  width: 2px;
  height: 12px;
  border-radius: 2px;
  background: var(--line-strong);
  transition: height 0.22s var(--ease), background-color 0.22s var(--ease);
}
.season-rail__item:nth-child(2n) .season-rail__tick { height: 18px; }
.season-rail__item:nth-child(3n) .season-rail__tick { height: 8px; background: rgba(59, 130, 246, 0.55); }
.season-rail__item:hover { color: var(--neon); }
.season-rail__item:hover .season-rail__tick { height: 22px; background: var(--neon); }

/* 导航 */
.nav {
  display: none;
  align-items: center;
  gap: clamp(4px, 1vw, 10px);
  flex: 0 0 auto;
}
.nav__list { display: flex; align-items: center; gap: clamp(2px, 0.8vw, 8px); }
.nav__item { display: block; }
.nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 9px 10px;
  border-radius: 10px;
  color: var(--text);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  transition: color 0.2s var(--ease), background-color 0.2s var(--ease);
}
.nav__idx {
  font-family: var(--mono);
  font-size: 10.5px;
  letter-spacing: 0.06em;
  color: var(--mute);
  transition: color 0.2s var(--ease);
}
.nav__label { display: inline-block; }
.nav__link:hover { color: var(--white); background: rgba(22, 36, 77, 0.6); }
.nav__link:hover .nav__idx { color: var(--neon); }
.nav__link[aria-current="page"] { color: var(--neon); }
.nav__link[aria-current="page"] .nav__idx { color: var(--neon); }
.nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 10px;
  right: 10px;
  bottom: 2px;
  height: 2px;
  border-radius: 2px;
  background: var(--neon);
}
.nav__cta { margin-left: 6px; padding: 11px 18px; font-size: 14px; }

/* 汉堡按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  margin-left: auto;
  padding: 10px 15px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: rgba(16, 27, 58, 0.72);
  color: var(--white);
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}
.nav-toggle:hover { border-color: var(--neon); }
.nav-toggle__bars { display: flex; flex-direction: column; gap: 4px; width: 18px; }
.nav-toggle__bar {
  display: block;
  height: 2px;
  width: 100%;
  border-radius: 2px;
  background: var(--neon);
  transition: transform 0.22s var(--ease), opacity 0.22s var(--ease);
}
.nav-toggle__text { line-height: 1; }

.site-header[data-open="true"] .nav-toggle { border-color: var(--neon); color: var(--neon); }
.site-header[data-open="true"] .nav-toggle__bar:first-child { transform: translateY(3px) rotate(45deg); }
.site-header[data-open="true"] .nav-toggle__bar:last-child { transform: translateY(-3px) rotate(-45deg); }

/* 顶部阅读进度 */
.hdr-track {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: rgba(138, 148, 166, 0.14);
  pointer-events: none;
}
.hdr-track::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, var(--elec), var(--neon));
  transform: scaleX(var(--read, 0));
  transform-origin: 0 50%;
  transition: transform 0.1s linear;
}

/* =========================================================
   通用版式
   ========================================================= */
.container {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--pad);
}

.section { padding-block: clamp(52px, 7vw, 96px); }
.section--tight { padding-block: clamp(34px, 4.4vw, 58px); }

.section__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px 22px;
  margin-bottom: clamp(20px, 3vw, 38px);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--neon);
}
.eyebrow::before {
  content: "";
  display: inline-block;
  width: 22px;
  height: 2px;
  background: var(--neon);
}

.divider {
  height: 1px;
  border: 0;
  margin-block: clamp(28px, 4vw, 52px);
  background: linear-gradient(90deg, var(--line-strong), transparent);
}

.prose { max-width: 68ch; }
.prose > p { margin-bottom: 1.05em; }
.prose > p:last-child { margin-bottom: 0; }
.prose h2, .prose h3 { margin-top: 1.6em; margin-bottom: 0.5em; }

/* 侧边导览式布局 */
.with-rail {
  display: grid;
  grid-template-columns: 200px minmax(0, 1fr);
  gap: clamp(20px, 3vw, 52px);
  align-items: start;
}
.with-rail__aside { position: sticky; top: calc(var(--hdr-h) + 26px); }
.with-rail__body { min-width: 0; }

.section-nav { font-family: var(--mono); font-size: 12px; letter-spacing: 0.12em; }
.section-nav__list { display: flex; flex-direction: column; gap: 2px; }
.section-nav__link {
  display: block;
  padding: 9px 12px;
  border-left: 2px solid var(--line);
  color: var(--mute);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}
.section-nav__link:hover { color: var(--white); border-color: var(--line-strong); }
.section-nav__link[aria-current="true"] {
  color: var(--neon);
  border-color: var(--neon);
  background: linear-gradient(90deg, var(--neon-dim), transparent);
}

/* 错位内容流 */
.asym {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 40px);
}
.asym__main { grid-column: 1 / span 7; min-width: 0; }
.asym__side { grid-column: 8 / span 5; margin-top: clamp(20px, 5vw, 76px); min-width: 0; }

/* 栅格 */
.grid { display: grid; gap: clamp(16px, 2.2vw, 28px); }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(228px, 1fr)); }
.grid--4 { grid-template-columns: repeat(auto-fit, minmax(176px, 1fr)); }

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
  transition: transform 0.18s var(--ease), background-color 0.18s var(--ease), color 0.18s var(--ease), border-color 0.18s var(--ease), box-shadow 0.18s var(--ease);
}
.btn--primary {
  background: var(--neon);
  color: #04160C;
  box-shadow: 0 10px 26px rgba(57, 255, 136, 0.20);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 14px 34px rgba(57, 255, 136, 0.30); }
.btn--ghost {
  border-color: var(--line-strong);
  background: rgba(22, 36, 77, 0.42);
  color: var(--white);
}
.btn--ghost:hover { border-color: var(--neon); color: var(--neon); }
.btn--quiet {
  padding: 8px 2px;
  border-radius: 0;
  border-bottom: 1px solid var(--line-strong);
  color: var(--text);
}
.btn--quiet:hover { color: var(--neon); border-color: var(--neon); }

/* 资料卡 */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--line);
  border-radius: var(--r-l);
  background: linear-gradient(165deg, rgba(22, 36, 77, 0.62), rgba(16, 27, 58, 0.92));
}
.card--accent::before {
  content: "";
  position: absolute;
  top: 16px;
  bottom: 16px;
  left: 0;
  width: 3px;
  border-radius: 3px;
  background: var(--neon);
}

/* 标签 */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 11px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-dim);
}
.tag--neon { color: var(--neon); border-color: rgba(57, 255, 136, 0.42); background: var(--neon-dim); }
.tag--orange { color: var(--orange); border-color: rgba(255, 107, 53, 0.42); background: var(--orange-dim); }

/* 数据 */
.stat { display: flex; flex-direction: column; gap: 4px; }
.stat__num {
  font-family: var(--mono);
  font-weight: 700;
  font-size: clamp(1.5rem, 2.6vw, 2.5rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--neon);
}
.stat__num--orange { color: var(--orange); }
.stat__label { font-size: 13.5px; line-height: 1.6; color: var(--text-dim); }

/* 图像容器 */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
  border-radius: var(--r-l);
  background: linear-gradient(150deg, var(--ink-700), var(--teal));
}
.media--wide { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 4 / 5; }
.media > img, .media > video, .media > svg, .media > canvas {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media__track {
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(74deg, rgba(57, 255, 136, 0.16) 0 1px, transparent 1px 26px);
  opacity: 0.55;
  pointer-events: none;
}
.media__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(10, 17, 40, 0) 42%, rgba(10, 17, 40, 0.86));
  pointer-events: none;
}
.media__ph {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 14px;
  text-align: center;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: rgba(245, 247, 250, 0.35);
}
.media__tag { position: absolute; left: 14px; bottom: 14px; z-index: 2; }
.media__caption {
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--mute);
}

/* 面包屑 */
.breadcrumb { font-family: var(--mono); font-size: 12.5px; letter-spacing: 0.06em; color: var(--mute); }
.breadcrumb__list { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.breadcrumb__item { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumb__sep { color: rgba(138, 148, 166, 0.5); }
.breadcrumb__link {
  padding-bottom: 1px;
  color: var(--text-dim);
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.breadcrumb__link:hover { color: var(--neon); border-color: var(--neon); }
.breadcrumb__current { color: var(--white); }

/* 工具类 */
.mono { font-family: var(--mono); }
.accent-neon { color: var(--neon); }
.accent-orange { color: var(--orange); }
.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;
}

/* 滚动显现 */
[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}
[data-reveal].is-visible { opacity: 1; transform: none; }

/* =========================================================
   页脚
   ========================================================= */
.site-footer {
  position: relative;
  overflow: hidden;
  margin-top: clamp(48px, 7vw, 110px);
  border-top: 1px solid var(--line-strong);
  background: linear-gradient(180deg, var(--ink-850), var(--ink-900) 72%);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 46%;
  height: 2px;
  background: linear-gradient(90deg, var(--neon), var(--orange), transparent);
}
.site-footer::after {
  content: "";
  position: absolute;
  right: -140px;
  bottom: -170px;
  width: 440px;
  height: 440px;
  border-radius: 50%;
  background: radial-gradient(circle at 40% 40%, rgba(57, 255, 136, 0.13), rgba(10, 17, 40, 0) 68%);
  pointer-events: none;
}

.ftr-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(220px, 1.2fr) minmax(150px, 0.7fr) minmax(260px, 1.1fr);
  gap: clamp(26px, 4vw, 56px);
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(38px, 5vw, 70px) var(--pad) clamp(26px, 3vw, 42px);
}

.ftr-brand { display: flex; flex-direction: column; align-items: flex-start; min-width: 0; }
.brand--footer .brand__name { font-size: 19px; }
.ftr-note { margin-top: 14px; max-width: 34ch; font-size: 14px; line-height: 1.75; color: var(--text-dim); }
.ftr-note--dim {
  margin-top: 6px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--mute);
}

.ftr-col { min-width: 0; }
.ftr-title {
  margin-bottom: 14px;
  font-family: var(--mono);
  font-size: 11.5px;
  font-weight: 600;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--neon);
}
.ftr-list { display: flex; flex-direction: column; gap: 10px; }
.ftr-list__item { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; font-size: 14.5px; }
.ftr-link {
  padding-bottom: 2px;
  color: var(--text);
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.ftr-link:hover { color: var(--neon); border-color: var(--neon); }

.ftr-contact { align-items: baseline; }
.ftr-key {
  flex: 0 0 auto;
  min-width: 34px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mute);
}
.ftr-val {
  font-family: var(--mono);
  font-size: 14px;
  color: var(--white);
  word-break: break-all;
}

.copy-btn {
  padding: 3px 10px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--text-dim);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background-color 0.2s var(--ease);
}
.copy-btn:hover { color: var(--neon); border-color: var(--neon); background: var(--neon-dim); }
.copy-btn.is-done { color: var(--orange); border-color: rgba(255, 107, 53, 0.5); background: var(--orange-dim); }

.ftr-hint {
  min-height: 18px;
  margin-top: 10px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--orange);
}

.ftr-base { position: relative; z-index: 1; border-top: 1px solid var(--line); }
.ftr-base__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 16px var(--pad) 24px;
}
.ftr-copy {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mute);
}
.ftr-icp { color: var(--text-dim); }

.to-top {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 15px;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--text-dim);
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease);
}
.to-top::before { content: "\2191"; color: var(--neon); font-size: 13px; }
.to-top:hover { color: var(--white); border-color: var(--neon); }

/* =========================================================
   响应式
   ========================================================= */
@media (min-width: 901px) {
  .nav { display: flex; }
}

@media (max-width: 1280px) {
  .nav__idx { display: none; }
}

@media (max-width: 1180px) {
  .season-rail { display: none; }
}

@media (max-width: 1024px) {
  .nav__cta { display: none; }
  .with-rail { grid-template-columns: 168px minmax(0, 1fr); }
}

@media (max-width: 900px) {
  :root { --hdr-h: 68px; }

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

  .nav {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    max-height: calc(100vh - var(--hdr-h));
    overflow-y: auto;
    padding: 10px var(--pad) 24px;
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line-strong);
    background: linear-gradient(180deg, var(--ink-800), var(--ink-900));
    box-shadow: var(--shadow);
  }
  .site-header[data-open="true"] .nav { display: flex; }

  .nav__list { flex-direction: column; align-items: stretch; gap: 0; }
  .nav__item { border-bottom: 1px solid var(--line); }
  .nav__item:last-child { border-bottom: 0; }
  .nav__link {
    width: 100%;
    justify-content: flex-start;
    padding: 15px 4px;
    border-radius: 0;
    font-size: 16px;
  }
  .nav__idx { display: inline; }
  .nav__link[aria-current="page"]::after {
    left: 4px;
    right: auto;
    bottom: 10px;
    width: 24px;
  }
  .nav__cta { display: inline-flex; margin: 18px 0 0; }

  .with-rail { grid-template-columns: minmax(0, 1fr); }
  .with-rail__aside { position: static; }
  .section-nav__list { flex-direction: row; flex-wrap: wrap; gap: 6px; }
  .section-nav__link { border-left: 0; border-bottom: 2px solid var(--line); }

  .asym__main, .asym__side { grid-column: 1 / -1; }
  .asym__side { margin-top: 0; }

  .ftr-inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .ftr-brand { grid-column: 1 / -1; }
}

@media (max-width: 620px) {
  .ftr-inner { grid-template-columns: minmax(0, 1fr); }
  .brand__tag { display: none; }
  .ftr-base__inner { flex-direction: column; align-items: flex-start; }
}

/* =========================================================
   动效偏好
   ========================================================= */
@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;
  }
  [data-reveal] { opacity: 1; transform: none; }
  .hdr-track::after { transition: none; }
}