/* ============================================================
   开云体育新版 · KAIYUN V4 中文站 共享外壳样式
   /assets/site.css
   午夜蓝同色阶 + 荧光青 / 炽焰橙脉冲 + 1px 精密网格
   ============================================================ */

/* ---------- 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, ul, ol, li, figure, blockquote, dl, dd, hr {
  margin: 0;
  padding: 0;
}

ul, ol { list-style: none; }

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

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

/* ---------- 2. 变量 ---------- */
:root {
  --ink-900: #060A16;
  --ink-800: #0B1226;
  --ink-700: #131E3D;
  --ink-600: #1B2A52;
  --steel: #C6D0E2;
  --text: #F4F7FF;
  --text-soft: #D3DBEC;
  --muted: #8C9AB8;
  --cyan: #00E0C8;
  --orange: #FF6B1F;
  --green: #2BE08A;

  --line: rgba(198, 208, 226, 0.18);
  --line-strong: rgba(198, 208, 226, 0.32);

  --rail-w: clamp(252px, 22vw, 330px);
  --gutter: clamp(20px, 4vw, 56px);
  --step: 8px;

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

  --ease: 220ms cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 3. 中文排版基底 ---------- */
body {
  min-height: 100vh;
  padding-left: var(--rail-w);
  background-color: var(--ink-900);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.85;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

/* 全站网格母题 + 两端色光 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(90deg, rgba(198, 208, 226, 0.05) 1px, transparent 1px),
    linear-gradient(0deg, rgba(198, 208, 226, 0.035) 1px, transparent 1px),
    radial-gradient(120% 85% at 100% 0%, rgba(0, 224, 200, 0.08), transparent 58%),
    radial-gradient(80% 60% at 0% 100%, rgba(255, 107, 31, 0.055), transparent 62%);
  background-size: 88px 88px, 88px 88px, 100% 100%, 100% 100%;
}

main,
.site-foot {
  position: relative;
  z-index: 1;
}

#main-content { scroll-margin-top: 84px; }

h1, h2, h3, h4 {
  font-weight: 800;
  letter-spacing: -0.015em;
  line-height: 1.24;
  text-wrap: balance;
}

h1, .h1 {
  font-size: clamp(2.4rem, 5vw, 4.2rem);
  font-weight: 900;
  line-height: 1.06;
  letter-spacing: -0.02em;
}

h2, .h2 { font-size: 1.9rem; }
h3, .h3 { font-size: 1.3rem; font-weight: 700; line-height: 1.4; }

p { text-wrap: pretty; }

strong, b { font-weight: 700; }

::selection {
  background: rgba(0, 224, 200, 0.28);
  color: var(--text);
}

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

.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;
}

/* ---------- 4. skip link ---------- */
.skip-link {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 200;
  padding: 11px 20px;
  background: var(--orange);
  color: #080C16;
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.02em;
  transform: translateY(-130%);
  transition: transform var(--ease);
}

.skip-link:focus { transform: translateY(0); }

/* ---------- 5. 侧边轨道头部 ---------- */
.site-rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 60;
  width: var(--rail-w);
  background-color: var(--ink-800);
  border-right: 1px solid var(--line);
}

.rail-bar { display: none; }

.rail-inner {
  display: flex;
  flex-direction: column;
  gap: 22px;
  height: 100%;
  padding: 30px 22px 26px;
  overflow-y: auto;
}

.rail-head {
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--line);
}

.brand,
.rail-bar-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-glyph {
  flex: 0 0 42px;
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: #04120F;
  background: linear-gradient(135deg, var(--cyan) 0%, #00B7A4 100%);
  clip-path: polygon(0 0, 100% 0, 100% 74%, 74% 100%, 0 100%);
}

.brand-copy { display: block; }

.brand-name {
  display: block;
  font-size: 17px;
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.3;
}

.brand-sub {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--muted);
  text-transform: uppercase;
}

.rail-bar-name {
  font-size: 15px;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.version-pill {
  align-self: flex-start;
  padding: 4px 10px;
  border: 1px solid rgba(0, 224, 200, 0.42);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  line-height: 1.6;
}

.rail-nav { flex: 1 1 auto; }

.rail-nav-title {
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  color: var(--muted);
  text-transform: uppercase;
}

.rail-list {
  border-top: 1px solid var(--line);
}

.rail-list li { border-bottom: 1px solid var(--line); }

.rail-link {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 11px 10px 11px 12px;
  border-left: 2px solid transparent;
  color: var(--muted);
  font-size: 15.5px;
  font-weight: 500;
  transition: color var(--ease), background-color var(--ease),
    border-color var(--ease);
}

.rail-idx {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: rgba(140, 154, 184, 0.7);
  font-variant-numeric: tabular-nums;
  transition: color var(--ease);
}

.rail-link:hover {
  color: var(--text);
  background-color: rgba(0, 224, 200, 0.06);
  border-left-color: rgba(0, 224, 200, 0.5);
}

.rail-link:hover .rail-idx { color: var(--cyan); }

.rail-link[aria-current="page"] {
  color: var(--text);
  background-color: rgba(0, 224, 200, 0.1);
  border-left-color: var(--cyan);
}

.rail-link[aria-current="page"] .rail-idx { color: var(--cyan); }

.rail-tail {
  margin-top: auto;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.rail-subscribe { width: 100%; justify-content: center; }

.rail-note {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.rail-progress {
  position: absolute;
  top: 0;
  right: -1px;
  bottom: 0;
  width: 2px;
  background: rgba(198, 208, 226, 0.1);
  pointer-events: none;
}

.rail-progress-bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleY(0);
  transform-origin: top center;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--orange) 100%);
}

.rail-scrim { display: none; }

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 22px;
  border: 1px solid var(--line-strong);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.4;
  transition: background-color var(--ease), color var(--ease),
    border-color var(--ease);
}

.btn--pulse {
  background-color: var(--orange);
  border-color: var(--orange);
  color: #0A0E18;
}

.btn--pulse:hover {
  background-color: #FF8A4C;
  border-color: #FF8A4C;
}

.btn--cyan {
  background-color: transparent;
  border-color: rgba(0, 224, 200, 0.45);
  color: var(--cyan);
}

.btn--cyan:hover {
  background-color: rgba(0, 224, 200, 0.14);
  border-color: var(--cyan);
}

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

.btn--ghost:hover {
  background-color: rgba(198, 208, 226, 0.08);
  border-color: var(--line-strong);
}

.btn--sm { padding: 8px 14px; font-size: 13.5px; }

/* ---------- 7. 页脚 ---------- */
.site-foot {
  background-color: var(--ink-800);
  border-top: 1px solid var(--line-strong);
  padding: clamp(44px, 6vw, 80px) var(--gutter) 30px;
}

.foot-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: clamp(24px, 3vw, 44px);
  max-width: 1280px;
  margin: 0 auto;
}

.foot-brand {
  display: inline-block;
  font-size: 18px;
  font-weight: 800;
  letter-spacing: -0.01em;
  transition: color var(--ease);
}

.foot-brand:hover { color: var(--cyan); }

.foot-tag {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.foot-note {
  margin-top: 14px;
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.foot-title {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.foot-title::before {
  content: "";
  width: 8px;
  height: 8px;
  background: currentColor;
  clip-path: polygon(0 0, 100% 100%, 0 100%);
}

.foot-list li + li { margin-top: 8px; }

.foot-list a {
  font-size: 15px;
  color: #CBD4E6;
  border-bottom: 1px solid transparent;
  transition: color var(--ease), border-color var(--ease);
}

.foot-list a:hover {
  color: var(--cyan);
  border-bottom-color: rgba(0, 224, 200, 0.5);
}

.foot-list--plain li {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.foot-base {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 28px;
  max-width: 1280px;
  margin: clamp(36px, 5vw, 64px) auto 0;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  line-height: 1.8;
  color: var(--muted);
}

.foot-copy { margin-left: auto; }

/* ---------- 8. 画布与网格 ---------- */
.canvas {
  width: 100%;
  max-width: 1280px;
  margin: 0 auto;
  padding-inline: var(--gutter);
}

.section {
  position: relative;
  padding-block: clamp(48px, 7vw, 96px);
}

.section + .section { border-top: 1px solid var(--line); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: clamp(24px, 3vw, 40px);
}

.grid {
  display: grid;
  gap: clamp(18px, 2.2vw, 32px);
}

.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, 1.15fr) minmax(0, 0.85fr);
}

.rule {
  height: 1px;
  border: 0;
  background-color: var(--line);
}

.stack > * + * { margin-top: 16px; }

/* ---------- 9. 排版组件 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--cyan);
  text-transform: uppercase;
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background-color: currentColor;
}

.lede {
  max-width: 62ch;
  font-size: clamp(1.05rem, 1.35vw, 1.25rem);
  line-height: 1.75;
  color: var(--text-soft);
}

.prose {
  max-width: 70ch;
  color: var(--text-soft);
}

.prose p + p { margin-top: 1em; }

.prose a {
  color: var(--cyan);
  border-bottom: 1px solid rgba(0, 224, 200, 0.4);
}

.crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.crumbs li {
  display: flex;
  align-items: center;
  gap: 10px;
}

.crumbs li::after {
  content: "/";
  color: rgba(140, 154, 184, 0.5);
}

.crumbs li:last-child::after { display: none; }

.crumbs a { transition: color var(--ease); }
.crumbs a:hover { color: var(--cyan); }
.crumbs [aria-current="page"] { color: var(--text); }

/* ---------- 10. 面板 / 数据 / 标签 / 状态 ---------- */
.panel {
  position: relative;
  padding: clamp(18px, 2.4vw, 28px);
  background-color: var(--ink-700);
  border: 1px solid var(--line);
}

.panel::before {
  content: "";
  position: absolute;
  top: -1px;
  left: -1px;
  width: 26px;
  height: 2px;
  background-color: var(--cyan);
}

.panel--link { transition: background-color var(--ease), border-color var(--ease); }

.panel--link:hover {
  background-color: var(--ink-600);
  border-color: var(--line-strong);
}

.stat { display: block; }

.stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.6em;
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.2;
  font-variant-numeric: tabular-nums;
  color: var(--text);
}

.stat--hot .stat-num { color: var(--orange); }
.stat--cool .stat-num { color: var(--cyan); }

.stat-label {
  display: block;
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  padding: 4px 11px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
  transition: color var(--ease), border-color var(--ease),
    background-color var(--ease);
}

.tag:hover {
  color: var(--text);
  border-color: var(--line-strong);
}

.tag--on,
.tag[aria-pressed="true"] {
  color: var(--cyan);
  border-color: rgba(0, 224, 200, 0.5);
  background-color: rgba(0, 224, 200, 0.08);
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.status-dot {
  width: 7px;
  height: 7px;
  flex: 0 0 7px;
  background-color: var(--green);
  box-shadow: 0 0 0 3px rgba(43, 224, 138, 0.14);
}

.status--live .status-dot {
  background-color: var(--orange);
  box-shadow: 0 0 0 3px rgba(255, 107, 31, 0.16);
}

.status--done .status-dot {
  background-color: var(--muted);
  box-shadow: none;
}

/* ---------- 11. 图像容器（页面阶段放图） ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background-color: var(--ink-800);
  border: 1px solid var(--line);
}

.media-frame img,
.media-frame svg,
.media-frame video {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: contrast(1.08) saturate(0.85) brightness(0.86);
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(180deg, rgba(6, 10, 22, 0.1) 0%, rgba(6, 10, 22, 0.62) 100%),
    repeating-linear-gradient(90deg, rgba(0, 224, 200, 0.14) 0 1px, transparent 1px 56px),
    repeating-linear-gradient(0deg, rgba(0, 224, 200, 0.1) 0 1px, transparent 1px 56px);
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

/* ---------- 12. 横向滚动单元 ---------- */
.track-wrap { position: relative; }

.track {
  display: flex;
  gap: 14px;
  overflow-x: auto;
  padding-bottom: 14px;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
  scrollbar-color: rgba(0, 224, 200, 0.4) transparent;
}

.track::-webkit-scrollbar { height: 6px; }
.track::-webkit-scrollbar-track { background: rgba(198, 208, 226, 0.08); }

.track::-webkit-scrollbar-thumb {
  background: rgba(0, 224, 200, 0.42);
}

.track-item {
  flex: 0 0 clamp(220px, 26vw, 300px);
  scroll-snap-align: start;
}

.track-controls {
  display: flex;
  gap: 8px;
  justify-content: flex-end;
  margin-top: 12px;
}

.track-btn {
  width: 40px;
  height: 34px;
  border: 1px solid var(--line-strong);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 14px;
  line-height: 1;
  transition: color var(--ease), border-color var(--ease),
    background-color var(--ease);
}

.track-btn:hover:not(:disabled) {
  color: var(--ink-900);
  background-color: var(--cyan);
  border-color: var(--cyan);
}

.track-btn:disabled {
  color: rgba(140, 154, 184, 0.45);
  border-color: var(--line);
  cursor: not-allowed;
}

/* ---------- 13. 折叠深度内容 ---------- */
.fold { border-top: 1px solid var(--line); }
.fold:last-of-type { border-bottom: 1px solid var(--line); }

.fold summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 0;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  transition: color var(--ease);
}

.fold summary::-webkit-details-marker { display: none; }

.fold summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--cyan);
}

.fold[open] summary::after { content: "\2013"; }
.fold summary:hover { color: var(--cyan); }

.fold-body {
  padding-bottom: 20px;
  max-width: 70ch;
  color: var(--text-soft);
}

/* ---------- 14. 显现协议 ---------- */
@media (prefers-reduced-motion: no-preference) {
  [data-reveal].is-armed {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity var(--ease), transform var(--ease);
  }

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

/* ---------- 15. 平板 / 移动端：轨道收为顶栏 + 抽屉 ---------- */
@media (max-width: 1024px) {
  body { padding-left: 0; }

  .site-rail {
    position: sticky;
    top: 0;
    left: auto;
    bottom: auto;
    width: 100%;
    height: 56px;
    display: flex;
    align-items: center;
    border-right: 0;
    border-bottom: 1px solid var(--line-strong);
  }

  .rail-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    width: 100%;
    height: 100%;
    padding-inline: var(--gutter);
  }

  .rail-bar .brand-glyph {
    flex: 0 0 30px;
    width: 30px;
    height: 30px;
    font-size: 11px;
  }

  .rail-inner {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    z-index: 70;
    width: min(86vw, 340px);
    padding: 26px 20px 24px;
    background-color: var(--ink-800);
    border-right: 1px solid var(--line-strong);
    transform: translateX(-101%);
    visibility: hidden;
    transition: transform var(--ease), visibility var(--ease);
  }

  .site-rail[data-open="true"] .rail-inner {
    transform: translateX(0);
    visibility: visible;
  }

  .site-rail[data-open="true"] .rail-bar { visibility: hidden; }

  .rail-progress { display: none; }

  .rail-scrim {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 65;
    background-color: rgba(6, 10, 22, 0.74);
  }

  .site-rail[data-open="true"] .rail-scrim { display: block; }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    padding: 8px 12px;
    border: 1px solid var(--line-strong);
    font-family: var(--font-mono);
    font-size: 12px;
    letter-spacing: 0.12em;
    color: var(--text);
    transition: color var(--ease), border-color var(--ease);
  }

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

  .nav-toggle-bars {
    position: relative;
    display: block;
    width: 14px;
    height: 8px;
  }

  .nav-toggle-bars::before,
  .nav-toggle-bars::after {
    content: "";
    position: absolute;
    left: 0;
    width: 100%;
    height: 1px;
    background-color: currentColor;
    transition: transform var(--ease), top var(--ease);
  }

  .nav-toggle-bars::before { top: 0; }
  .nav-toggle-bars::after { top: 6px; }

  .nav-toggle[aria-expanded="true"] {
    color: var(--cyan);
    border-color: var(--cyan);
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle-bars::before {
    top: 3px;
    transform: rotate(45deg);
  }

  .nav-toggle[aria-expanded="true"] .nav-toggle-bars::after {
    top: 3px;
    transform: rotate(-45deg);
  }

  .foot-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }

  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--split { grid-template-columns: minmax(0, 1fr); }
}

@media (min-width: 1025px) {
  .nav-toggle { display: none; }
}

@media (max-width: 720px) {
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: minmax(0, 1fr); }

  .foot-grid { grid-template-columns: minmax(0, 1fr); }
  .foot-copy { margin-left: 0; }
  .foot-base { flex-direction: column; gap: 6px; }

  .track-item { flex-basis: 78vw; }
  .section { padding-block: clamp(36px, 9vw, 56px); }
}

/* ---------- 16. 减少动效 ---------- */
@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;
  }

  .track { scroll-behavior: auto; scroll-snap-type: none; }
  .skip-link { transform: none; }
}