/* =========================================================
   33体育赛场 · /assets/site.css
   目录型内容地图 / 悬浮胶囊浮岛 / 冰面竞技场色彩体系
   ========================================================= */

/* ---------- 1. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; }
h1, h2, h3, h4, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { list-style: none; margin: 0; padding: 0; }
img, picture, video, svg { display: block; max-width: 100%; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }
[hidden] { display: none !important; }

/* ---------- 2. 设计令牌 ---------- */
:root {
  --ink: #070C12;
  --ink-2: #0F1A24;
  --glass: #16242F;
  --paper: #EAF6FC;
  --mist: #9DB4C2;
  --blue: #59C8F5;
  --blue-deep: #1B6E96;
  --neon: #35F0A0;
  --violet: #8E5BFF;
  --steel: #2C3B47;

  --steel-soft: rgba(44, 59, 71, .62);
  --blue-soft: rgba(89, 200, 245, .14);
  --neon-soft: rgba(53, 240, 160, .13);
  --violet-soft: rgba(142, 91, 255, .14);
  --ink-glass: rgba(7, 12, 18, .74);
  --glass-fill: rgba(22, 36, 47, .66);

  --radius-s: 10px;
  --radius: 16px;
  --radius-l: 24px;
  --pill: 999px;
  --shadow: 0 18px 48px rgba(3, 7, 12, .55);

  --font-display: "Barlow Condensed", "Archivo Narrow", "Arial Narrow", "Helvetica Neue", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "Roboto Mono", "DIN Alternate", "SFMono-Regular", ui-monospace, Menlo, Consolas, monospace;
  --font-body: "PingFang SC", "Microsoft YaHei", "Noto Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;

  --ease: cubic-bezier(.22, .61, .36, 1);
  --shell-max: 1240px;
  --progress: 0;
}

/* ---------- 3. 基础排版（中文优先） ---------- */
body {
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  color: var(--paper);
  background-color: var(--ink);
  background-image:
    radial-gradient(900px 520px at 12% -10%, rgba(89, 200, 245, .16), transparent 62%),
    radial-gradient(820px 500px at 94% 2%, rgba(142, 91, 255, .13), transparent 60%),
    linear-gradient(180deg, #070C12 0%, #0A131C 42%, #070C12 100%);
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

h1, h2, h3, .display {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: .98;
  letter-spacing: .012em;
  color: var(--paper);
  text-wrap: balance;
}
h1 { font-size: clamp(2.4rem, 6vw, 5.4rem); }
h2 { font-size: clamp(1.7rem, 3vw, 2.6rem); }
h3 { font-size: clamp(1.1rem, 1.6vw, 1.4rem); }

p { margin: 0 0 1.2em; max-width: 68ch; }
p:last-child { margin-bottom: 0; }

.num, [data-num], .stat__num, .score-card__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .01em;
}

::selection { background: var(--blue); color: #04121B; }

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

.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* ---------- 4. 容器与网格 ---------- */
.shell { width: min(var(--shell-max), 100% - 2.5rem); margin-inline: auto; }
.shell--narrow { width: min(820px, 100% - 2.5rem); margin-inline: auto; }

.page-main { display: block; padding: 2rem 0 4.5rem; }
.section { padding: 3rem 0; }
.section--tight { padding: 1.75rem 0; }

.grid { display: grid; gap: 1.25rem; }
.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--split { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 1.75rem; }

.stack > * + * { margin-top: 1rem; }
.stack--lg > * + * { margin-top: 1.75rem; }

/* ---------- 5. 跳过链接 ---------- */
.skip-link {
  position: fixed;
  top: -120px; left: 1rem;
  z-index: 200;
  padding: .7rem 1.1rem;
  border-radius: var(--radius-s);
  background: var(--blue);
  color: #04121B;
  font-weight: 700;
  font-size: .9rem;
  transition: top 180ms var(--ease);
}
.skip-link:focus { top: 1rem; }

/* ---------- 6. 头部：悬浮胶囊浮岛 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  padding: .85rem 0 .65rem;
  background: linear-gradient(180deg, rgba(7, 12, 18, .92) 0%, rgba(7, 12, 18, .62) 72%, rgba(7, 12, 18, 0) 100%);
}

.header-inner {
  position: relative;
  z-index: 2;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: .5rem .6rem .5rem 1rem;
  border: 1px solid var(--steel-soft);
  border-radius: var(--pill);
  background: var(--glass-fill);
  -webkit-backdrop-filter: blur(16px) saturate(150%);
  backdrop-filter: blur(16px) saturate(150%);
  box-shadow: 0 12px 36px rgba(3, 7, 12, .5);
  transition: padding 240ms var(--ease), background 240ms var(--ease), border-color 240ms var(--ease);
}
.site-header[data-scrolled="true"] .header-inner {
  padding-top: .3rem;
  padding-bottom: .3rem;
  background: rgba(15, 26, 36, .92);
  border-color: rgba(89, 200, 245, .28);
}

.brand { display: flex; align-items: center; gap: .6rem; flex: 0 0 auto; }
.brand__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  padding: .32rem .5rem;
  border-radius: var(--radius-s);
  background: var(--blue);
  color: #04121B;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: .02em;
}
.brand__text { display: flex; flex-direction: column; line-height: 1.15; }
.brand__name {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.18rem;
  letter-spacing: .03em;
  color: var(--paper);
}
.brand__sub { font-size: .68rem; letter-spacing: .14em; color: var(--mist); }

/* 胶囊导航 */
.nav {
  position: relative;
  flex: 1 1 auto;
  display: flex;
  justify-content: center;
  min-width: 0;
}
.nav__list { position: relative; display: flex; gap: .15rem; align-items: center; }
.nav__item { display: block; }
.nav__link {
  position: relative;
  z-index: 1;
  display: block;
  padding: .52rem .8rem;
  border-radius: var(--pill);
  color: var(--mist);
  font-size: .92rem;
  font-weight: 600;
  white-space: nowrap;
  transition: color 180ms var(--ease), background-color 180ms var(--ease);
}
.nav__link:hover { color: var(--paper); background: rgba(89, 200, 245, .08); }
.nav__link[aria-current="page"] { color: var(--paper); }
.nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 50%; bottom: .18rem;
  width: 5px; height: 5px;
  margin-left: -2.5px;
  border-radius: 50%;
  background: var(--neon);
}

.nav__indicator {
  position: absolute;
  top: 0; left: 0;
  width: 0; height: 0;
  border: 1px solid rgba(89, 200, 245, .45);
  border-radius: var(--pill);
  background: var(--blue-soft);
  opacity: 0;
  pointer-events: none;
  transition: transform 220ms var(--ease), width 220ms var(--ease), height 220ms var(--ease), opacity 160ms linear;
}

/* 头部工具区 */
.header-tools { display: flex; align-items: center; gap: .5rem; flex: 0 0 auto; }

.search-chip {
  display: inline-flex;
  align-items: center;
  gap: .45rem;
  min-height: 44px;
  padding: .4rem .85rem;
  border: 1px solid var(--steel);
  border-radius: var(--pill);
  background: rgba(15, 26, 36, .6);
  color: var(--mist);
  font-size: .82rem;
  letter-spacing: .04em;
  transition: color 180ms var(--ease), border-color 180ms var(--ease), background-color 180ms var(--ease);
}
.search-chip:hover { color: var(--paper); border-color: var(--blue); background: var(--blue-soft); }
.search-chip__glyph {
  position: relative;
  width: 12px; height: 12px;
  border: 1.6px solid currentColor;
  border-radius: 50%;
}
.search-chip__glyph::after {
  content: "";
  position: absolute;
  right: -4px; bottom: -3px;
  width: 6px; height: 1.6px;
  border-radius: 2px;
  background: currentColor;
  transform: rotate(45deg);
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  min-height: 44px;
  padding: .58rem 1.15rem;
  border: 1px solid transparent;
  border-radius: var(--pill);
  font-size: .9rem;
  font-weight: 700;
  letter-spacing: .02em;
  white-space: nowrap;
  transition: transform 160ms var(--ease), background-color 180ms var(--ease), color 180ms var(--ease), border-color 180ms var(--ease);
}
.btn--primary {
  background: linear-gradient(135deg, var(--blue) 0%, #8CE0FF 48%, var(--neon) 130%);
  color: #04121B;
}
.btn--primary:hover { transform: translateY(-1px); }
.btn--primary:active { background: var(--blue-deep); color: var(--paper); }
.btn--ghost {
  background: rgba(22, 36, 47, .7);
  border-color: var(--steel);
  color: var(--paper);
}
.btn--ghost:hover { border-color: var(--blue); color: var(--blue); }
.header-cta { padding-inline: 1rem; }

/* 移动端菜单按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px; height: 44px;
  border: 1px solid var(--steel);
  border-radius: var(--pill);
  background: rgba(15, 26, 36, .8);
  color: var(--paper);
  transition: border-color 180ms var(--ease), color 180ms var(--ease);
}
.nav-toggle:hover { border-color: var(--blue); color: var(--blue); }
.nav-toggle__bars {
  position: relative;
  display: block;
  width: 18px; height: 2px;
  border-radius: 2px;
  background: currentColor;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute; left: 0;
  width: 18px; height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 200ms var(--ease), top 200ms var(--ease);
}
.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { top: 0; transform: rotate(-45deg); }
.nav-toggle__label {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

/* 首屏横向比分条 */
.score-strip {
  display: flex;
  align-items: center;
  gap: .8rem;
  margin-top: .55rem;
  padding: .45rem .8rem;
  max-height: 96px;
  overflow: hidden;
  border: 1px solid var(--steel-soft);
  border-radius: var(--radius);
  background: linear-gradient(90deg, rgba(15, 26, 36, .9), rgba(22, 36, 47, .7));
  -webkit-backdrop-filter: blur(14px);
  backdrop-filter: blur(14px);
  transition: max-height 260ms var(--ease), opacity 200ms linear, margin 260ms var(--ease), padding 260ms var(--ease), border-color 260ms var(--ease);
}
.site-header[data-scrolled="true"] .score-strip {
  max-height: 0;
  margin-top: 0;
  padding-top: 0;
  padding-bottom: 0;
  opacity: 0;
  border-color: transparent;
}
.score-strip__tag {
  flex: 0 0 auto;
  padding: .18rem .6rem;
  border: 1px solid rgba(53, 240, 160, .38);
  border-radius: var(--pill);
  background: var(--neon-soft);
  color: var(--neon);
  font-family: var(--font-mono);
  font-size: .72rem;
  letter-spacing: .08em;
}
.score-strip__list {
  flex: 1 1 auto;
  display: flex;
  align-items: center;
  gap: .7rem;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  padding-bottom: 2px;
}
.score-strip__list::-webkit-scrollbar { height: 4px; }
.score-strip__list::-webkit-scrollbar-thumb { background: var(--steel); border-radius: 4px; }

.score-card {
  display: inline-flex;
  align-items: baseline;
  gap: .35rem;
  flex: 0 0 auto;
  scroll-snap-align: start;
  padding: .3rem .7rem;
  border: 1px solid var(--steel);
  border-radius: var(--radius-s);
  background: rgba(7, 12, 18, .62);
  white-space: nowrap;
  transition: border-color 180ms var(--ease), background-color 180ms var(--ease);
}
.score-card:hover,
.score-card:focus-within { border-color: rgba(53, 240, 160, .45); background: rgba(11, 22, 32, .9); }
.score-card__team { font-size: .8rem; color: var(--paper); }
.score-card__num {
  font-size: 1.22rem;
  font-weight: 700;
  line-height: 1;
  color: var(--neon);
}
.score-card__sep { color: var(--mist); font-size: .8rem; }
.score-card__meta {
  margin-left: .35rem;
  padding-left: .5rem;
  border-left: 1px solid var(--steel);
  color: var(--mist);
  font-size: .68rem;
  opacity: .6;
  transition: opacity 200ms var(--ease), color 200ms var(--ease);
}
.score-card:hover .score-card__meta { opacity: 1; color: var(--blue); }

.score-strip__more {
  flex: 0 0 auto;
  color: var(--blue);
  font-size: .78rem;
  padding-bottom: 1px;
  border-bottom: 1px solid rgba(89, 200, 245, .4);
  transition: color 180ms var(--ease), border-color 180ms var(--ease);
}
.score-strip__more:hover { color: var(--neon); border-color: var(--neon); }

/* 滚动进度线 */
.header-progress {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--blue), var(--neon));
  transform: scaleX(var(--progress));
  transform-origin: 0 50%;
  transition: transform 120ms linear;
  opacity: .9;
}

/* ---------- 7. 页脚：品牌手册式目录层 ---------- */
.site-footer {
  margin-top: 3rem;
  padding: 3.25rem 0 1.5rem;
  border-top: 1px solid var(--steel);
  background: linear-gradient(180deg, var(--ink-2) 0%, #0A141C 45%, #070C12 100%);
  color: var(--mist);
  font-size: .9rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr repeat(4, minmax(0, 1fr));
  gap: 2.25rem 1.5rem;
}
.footer-brand { display: grid; gap: .5rem; align-content: start; justify-items: start; }
.footer-brand__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 44px;
  padding: .34rem .6rem;
  border-radius: var(--radius-s);
  background: var(--blue);
  color: #04121B;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 1.05rem;
}
.footer-brand__name {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: .04em;
  color: var(--paper);
}
.footer-brand__desc { margin: 0; font-size: .86rem; color: var(--mist); max-width: 24ch; }
.footer-brand__cta { margin-top: .35rem; }

.footer-col__title {
  font-family: var(--font-mono);
  font-size: .76rem;
  font-weight: 500;
  letter-spacing: .16em;
  color: var(--blue);
  margin-bottom: .75rem;
  padding-bottom: .5rem;
  border-bottom: 1px solid var(--steel);
}
.footer-col__list { display: grid; gap: .2rem; }
.footer-link {
  display: inline-block;
  padding: .18rem 0;
  color: var(--mist);
  font-size: .88rem;
  transition: color 160ms var(--ease), transform 160ms var(--ease);
}
.footer-link:hover { color: var(--paper); transform: translateX(3px); }

.footer-meta {
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--steel);
  display: grid;
  gap: .6rem;
  font-size: .8rem;
  line-height: 1.7;
}
.footer-legal { display: flex; flex-wrap: wrap; gap: 1.25rem; }
.footer-legal .footer-link { font-size: .82rem; color: var(--paper); }
.footer-legal .footer-link:hover { color: var(--blue); }
.footer-meta__contact { margin: 0; color: var(--paper); max-width: 78ch; }
.footer-meta__note { margin: 0; color: var(--mist); max-width: 78ch; }
.footer-meta__icp {
  margin: 0;
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .02em;
  color: var(--mist);
}

/* ---------- 8. 通用基础组件 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .35rem;
  margin: 0 0 1.5rem;
  font-size: .8rem;
  color: var(--mist);
}
.breadcrumb li { display: inline-flex; align-items: center; gap: .35rem; }
.breadcrumb li + li::before { content: "/"; color: var(--steel); }
.breadcrumb a { color: var(--mist); transition: color 160ms var(--ease); }
.breadcrumb a:hover { color: var(--blue); }
.breadcrumb [aria-current="page"] { color: var(--paper); }

.section-head {
  display: grid;
  gap: .55rem;
  margin-bottom: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--steel);
}
.section-head__index {
  font-family: var(--font-mono);
  font-size: .76rem;
  letter-spacing: .16em;
  color: var(--blue);
}
.section-head__title { font-size: clamp(1.55rem, 3vw, 2.4rem); }
.section-head__note { color: var(--mist); font-size: .92rem; max-width: 62ch; }

.card {
  position: relative;
  padding: 1.25rem 1.35rem;
  border: 1px solid var(--steel);
  border-radius: var(--radius);
  background: var(--ink-2);
  transition: border-color 200ms var(--ease), transform 200ms var(--ease);
}
.card:hover { border-color: rgba(89, 200, 245, .4); }
.card--glass {
  background: var(--glass-fill);
  -webkit-backdrop-filter: blur(14px) saturate(150%);
  backdrop-filter: blur(14px) saturate(150%);
}
.card--accent::before {
  content: "";
  position: absolute;
  left: 0; top: 1.1rem; bottom: 1.1rem;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--blue), var(--neon));
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  padding: .2rem .6rem;
  border: 1px solid var(--steel);
  border-radius: var(--pill);
  color: var(--mist);
  font-size: .74rem;
  letter-spacing: .08em;
  white-space: nowrap;
}
.tag--blue { color: var(--blue); border-color: rgba(89, 200, 245, .45); background: var(--blue-soft); }
.tag--neon { color: var(--neon); border-color: rgba(53, 240, 160, .4); background: var(--neon-soft); }
.tag--violet { color: #C4AEFF; border-color: rgba(142, 91, 255, .45); background: var(--violet-soft); }

.stat { display: grid; gap: .2rem; }
.stat__num {
  font-size: clamp(1.6rem, 3.4vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  color: var(--neon);
}
.stat__label { font-size: .78rem; letter-spacing: .1em; color: var(--mist); }

.index-list { border-top: 1px solid var(--steel); }
.index-list__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 1rem;
  align-items: baseline;
  padding: .95rem .25rem;
  border-bottom: 1px solid var(--steel);
  transition: background 200ms var(--ease), padding-left 200ms var(--ease);
}
.index-list__item:hover {
  padding-left: .75rem;
  background: linear-gradient(90deg, rgba(89, 200, 245, .12), transparent 72%);
}
.index-list__num { font-family: var(--font-mono); font-size: .8rem; letter-spacing: .08em; color: var(--blue); }
.index-list__title { font-weight: 700; color: var(--paper); font-size: 1rem; }
.index-list__meta { font-size: .78rem; color: var(--mist); white-space: nowrap; }

.accordion {
  border: 1px solid var(--steel);
  border-radius: var(--radius);
  background: rgba(15, 26, 36, .7);
  padding: 0 .1rem;
}
.accordion + .accordion { margin-top: .75rem; }
.accordion > summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.2rem;
  cursor: pointer;
  font-weight: 600;
  color: var(--paper);
  list-style: none;
}
.accordion > summary::-webkit-details-marker { display: none; }
.accordion > summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--blue);
  transition: transform 200ms var(--ease);
}
.accordion[open] > summary::after { transform: rotate(45deg); }
.accordion__body { padding: 0 1.2rem 1.1rem; color: var(--mist); }

/* 图片容器基础规则（页面阶段放入 img/picture） */
.media {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--steel);
  border-radius: var(--radius);
  aspect-ratio: 16 / 9;
  background: linear-gradient(150deg, #0B1622 0%, #132433 55%, #0B1622 100%);
}
.media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    radial-gradient(120% 90% at 14% 0%, rgba(89, 200, 245, .22), transparent 60%),
    radial-gradient(90% 70% at 92% 100%, rgba(142, 91, 255, .18), transparent 62%),
    repeating-linear-gradient(115deg, rgba(234, 246, 252, .05) 0 2px, transparent 2px 9px);
}
.media img,
.media > picture > img {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media--wide { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 4 / 5; }
.media__caption {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  z-index: 2;
  padding: 1.5rem 1.1rem .9rem;
  background: linear-gradient(180deg, transparent, rgba(7, 12, 18, .88));
  color: var(--paper);
  font-size: .82rem;
}

/* 滚动显现协议 */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 240ms var(--ease), transform 240ms var(--ease);
  transition-delay: calc(var(--reveal-i, 0) * 60ms);
}
.js [data-reveal].is-visible { opacity: 1; transform: none; }

/* ---------- 9. 响应式 ---------- */
@media (max-width: 1180px) {
  .brand__sub { display: none; }
  .nav__link { padding: .5rem .62rem; font-size: .86rem; }
  .header-cta { padding-inline: .85rem; font-size: .85rem; }
}

@media (max-width: 1024px) {
  .grid--3, .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--split { grid-template-columns: minmax(0, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 980px) {
  .site-header { padding-top: .6rem; }
  .header-inner { gap: .5rem; padding: .45rem .55rem .45rem .8rem; }

  .nav {
    position: fixed;
    inset: 0;
    z-index: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 5.5rem 1.25rem 2.5rem;
    background: rgba(7, 12, 18, .97);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity 200ms var(--ease), transform 220ms var(--ease), visibility 200ms linear;
  }
  .nav[data-open="true"] { opacity: 1; visibility: visible; transform: none; }
  .nav__list { flex-direction: column; align-items: stretch; gap: .35rem; width: min(420px, 100%); }
  .nav__link {
    padding: .95rem 1.1rem;
    border: 1px solid transparent;
    border-radius: var(--radius);
    font-size: 1.12rem;
    font-weight: 700;
  }
  .nav__link[aria-current="page"] {
    border-color: rgba(89, 200, 245, .45);
    background: var(--blue-soft);
  }
  .nav__link[aria-current="page"]::after { display: none; }
  .nav__indicator { display: none; }

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

  html.nav-open, html.nav-open body { overflow: hidden; }
}

@media (max-width: 720px) {
  body { font-size: 16px; }
  .shell, .shell--narrow { width: min(var(--shell-max), 100% - 1.75rem); }
  .search-chip__text { display: none; }
  .search-chip { padding-inline: .7rem; }
  .score-strip { gap: .55rem; padding: .4rem .6rem; }
  h1 { font-size: clamp(2.1rem, 9vw, 3.2rem); }
}

@media (max-width: 560px) {
  .header-cta { font-size: .8rem; padding-inline: .7rem; }
  .brand__name { font-size: 1.05rem; }
  .footer-grid { grid-template-columns: minmax(0, 1fr); gap: 1.75rem; }
  .grid--2 { grid-template-columns: minmax(0, 1fr); }
  .index-list__item { grid-template-columns: auto minmax(0, 1fr); }
  .index-list__meta { grid-column: 2; }
}

/* ---------- 10. 无障碍动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .js [data-reveal] { opacity: 1; transform: none; transition: none; }
  .header-progress { transition: none; }
}