/* =========================================================
   3344体育看台 · /assets/site.css
   共享层：reset、变量、中文排版、头部、页脚、基础组件
   ========================================================= */

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

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

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

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

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

button, input, textarea, select {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
}

button { cursor: pointer; }

a { color: inherit; text-decoration: none; }

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

summary { cursor: pointer; list-style: none; }
summary::-webkit-details-marker { display: none; }

[id] { scroll-margin-top: 120px; }

:focus-visible {
  outline: 3px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

/* ---------- 2. 变量 ---------- */
:root {
  --ink-900: #050B1A;
  --ink-800: #0A1630;
  --ink-700: #12224A;
  --line: #24406F;
  --cyan: #2BE6D6;
  --cyan-soft: #9FF6EE;
  --orange: #FF7A2F;
  --red: #FF3B4E;
  --white: #F4F8FF;
  --muted: #8FA3C8;

  --grad-night: linear-gradient(135deg, #06122B 0%, #0E3A55 55%, rgba(43, 230, 214, 0.35) 100%);
  --grad-lamp: radial-gradient(ellipse at 20% 0%, rgba(43, 230, 214, 0.22), transparent 62%);

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

  --border: 4px solid var(--line);
  --border-thin: 2px solid var(--line);
  --shadow-hard: 8px 8px 0 rgba(36, 64, 111, 0.85);
  --shadow-hard-sm: 4px 4px 0 rgba(36, 64, 111, 0.9);

  --radius-pill: 999px;
  --radius-card: 18px;
  --wrap: 1280px;
  --gutter: 24px;
  --ease: cubic-bezier(0.22, 0.75, 0.25, 1);
}

/* ---------- 3. 中文排版与页面底色 ---------- */
body {
  min-height: 100vh;
  overflow-x: hidden;
  background-color: var(--ink-900);
  background-image: var(--grad-lamp);
  background-repeat: no-repeat;
  background-size: 100% 640px;
  color: var(--white);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.01em;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.01em;
}

.num,
time,
.mono {
  font-family: var(--font-mono);
  font-feature-settings: "tnum" 1;
  font-variant-numeric: tabular-nums;
}

/* ---------- 4. 布局容器 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(40px, 7vw, 88px); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 10px 20px;
  margin-bottom: 26px;
  padding-bottom: 14px;
  border-bottom: var(--border-thin);
}

.grid {
  display: grid;
  gap: 20px;
}
.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)); }
.span-7 { grid-column: span 7; }

@media (max-width: 980px) {
  .grid--3,
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .span-7 { grid-column: span 2; }
}

@media (max-width: 640px) {
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: 1fr; }
  .span-7 { grid-column: span 1; }
}

/* ---------- 5. 头部 ---------- */
.skip-link {
  position: absolute;
  left: 16px;
  top: -80px;
  z-index: 120;
  padding: 10px 18px;
  border-radius: 0 0 12px 12px;
  background: var(--cyan);
  color: #04121F;
  font-weight: 800;
  font-size: 14px;
  transition: top 0.2s var(--ease);
}
.skip-link:focus { top: 0; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  background: linear-gradient(180deg, rgba(5, 11, 26, 0.96) 0%, rgba(5, 11, 26, 0.86) 62%, rgba(5, 11, 26, 0.62) 100%);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(36, 64, 111, 0.7);
  transition: padding 0.25s var(--ease);
}

.header-rail {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding-block: 13px;
  transition: padding 0.25s var(--ease);
}

.site-header[data-scrolled="true"] .header-rail { padding-block: 7px; }

/* 品牌浮岛 */
.brand-island {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 7px 16px 7px 13px;
  border: var(--border-thin);
  border-radius: var(--radius-pill);
  background: var(--ink-800);
  transition: padding 0.25s var(--ease), border-color 0.25s var(--ease);
}
.site-header[data-scrolled="true"] .brand-island { padding: 5px 14px 5px 11px; }

.brand {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 17px;
  letter-spacing: 0.02em;
  color: var(--white);
  white-space: nowrap;
}
.site-header[data-scrolled="true"] .brand { font-size: 15px; }

.brand-dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(43, 230, 214, 0.16), 0 0 14px rgba(43, 230, 214, 0.7);
  flex: none;
}

.brand-tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.24em;
  color: var(--muted);
  border-left: 1px solid var(--line);
  padding-left: 12px;
  white-space: nowrap;
}

/* 栏目胶囊 */
.nav-capsule {
  justify-self: center;
  max-width: 100%;
  padding: 6px;
  border: var(--border-thin);
  border-radius: var(--radius-pill);
  background: rgba(10, 22, 48, 0.9);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-link {
  display: block;
  padding: 9px 15px;
  border-radius: var(--radius-pill);
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
  transition: color 0.2s var(--ease), background-color 0.2s var(--ease);
}

.nav-link:hover {
  color: var(--white);
  background: rgba(43, 230, 214, 0.1);
}

.nav-link[aria-current="page"] {
  background: var(--orange);
  color: #08111F;
}

.site-header[data-scrolled="true"] .nav-link { padding: 7px 13px; }

/* 右侧工具区 */
.header-utility {
  display: flex;
  align-items: center;
  gap: 10px;
}

.sync-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 13px;
  border: 1px dashed var(--line);
  border-radius: var(--radius-pill);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  white-space: nowrap;
  transition: border-color 0.3s var(--ease), color 0.3s var(--ease);
}

.sync-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--muted);
  flex: none;
  transition: background-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.sync-badge[data-sync-day="wed"] {
  border-style: solid;
  border-color: var(--cyan);
  color: var(--cyan-soft);
}
.sync-badge[data-sync-day="wed"] .sync-dot {
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(43, 230, 214, 0.2);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 10px 15px;
  border: var(--border-thin);
  border-radius: var(--radius-pill);
  background: var(--ink-800);
  color: var(--white);
  font-size: 14px;
  font-weight: 700;
}

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 16px;
  height: 2px;
  background: var(--cyan);
}
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  background: var(--cyan);
  transition: transform 0.22s var(--ease);
}
.nav-toggle-bars::before { top: -5px; }
.nav-toggle-bars::after { top: 5px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { transform: translateY(-5px) rotate(-45deg); }

/* 滚动进度 */
.scroll-progress {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  height: 3px;
  transform: scaleX(var(--progress, 0));
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--cyan), var(--orange));
  transition: transform 0.12s linear;
}

/* ---------- 6. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 96px);
  border-top: var(--border);
  background: var(--ink-900);
  overflow: hidden;
}

.footer-sync {
  padding: 18px 0;
  background: var(--grad-night);
  border-bottom: 1px solid var(--line);
}

.sync-summary {
  border: var(--border-thin);
  border-radius: 14px;
  background: rgba(5, 11, 26, 0.6);
  overflow: hidden;
}

.sync-summary > summary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 16px;
  padding: 12px 16px;
  font-size: 14px;
}

.sync-pulse {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  flex: none;
  animation: syncPulse 2.6s infinite;
}

@keyframes syncPulse {
  0%   { box-shadow: 0 0 0 0 rgba(43, 230, 214, 0.45); }
  70%  { box-shadow: 0 0 0 10px rgba(43, 230, 214, 0); }
  100% { box-shadow: 0 0 0 0 rgba(43, 230, 214, 0); }
}

.sync-text {
  font-weight: 700;
  color: var(--white);
  letter-spacing: 0.02em;
}

.sync-status,
.sync-version {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
}

.sync-status { color: var(--cyan-soft); }

.sync-version {
  padding: 2px 9px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  color: var(--muted);
}

.sync-caret {
  margin-left: auto;
  color: var(--orange);
  font-size: 13px;
  font-weight: 700;
}
.sync-caret::after { content: "展开"; }
.sync-summary[open] .sync-caret::after { content: "收起"; }

.sync-body {
  padding: 6px 16px 16px;
  border-top: 1px dashed var(--line);
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.sync-list {
  margin-top: 10px;
  display: grid;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
}
.sync-list li::before {
  content: "▍";
  color: var(--cyan);
  margin-right: 8px;
}

.footer-watermark {
  position: absolute;
  right: -2%;
  bottom: 6%;
  z-index: 0;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(96px, 18vw, 240px);
  line-height: 1;
  letter-spacing: -0.05em;
  color: rgba(43, 230, 214, 0.06);
  pointer-events: none;
  user-select: none;
}

.footer-grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1.5fr repeat(3, minmax(0, 1fr));
  gap: 32px;
  padding-block: clamp(36px, 6vw, 56px) 32px;
}

.footer-brand-name {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 900;
  letter-spacing: 0.02em;
  color: var(--white);
}

.footer-brand-note {
  margin-top: 10px;
  max-width: 30ch;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.footer-col-title {
  margin-bottom: 12px;
  padding-bottom: 10px;
  border-bottom: var(--border-thin);
  font-size: 15px;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: var(--white);
}
.footer-col-title::before {
  content: "";
  display: block;
  width: 22px;
  height: 3px;
  margin-bottom: 10px;
  background: var(--cyan);
}

.footer-links { display: grid; gap: 2px; }

.footer-link {
  display: block;
  padding: 6px 0;
  color: var(--muted);
  font-size: 15px;
  transition: color 0.2s var(--ease), transform 0.2s var(--ease);
}
.footer-link:hover {
  color: var(--cyan);
  transform: translateX(4px);
}

.footer-legal {
  position: relative;
  z-index: 1;
  padding: 20px 0 28px;
  border-top: 1px solid var(--line);
}

.legal-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  color: var(--muted);
  font-size: 13px;
  letter-spacing: 0.04em;
}

.legal-item { line-height: 1.9; }

.legal-key {
  margin-right: 7px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan-soft);
}

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 19px;
  border: var(--border-thin);
  border-radius: var(--radius-pill);
  background: var(--ink-800);
  color: var(--white);
  font-size: 15px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease), border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.btn:hover {
  transform: translateY(-2px);
  border-color: var(--cyan);
  box-shadow: 0 10px 22px rgba(43, 230, 214, 0.16);
}

.btn--primary {
  border-color: transparent;
  background: linear-gradient(135deg, var(--cyan) 0%, #12A9C6 100%);
  color: #04121F;
  box-shadow: var(--shadow-hard-sm);
}
.btn--primary:hover {
  transform: translateY(-2px);
  box-shadow: 3px 3px 0 rgba(36, 64, 111, 0.9);
}

.btn--ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--cyan);
}
.btn--ghost:hover {
  background: rgba(43, 230, 214, 0.08);
  color: var(--cyan-soft);
}

.btn--block { width: 100%; }

/* ---------- 8. 胶囊标签与标签页 ---------- */
.pill-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  width: fit-content;
  max-width: 100%;
  padding: 6px;
  border: var(--border-thin);
  border-radius: var(--radius-pill);
  background: rgba(10, 22, 48, 0.65);
}

.pill-tab {
  padding: 8px 16px;
  border-radius: var(--radius-pill);
  color: var(--muted);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease);
}

.pill-tab:hover { color: var(--white); }

.pill-tab[aria-selected="true"],
.pill-tab[aria-current="true"] {
  background: var(--orange);
  color: #08111F;
}

[data-tabpanel][hidden] { display: none; }

/* ---------- 9. 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-block: 18px;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

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

.breadcrumb[aria-current="page"] { color: var(--white); }

.breadcrumb-sep { color: var(--line); }

/* ---------- 10. 章节与正文 ---------- */
.chapter {
  display: grid;
  grid-template-columns: minmax(72px, auto) minmax(0, 1fr);
  gap: 20px;
  align-items: start;
}

.chapter-num {
  font-family: var(--font-mono);
  font-size: clamp(56px, 7vw, 96px);
  font-weight: 700;
  line-height: 0.82;
  letter-spacing: -0.04em;
  font-variant-numeric: tabular-nums;
  color: rgba(43, 230, 214, 0.22);
}

.chapter-title {
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 800;
  color: var(--white);
}

.side-note {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.24em;
  color: var(--muted);
}

.prose {
  max-width: 68ch;
  font-size: 17px;
  line-height: 1.85;
  color: #DCE6F7;
}
.prose p + p { margin-top: 1em; }
.prose h3 {
  margin-top: 1.6em;
  margin-bottom: 0.5em;
  font-size: 20px;
  font-weight: 800;
  color: var(--white);
}
.prose ul,
.prose ol { margin-top: 0.8em; display: grid; gap: 0.5em; }
.prose li { position: relative; padding-left: 20px; }
.prose li::before {
  content: "—";
  position: absolute;
  left: 0;
  color: var(--cyan);
}
.prose a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 11. 卡片、面板、数据块 ---------- */
.card {
  padding: 22px;
  border: var(--border);
  border-radius: var(--radius-card);
  background: var(--ink-800);
  box-shadow: var(--shadow-hard);
  transition: transform 0.25s var(--ease), box-shadow 0.25s var(--ease), border-color 0.25s var(--ease);
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: 3px 3px 0 rgba(36, 64, 111, 0.9);
  border-color: var(--cyan);
}

.card-title {
  font-size: 20px;
  font-weight: 800;
  color: var(--white);
}

.card-text {
  margin-top: 10px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

.panel {
  padding: 18px;
  border: var(--border-thin);
  border-radius: 14px;
  background: var(--ink-700);
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 14px;
}

.stat {
  padding: 16px;
  border: var(--border-thin);
  border-radius: 14px;
  background: var(--ink-700);
}

.stat-value {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  color: var(--cyan);
}

.stat-label {
  display: block;
  margin-top: 6px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

/* ---------- 12. 图片容器 ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  border: var(--border);
  border-radius: var(--radius-card);
  background: var(--grad-night);
  box-shadow: var(--shadow-hard);
}
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--portrait { aspect-ratio: 4 / 5; }

.media-frame--lamp::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at 20% 0%, rgba(43, 230, 214, 0.22), transparent 62%);
  pointer-events: none;
}

.media-frame figcaption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 28px 14px 10px;
  background: linear-gradient(180deg, transparent, rgba(5, 11, 26, 0.92));
  color: var(--cyan-soft);
  font-size: 13px;
  letter-spacing: 0.04em;
}

/* ---------- 13. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 11px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
}
.tag--cyan {
  border-color: rgba(43, 230, 214, 0.5);
  color: var(--cyan);
}
.tag--orange {
  border-color: rgba(255, 122, 47, 0.55);
  color: var(--orange);
}

/* ---------- 14. 显现动效 ---------- */
html.has-js [data-reveal] {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}
html.has-js [data-reveal="left"] { transform: translateX(-16px); }
html.has-js [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 15. 响应式：头部与页脚 ---------- */
@media (max-width: 1180px) {
  .brand-tag { display: none; }
}

@media (max-width: 1040px) {
  .nav-link { padding: 8px 11px; font-size: 13px; }
  .btn-collect { padding: 10px 14px; font-size: 14px; }
}

@media (max-width: 960px) {
  .header-rail {
    grid-template-columns: 1fr auto;
    gap: 10px;
  }
  .header-utility { justify-self: end; }
  .nav-toggle { display: inline-flex; }

  .nav-capsule {
    position: fixed;
    left: 16px;
    right: 16px;
    bottom: 16px;
    z-index: 90;
    justify-self: stretch;
    max-height: min(72vh, 560px);
    overflow: auto;
    padding: 10px;
    border-radius: 20px;
    border: var(--border-thin);
    background: linear-gradient(160deg, var(--ink-800), var(--ink-900));
    box-shadow: 0 18px 44px rgba(0, 0, 0, 0.6);
    opacity: 0;
    visibility: hidden;
    transform: translateY(24px) scale(0.98);
    transition: opacity 0.28s var(--ease), transform 0.28s var(--ease), visibility 0.28s var(--ease);
  }

  .nav-capsule[data-open="true"] {
    opacity: 1;
    visibility: visible;
    transform: none;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 6px;
  }

  .nav-link {
    padding: 14px 16px;
    border-radius: 14px;
    font-size: 16px;
    text-align: left;
  }

  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px;
  }
  .footer-brand { grid-column: span 2; }
}

@media (max-width: 720px) {
  .sync-badge { padding: 7px 11px; }
  .sync-badge-text { display: none; }
  .btn-collect { padding: 9px 13px; font-size: 13px; }
}

@media (max-width: 600px) {
  :root { --gutter: 18px; }
  .brand-name { font-size: 15px; }
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .footer-brand { grid-column: span 1; }
  .sync-summary > summary { font-size: 13px; }
  .sync-caret { width: 100%; margin-left: 0; }
  .chapter {
    grid-template-columns: 1fr;
    gap: 10px;
  }
  .chapter-num { font-size: clamp(48px, 16vw, 72px); }
}

/* ---------- 16. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  html.has-js [data-reveal],
  html.has-js [data-reveal="left"] {
    opacity: 1;
    transform: none;
  }

  .scroll-progress { transition: none; }
  .card:hover,
  .btn:hover,
  .footer-link:hover { transform: none; }
}