/* =========================================================
   百博看台 · /assets/site.css
   共享：Reset / 变量 / 排版 / 头部 / 页脚 / 通用组件
   ========================================================= */

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

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

body { margin: 0; }

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

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

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

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

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

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

/* ---------- 2. 设计变量 ---------- */
:root {
  --ink: #07120F;
  --pine: #0B1B16;
  --card: #123328;
  --line: #1A4A38;
  --mint: #45F0B2;
  --mint-soft: #7DF7CB;
  --amber: #F6B84A;
  --amber-soft: #FBDCA3;
  --paper: #E9F3EE;
  --muted: #93AFA3;
  --shadow-ink: #020806;
  --coral: #FF7A6E;

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

  --edge: 2px solid var(--line);
  --slab: 7px 7px 0 var(--shadow-ink);
  --slab-sm: 4px 4px 0 var(--shadow-ink);
  --maxw: 1280px;
  --gutter: clamp(1rem, 4vw, 2.5rem);
}

/* ---------- 3. 基准排版 ---------- */
body {
  background-color: var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-head);
  font-weight: 900;
  line-height: 1.15;
  letter-spacing: -0.025em;
  color: var(--paper);
}

::selection {
  background: var(--mint);
  color: var(--ink);
}

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

#main-content:focus { outline: none; }

/* ---------- 4. 容器与节奏 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(2.5rem, 6vw, 4.5rem); }
.section--tight { padding-block: clamp(1.5rem, 3.5vw, 2.5rem); }

.divider {
  height: 1px;
  background: var(--line);
  border: 0;
  margin-block: clamp(1.5rem, 4vw, 2.5rem);
}

.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;
}

/* ---------- 5. 跳过链接 ---------- */
.skip-link {
  position: absolute;
  left: 1rem;
  top: -120px;
  z-index: 999;
  padding: 0.7rem 1.15rem;
  background: var(--mint);
  color: var(--ink);
  border: 2px solid var(--ink);
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  transition: top 0.16s ease;
}

.skip-link:focus {
  top: 0.75rem;
  outline: 3px solid var(--mint-soft);
  outline-offset: 2px;
}

/* ---------- 6. 头部：三段式命令栏 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 200;
  background: var(--ink);
  border-bottom: 2px solid var(--line);
  isolate: isolate;
}

/* 6.1 索引刻度轨 */
.header-rail {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.34rem var(--gutter);
  background: var(--pine);
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.66rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
}

.rail-dot {
  flex: 0 0 auto;
  width: 0.5rem;
  height: 0.5rem;
  background: var(--mint);
  border-radius: 50%;
  box-shadow: 0 0 0 3px rgba(69, 240, 178, 0.16);
}

.rail-text { flex: 0 0 auto; }

.rail-text--mint {
  color: var(--mint);
  font-weight: 700;
}

.rail-sep {
  flex: 0 0 auto;
  width: 1px;
  height: 0.72rem;
  background: var(--line);
}

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

.rail-stamp {
  flex: 0 0 auto;
  color: var(--amber);
  font-weight: 700;
}

/* 6.2 主命令栏 */
.header-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
  padding-block: 0.85rem;
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 0.18rem;
  flex: 0 0 auto;
  line-height: 1;
}

.brand-mark {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.3rem, 2.2vw, 1.6rem);
  letter-spacing: -0.045em;
  color: var(--paper);
  display: inline-flex;
  align-items: baseline;
}

.brand-mark::after {
  content: "";
  display: inline-block;
  width: 0.4rem;
  height: 0.4rem;
  margin-left: 0.42rem;
  background: var(--mint);
  transform: translateY(-0.05em);
}

.brand-desc {
  font-family: var(--font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

/* 6.3 移动端开关 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 0.55rem;
  flex: 0 0 auto;
  padding: 0.45rem 0.72rem;
  border: 2px solid var(--line);
  background: var(--card);
  color: var(--paper);
  box-shadow: var(--slab-sm);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  transition: color 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}

.nav-toggle:hover,
.nav-toggle:focus-visible {
  color: var(--mint);
  border-color: var(--mint);
}

.nav-toggle.is-open {
  background: var(--pine);
  color: var(--mint);
  border-color: var(--mint);
}

.nav-toggle-icon {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 3px;
  width: 16px;
}

.nav-toggle-icon i {
  display: block;
  height: 2px;
  background: currentColor;
}

.nav-toggle-icon i:nth-child(1) { width: 16px; }
.nav-toggle-icon i:nth-child(2) { width: 11px; }
.nav-toggle-icon i:nth-child(3) { width: 16px; }

.nav-toggle-text { line-height: 1; }

/* 6.4 导航面板 */
.header-panel {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 1.25rem;
  flex: 1 1 auto;
  min-width: 0;
}

.site-nav { min-width: 0; }

.nav-list {
  display: flex;
  align-items: center;
  gap: 0.1rem;
  flex-wrap: nowrap;
}

.nav-item { flex: 0 0 auto; }

.nav-link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.4rem;
  padding: 0.5rem 0.6rem;
  border-bottom: 2px solid transparent;
  font-family: var(--font-body);
  font-size: 0.92rem;
  font-weight: 600;
  color: var(--paper);
  transition: color 0.18s ease, border-color 0.18s ease;
}

.nav-num {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--muted);
  transition: color 0.18s ease;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--mint);
  border-bottom-color: var(--mint);
}

.nav-link:hover .nav-num,
.nav-link:focus-visible .nav-num { color: var(--mint); }

.nav-link[aria-current="page"] {
  color: var(--mint);
  border-bottom-color: var(--mint);
}

.nav-link[aria-current="page"] .nav-num { color: var(--mint); }

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.7rem 1.15rem;
  border: 2px solid var(--line);
  background: var(--card);
  color: var(--paper);
  box-shadow: var(--slab-sm);
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  line-height: 1.2;
  text-align: center;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 var(--shadow-ink);
  border-color: var(--mint);
}

.btn:active {
  transform: translate(1px, 1px);
  box-shadow: 2px 2px 0 var(--shadow-ink);
}

.btn--primary {
  background: var(--mint);
  border-color: var(--mint);
  color: var(--ink);
}

.btn--primary:hover {
  background: var(--mint-soft);
  border-color: var(--mint-soft);
  color: var(--ink);
}

.btn--amber {
  background: var(--amber);
  border-color: var(--amber);
  color: #231503;
}

.btn--amber:hover {
  background: var(--amber-soft);
  border-color: var(--amber-soft);
  color: #231503;
}

.btn--ghost {
  background: transparent;
  color: var(--paper);
}

.btn--ghost:hover {
  background: var(--pine);
  color: var(--mint);
}

.header-cta {
  flex: 0 0 auto;
  padding: 0.62rem 1rem;
  font-size: 0.74rem;
}

/* ---------- 8. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(3rem, 8vw, 6rem);
  background: var(--ink);
  border-top: 2px solid var(--line);
  color: var(--paper);
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 2fr);
  gap: clamp(1.75rem, 4vw, 3.25rem);
  padding-block: clamp(2rem, 5vw, 3.5rem) clamp(1.5rem, 4vw, 2.5rem);
}

.footer-brand { min-width: 0; }

.footer-mark {
  display: inline-block;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.6rem, 3vw, 2.05rem);
  letter-spacing: -0.04em;
  line-height: 1.1;
  padding-bottom: 0.55rem;
  border-bottom: 2px solid var(--mint);
}

.footer-statement {
  margin-top: 0.85rem;
  max-width: 26ch;
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--muted);
}

.footer-contact {
  display: grid;
  gap: 0.4rem;
  margin-top: 1.35rem;
}

.footer-contact-item {
  display: flex;
  align-items: baseline;
  gap: 0.7rem;
  font-size: 0.84rem;
  line-height: 1.6;
}

.footer-contact-key {
  flex: 0 0 2.9rem;
  font-family: var(--font-mono);
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mint);
}

.footer-contact-val {
  color: var(--muted);
  word-break: break-word;
}

.footer-nav {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: clamp(1rem, 2.5vw, 2rem);
  min-width: 0;
}

.footer-col { min-width: 0; }

.footer-col-title {
  margin-bottom: 0.85rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--amber);
  line-height: 1.4;
}

.footer-list {
  display: grid;
  gap: 0.5rem;
}

.footer-link {
  position: relative;
  display: inline-block;
  padding-left: 0.85rem;
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--muted);
  transition: color 0.16s ease, padding-left 0.16s ease;
}

.footer-link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 0.35rem;
  height: 1px;
  background: var(--line);
  transition: background 0.16s ease, width 0.16s ease;
}

.footer-link:hover,
.footer-link:focus-visible {
  color: var(--mint);
  padding-left: 1rem;
}

.footer-link:hover::before,
.footer-link:focus-visible::before {
  width: 0.55rem;
  background: var(--mint);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 1.75rem;
  padding-block: 1.15rem 1.75rem;
  border-top: 1px solid var(--line);
}

.footer-legal {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.footer-note {
  max-width: 62ch;
  font-family: var(--font-body);
  font-size: 0.76rem;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 9. 标题系统 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--mint);
}

.eyebrow::before {
  content: "";
  width: 1.4rem;
  height: 2px;
  background: var(--mint);
}

.section-index {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--mint);
}

.section-title {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.75rem, 3.6vw, 2.5rem);
  line-height: 1.15;
  letter-spacing: -0.03em;
  color: var(--paper);
  margin-top: 0.5rem;
}

.lede {
  margin-top: 0.9rem;
  max-width: 44ch;
  font-size: clamp(1rem, 1.4vw, 1.1rem);
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 10. 面包屑 ---------- */
.crumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.crumbs a {
  color: var(--muted);
  border-bottom: 1px solid transparent;
  transition: color 0.16s ease, border-color 0.16s ease;
}

.crumbs a:hover,
.crumbs a:focus-visible {
  color: var(--mint);
  border-bottom-color: var(--mint);
}

.crumbs__sep {
  color: var(--line);
  font-size: 0.62rem;
}

/* ---------- 11. 正文容器 ---------- */
.prose {
  max-width: 44rem;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--paper);
}

.prose p { margin-bottom: 1.1rem; }
.prose p:last-child { margin-bottom: 0; }

.prose ul,
.prose ol {
  margin: 0 0 1.1rem;
  padding-left: 1.15rem;
  list-style: none;
}

.prose li {
  position: relative;
  margin-bottom: 0.5rem;
  padding-left: 0.85rem;
  color: var(--muted);
}

.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 0.4rem;
  height: 2px;
  background: var(--mint);
}

.prose h3 {
  margin: 1.75rem 0 0.75rem;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
}

.prose a {
  color: var(--mint);
  border-bottom: 1px solid var(--line);
  transition: border-color 0.16s ease;
}

.prose a:hover { border-bottom-color: var(--mint); }

.prose strong { color: var(--paper); font-weight: 700; }

/* ---------- 12. 网格 ---------- */
.grid {
  display: grid;
  gap: clamp(1rem, 2.5vw, 1.75rem);
}

.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }

.grid--12 > * { grid-column: span 12; }

@media (min-width: 901px) {
  .col-4 { grid-column: span 4; }
  .col-5 { grid-column: span 5; }
  .col-6 { grid-column: span 6; }
  .col-7 { grid-column: span 7; }
  .col-8 { grid-column: span 8; }
}

/* ---------- 13. 档案卡 ---------- */
.card {
  position: relative;
  padding: clamp(1.1rem, 2.4vw, 1.5rem);
  background: var(--card);
  border: var(--edge);
  box-shadow: var(--slab);
}

.card--flat { box-shadow: none; }

/* ---------- 14. 数据条带 ---------- */
.data-strip {
  display: flex;
  flex-wrap: wrap;
  gap: 1px;
  background: var(--line);
  border: var(--edge);
  box-shadow: var(--slab);
}

.data-strip__cell {
  flex: 1 1 11rem;
  display: grid;
  gap: 0.15rem;
  padding: 0.95rem 1.1rem;
  background: var(--pine);
}

.data-strip__key {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.data-strip__val {
  font-family: var(--font-mono);
  font-size: clamp(1.35rem, 2.4vw, 1.75rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--mint);
}

.data-strip__val--amber { color: var(--amber); }

/* ---------- 15. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.18rem 0.55rem;
  border: 1px solid var(--line);
  background: var(--pine);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.66rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  line-height: 1.6;
  white-space: nowrap;
}

.tag--mint {
  background: var(--mint);
  border-color: var(--mint);
  color: var(--ink);
}

.tag--amber {
  background: var(--amber);
  border-color: var(--amber);
  color: #231503;
}

/* ---------- 16. 图片容器 ---------- */
.media-frame {
  position: relative;
  margin: 0;
  border: var(--edge);
  background: var(--card);
  box-shadow: var(--slab);
  overflow: hidden;
}

.media-frame img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: var(--pine);
  filter: saturate(0.75) contrast(1.05);
}

.media-frame--tall img { aspect-ratio: 4 / 5; }
.media-frame--square img { aspect-ratio: 1 / 1; }

.media-frame__placeholder {
  display: grid;
  place-items: center;
  width: 100%;
  aspect-ratio: 16 / 9;
  padding: 1rem;
  background:
    repeating-linear-gradient(
      135deg,
      var(--pine) 0 10px,
      var(--ink) 10px 20px
    );
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  text-align: center;
}

.media-frame__caption {
  position: relative;
  padding: 0.62rem 0.85rem;
  border-top: var(--edge);
  background: var(--pine);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  line-height: 1.6;
}

/* ---------- 17. 滚动进度与返回顶部（JS 注入） ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 300;
  background: var(--mint);
  transform: scaleX(0);
  transform-origin: 0 50%;
  pointer-events: none;
  will-change: transform;
}

.to-top {
  position: fixed;
  right: clamp(0.75rem, 2vw, 1.5rem);
  bottom: clamp(0.75rem, 2vw, 1.5rem);
  z-index: 250;
  display: grid;
  place-items: center;
  width: 2.85rem;
  height: 2.85rem;
  border: var(--edge);
  background: var(--card);
  color: var(--mint);
  box-shadow: var(--slab-sm);
  font-family: var(--font-mono);
  font-size: 1rem;
  font-weight: 700;
  line-height: 1;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.2s ease, transform 0.2s ease, visibility 0.2s ease, border-color 0.16s ease, background 0.16s ease;
}

.to-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.to-top:hover,
.to-top:focus-visible {
  border-color: var(--mint);
  background: var(--pine);
}

/* ---------- 18. 进入视口显现 ---------- */
body.reveal-ready [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.24s ease, transform 0.24s ease;
}

body.reveal-ready [data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 19. 响应式：导航折叠（断点 1080px，与 SITE_JS 保持一致） ---------- */
@media (max-width: 1080px) {
  .nav-toggle { display: inline-flex; }

  .header-bar {
    flex-wrap: nowrap;
    gap: 0.9rem;
  }

  .brand { flex: 1 1 auto; min-width: 0; }

  .header-panel {
    display: none;
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0.5rem;
    padding: 1rem var(--gutter) 1.35rem;
    background: var(--pine);
    border-top: 2px solid var(--line);
    border-bottom: 2px solid var(--line);
    max-height: calc(100vh - 6rem);
    overflow-y: auto;
    box-shadow: 0 10px 0 rgba(2, 8, 6, 0.55);
  }

  .header-panel[data-open="true"] { display: flex; }

  .site-nav { width: 100%; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    width: 100%;
  }

  .nav-item { width: 100%; }

  .nav-link {
    width: 100%;
    justify-content: flex-start;
    padding: 0.8rem 0.35rem;
    border-bottom: 1px solid var(--line);
    font-size: 1rem;
  }

  .nav-link[aria-current="page"] {
    background: rgba(69, 240, 178, 0.07);
    border-bottom-color: var(--mint);
  }

  .header-cta {
    width: 100%;
    margin-top: 0.6rem;
    padding: 0.8rem 1rem;
    font-size: 0.78rem;
  }
}

/* ---------- 20. 响应式：页脚与常规尺寸 ---------- */
@media (max-width: 960px) {
  .footer-top {
    grid-template-columns: minmax(0, 1fr);
  }

  .footer-statement { max-width: 40ch; }

  .footer-nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.5rem 1.25rem;
  }
}

@media (max-width: 600px) {
  body { font-size: 15.5px; }

  .header-rail {
    font-size: 0.6rem;
    letter-spacing: 0.1em;
    gap: 0.5rem;
  }

  .rail-text:first-of-type { display: none; }

  .footer-nav { grid-template-columns: minmax(0, 1fr); }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

  .to-top {
    width: 2.6rem;
    height: 2.6rem;
  }
}

/* ---------- 21. 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;
    scroll-behavior: auto !important;
  }

  body.reveal-ready [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .btn:hover,
  .btn:active {
    transform: none;
  }
}