/* ============================================================
   艾乐棋牌 · 共享站壳样式 /assets/site.css
   棋盘格底纹 + 墨绿深底 + 鎏金锚点 + 侧边轨道导航
   ============================================================ */

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

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

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

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

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

button, input, select, textarea { font: inherit; color: inherit; }

button { background: none; border: 0; }

table { border-collapse: collapse; }

/* ---------- 2. 变量 ---------- */
:root {
  --ink: #0B1F1A;
  --ink-2: #102E26;
  --line: #1B4A3C;
  --gold: #C9A227;
  --gold-soft: #F2D786;
  --cyan: #3FE0C8;
  --violet: #8B5CF6;
  --alert: #FF5C73;
  --ivory: #F5F3EC;
  --muted: #8FA39C;
  --ink-text: #10231E;
  --ink-text-soft: #4A635B;

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

  --rail-w: 104px;
  --header-h: 68px;
  --radius-lg: 28px;
  --radius-md: 18px;
  --radius-pill: 999px;
  --ease-out: cubic-bezier(.22, 1, .36, 1);
}

@media (max-width: 900px) {
  :root { --rail-w: 0px; --header-h: 60px; --radius-lg: 22px; }
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  padding-top: var(--header-h);
  padding-left: var(--rail-w);
  background-color: var(--ink);
  background-image:
    linear-gradient(to right, rgba(27, 74, 60, .26) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(27, 74, 60, .26) 1px, transparent 1px);
  background-size: 96px 96px;
  color: var(--ivory);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  font-weight: 400;
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
}

@media (min-width: 901px) {
  body { background-attachment: fixed; }
}

a { color: inherit; }

:focus-visible {
  outline: 2px solid var(--gold-soft);
  outline-offset: 3px;
  border-radius: 6px;
}

.skip-link {
  position: fixed;
  left: 14px;
  top: -90px;
  z-index: 999;
  padding: 12px 22px;
  border-radius: var(--radius-pill);
  background: var(--gold);
  color: var(--ink-text);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  transition: top .2s var(--ease-out);
}

.skip-link:focus { top: 14px; }

/* ---------- 4. 顶部进度条 ---------- */
.scroll-meter {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: 3px;
  z-index: 96;
  background: rgba(27, 74, 60, .5);
  pointer-events: none;
}

.scroll-meter-bar {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, var(--gold), var(--cyan));
  transition: width .12s linear;
}

/* ---------- 5. 侧边轨道导航 ---------- */
.site-nav {
  position: fixed;
  top: 0; bottom: 0; left: 0;
  width: var(--rail-w);
  z-index: 75;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: calc(var(--header-h) + 26px) 0 28px;
  background: linear-gradient(180deg, #0D251F 0%, #0B1F1A 62%, #081713 100%);
  border-right: 1px solid var(--line);
  overflow-y: auto;
}

.nav-caption {
  position: absolute;
  top: calc(var(--header-h) + 16px);
  left: 0; right: 0;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .26em;
  color: var(--muted);
  opacity: .75;
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.nav-link {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  padding: 13px 4px;
  border-left: 2px solid transparent;
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
  line-height: 1.2;
  letter-spacing: .02em;
  transition: color .2s ease, background .2s ease, border-color .2s ease;
}

.nav-idx {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .16em;
  opacity: .7;
}

.nav-label { white-space: nowrap; }

.nav-link:hover {
  color: var(--ivory);
  background: rgba(201, 162, 39, .08);
}

.nav-link[aria-current="page"] {
  color: var(--gold-soft);
  border-left-color: var(--gold);
  background: linear-gradient(90deg, rgba(201, 162, 39, .18), rgba(201, 162, 39, 0));
}

.nav-link[aria-current="page"] .nav-idx { color: var(--gold); opacity: 1; }

.nav-scrim,
.collect-scrim {
  position: fixed;
  inset: 0;
  z-index: 74;
  background: rgba(4, 12, 10, .68);
  opacity: 0;
  pointer-events: none;
  transition: opacity .26s ease;
}

.collect-scrim { z-index: 91; }

.site-header[data-nav-open="true"] .nav-scrim { opacity: 1; pointer-events: auto; }
.site-header[data-collect-open="true"] .collect-scrim { opacity: 1; pointer-events: auto; }

/* ---------- 6. 顶部玻璃条 ---------- */
.header-top {
  position: fixed;
  top: 0;
  left: var(--rail-w);
  right: 0;
  height: var(--header-h);
  z-index: 78;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  padding: 0 clamp(16px, 3vw, 40px);
  background: rgba(11, 31, 26, .86);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
  min-width: 0;
}

.brand-glyph {
  flex: none;
  width: 42px;
  height: 42px;
  display: grid;
  place-items: center;
  border-radius: 14px;
  background: linear-gradient(145deg, var(--gold-soft), var(--gold));
  color: var(--ink-text);
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -.02em;
}

.brand-copy {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
  min-width: 0;
}

.brand-name {
  font-size: 17px;
  font-weight: 800;
  letter-spacing: -.02em;
  color: var(--ivory);
}

.brand-tag {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .12em;
  color: var(--muted);
}

.brand-version {
  flex: none;
  padding: 5px 12px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(201, 162, 39, .55);
  background: rgba(201, 162, 39, .12);
  color: var(--gold-soft);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
}

.header-tools {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-left: auto;
}

.collect-toggle,
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  min-height: 40px;
  padding: 0 16px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
  background: rgba(16, 46, 38, .7);
  color: var(--ivory);
  font-size: 13px;
  letter-spacing: .04em;
  cursor: pointer;
  transition: border-color .2s ease, color .2s ease, background .2s ease, transform .18s ease;
}

.collect-toggle:hover,
.nav-toggle:hover {
  border-color: var(--gold);
  color: var(--gold-soft);
  transform: translateY(-1px);
}

.collect-icon {
  width: 16px;
  height: 16px;
  background-image: radial-gradient(currentColor 1.6px, transparent 1.7px);
  background-size: 8px 8px;
  background-position: 1px 1px;
  color: var(--gold);
}

.collect-num {
  min-width: 22px;
  padding: 1px 6px;
  border-radius: var(--radius-pill);
  background: rgba(201, 162, 39, .2);
  color: var(--gold-soft);
  font-family: var(--font-mono);
  font-size: 11px;
  text-align: center;
}

.nav-toggle-icon {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 3px;
  width: 16px;
  height: 14px;
}

.nav-toggle-icon i {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: var(--cyan);
}

/* ---------- 7. 小屏收藏抽屉 ---------- */
.collect-drawer {
  position: fixed;
  top: 0; right: 0; bottom: 0;
  width: min(348px, 90vw);
  z-index: 92;
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 24px clamp(18px, 4vw, 26px) 30px;
  background: linear-gradient(180deg, #102E26, #0B1F1A);
  border-left: 1px solid var(--line);
  box-shadow: -30px 0 70px rgba(0, 0, 0, .45);
  transform: translateX(104%);
  transition: transform .28s var(--ease-out);
  overflow-y: auto;
}

.collect-drawer[data-open="true"] { transform: translateX(0); }

.drawer-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.drawer-title {
  font-size: 17px;
  font-weight: 800;
  letter-spacing: -.02em;
}

.drawer-close {
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
  letter-spacing: .1em;
  cursor: pointer;
  transition: color .2s ease, border-color .2s ease;
}

.drawer-close:hover { color: var(--gold-soft); border-color: var(--gold); }

.drawer-note {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--muted);
}

.drawer-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.drawer-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 13px 16px;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  background: rgba(11, 31, 26, .7);
  transition: transform .22s var(--ease-out), border-color .22s ease;
}

.drawer-item:hover { transform: translateY(-4px); border-color: rgba(201, 162, 39, .6); }

.drawer-item a {
  font-size: 14.5px;
  text-decoration: none;
  color: var(--ivory);
}

.drawer-item a:hover { color: var(--gold-soft); }

.drawer-foot {
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--muted);
}

/* ---------- 8. 返回顶部 ---------- */
.to-top {
  position: fixed;
  right: clamp(14px, 2vw, 28px);
  bottom: clamp(16px, 3vh, 32px);
  z-index: 90;
  width: 54px;
  height: 54px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  border: 1px solid var(--line);
  background: rgba(16, 46, 38, .92);
  color: var(--gold-soft);
  font-size: 18px;
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(14px);
  transition: opacity .25s ease, transform .25s var(--ease-out), visibility .25s, border-color .2s ease;
}

.to-top[data-visible="true"] { opacity: 1; visibility: visible; transform: translateY(0); }

.to-top:hover { border-color: var(--gold); background: rgba(201, 162, 39, .2); }

/* ---------- 9. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 7vw, 112px);
  padding: clamp(40px, 5vw, 74px) 0 22px;
  background: linear-gradient(180deg, rgba(11, 31, 26, .4), #071511 60%);
  border-top: 1px solid var(--line);
}

.footer-inner {
  width: 100%;
  max-width: 1240px;
  margin-inline: auto;
  padding-inline: clamp(18px, 3.2vw, 48px);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1.15fr 1.15fr;
  gap: clamp(24px, 3vw, 48px);
}

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

.footer-title {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .18em;
  color: var(--gold);
}

.footer-subtitle {
  margin: 22px 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .16em;
  color: var(--muted);
}

.footer-list {
  display: flex;
  flex-direction: column;
  gap: 9px;
}

.footer-list a {
  color: var(--muted);
  font-size: 14.5px;
  text-decoration: none;
  transition: color .18s ease;
}

.footer-list a:hover { color: var(--gold-soft); }

.footer-list--plain li {
  color: var(--muted);
  font-size: 13.5px;
  line-height: 1.65;
}

.brand--footer { margin-bottom: 16px; }

.footer-lede {
  max-width: 32em;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
}

.footer-chip {
  display: inline-block;
  margin-top: 16px;
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(201, 162, 39, .45);
  background: rgba(201, 162, 39, .1);
  color: var(--gold-soft);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
}

.footer-bottom {
  margin-top: clamp(28px, 4vw, 54px);
  padding-top: 18px;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  justify-content: space-between;
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
}

/* ---------- 10. 页面骨架 ---------- */
.page-main { display: block; }

.container {
  width: 100%;
  max-width: 1240px;
  margin-inline: auto;
  padding-inline: clamp(18px, 3.2vw, 48px);
}

.chapter {
  position: relative;
  padding-block: clamp(56px, 8vw, 132px);
}

.chapter--light {
  background: var(--ivory);
  color: var(--ink-text);
}

.chapter--light .eyebrow,
.chapter--light .lede,
.chapter--light .footer-list--plain li { color: var(--ink-text-soft); }

.chapter--light .section-title { color: #0B1F1A; }

.chapter-band {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: clamp(22px, 3vw, 40px);
}

.chapter-band::after {
  content: "";
  flex: 1;
  height: 8px;
  border-radius: var(--radius-pill);
  background: linear-gradient(90deg, var(--gold), var(--cyan) 82%, var(--violet));
}

.chapter-num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--gold);
}

.grid { display: grid; gap: clamp(16px, 2vw, 28px); }

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

.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-12 { grid-column: span 12; }

/* ---------- 11. 文字层级 ---------- */
.eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted);
}

.display-title {
  font-size: clamp(44px, 8.4vw, 132px);
  font-weight: 250;
  line-height: .96;
  letter-spacing: -.01em;
  color: var(--ivory);
}

.section-title {
  margin-bottom: 12px;
  font-size: clamp(20px, 2.3vw, 32px);
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.24;
}

.lede {
  max-width: 34em;
  color: var(--muted);
  font-size: clamp(15px, 1.15vw, 17px);
  line-height: 1.8;
}

.prose {
  max-width: 34em;
  font-size: 16px;
  line-height: 1.8;
}

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

.breadcrumb {
  margin-bottom: clamp(18px, 2.6vw, 34px);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
}

.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
}

.breadcrumb a { text-decoration: none; }
.breadcrumb a:hover { color: var(--gold-soft); }
.breadcrumb li + li::before { content: "/"; margin-right: 8px; opacity: .5; }

/* ---------- 12. 按钮与标签 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 0 24px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .01em;
  text-decoration: none;
  cursor: pointer;
  transition: transform .18s var(--ease-out), background .2s ease, color .2s ease, border-color .2s ease;
}

.btn--gold {
  background: var(--gold);
  color: var(--ink-text);
}

.btn--gold:hover { background: var(--gold-soft); transform: translateY(-2px); }

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

.btn--ghost:hover { border-color: var(--gold); color: var(--gold-soft); transform: translateY(-2px); }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
  background: rgba(27, 74, 60, .28);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  white-space: nowrap;
  transition: color .12s linear, border-color .12s linear, background .12s linear;
}

.chip--ok {
  color: var(--cyan);
  border-color: rgba(63, 224, 200, .5);
  background: rgba(63, 224, 200, .1);
}

.chip--wip {
  color: var(--violet);
  border-color: rgba(139, 92, 246, .5);
  background: rgba(139, 92, 246, .12);
}

.chip--alert {
  color: var(--alert);
  border-color: rgba(255, 92, 115, .5);
  background: rgba(255, 92, 115, .1);
}

/* ---------- 13. 卡片 / 研究板 / 数据模块 ---------- */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 30px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: rgba(16, 46, 38, .82);
  transition: transform .24s var(--ease-out), border-color .24s ease;
}

.card:hover { transform: translateY(-4px); border-color: rgba(201, 162, 39, .55); }

.study-board {
  display: grid;
  gap: clamp(16px, 2vw, 26px);
  padding: clamp(20px, 2.6vw, 34px);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: linear-gradient(180deg, rgba(16, 46, 38, .92), rgba(11, 31, 26, .92));
}

.board-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.board-title {
  font-size: clamp(18px, 1.8vw, 24px);
  font-weight: 800;
  letter-spacing: -.02em;
}

.board-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: clamp(14px, 2vw, 24px);
}

.board-foot {
  padding-top: 14px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .12em;
}

.kpi {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.kpi-num {
  font-family: var(--font-mono);
  font-size: clamp(30px, 4vw, 52px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--gold-soft);
}

.kpi-label {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--muted);
}

/* ---------- 14. 图片容器（页面阶段放入 img / svg） ---------- */
.media-frame {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: linear-gradient(140deg, #0D2721, #102E26 55%, #0B1F1A);
}

.media-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(45deg, rgba(201, 162, 39, .12) 25%, transparent 25%, transparent 75%, rgba(201, 162, 39, .12) 75%),
    linear-gradient(45deg, rgba(201, 162, 39, .12) 25%, transparent 25%, transparent 75%, rgba(201, 162, 39, .12) 75%);
  background-size: 56px 56px;
  background-position: 0 0, 28px 28px;
}

.media-frame > img,
.media-frame > svg,
.media-frame > picture {
  position: relative;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media-frame--wide { aspect-ratio: 16 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }

/* ---------- 15. 表格 ---------- */
.data-table {
  width: 100%;
  font-size: 14.5px;
}

.data-table th,
.data-table td {
  padding: 12px 14px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--line);
}

.data-table thead th {
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 500;
  letter-spacing: .14em;
  color: var(--muted);
  text-transform: uppercase;
}

.data-table tbody tr:nth-child(even) { background: rgba(16, 46, 38, .55); }

.data-table tbody tr:hover { background: rgba(201, 162, 39, .08); }

.chapter--light .data-table th,
.chapter--light .data-table td { border-bottom-color: rgba(11, 31, 26, .14); }

.chapter--light .data-table thead th { color: var(--ink-text-soft); }

.chapter--light .data-table tbody tr:nth-child(even) { background: rgba(11, 31, 26, .045); }

.chapter--light .data-table tbody tr:hover { background: rgba(201, 162, 39, .14); }

/* ---------- 16. 滚动显现 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .6s ease, transform .6s var(--ease-out);
}

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

/* ---------- 17. 响应式 ---------- */
@media (max-width: 1100px) {
  .footer-grid { grid-template-columns: 1.3fr 1fr 1fr; }
  .footer-col:last-child { grid-column: span 3; }
}

@media (max-width: 900px) {
  body { padding-left: 0; }

  .site-nav {
    width: min(304px, 86vw);
    justify-content: flex-start;
    padding: calc(var(--header-h) + 30px) 0 32px;
    background: linear-gradient(180deg, #102E26, #0B1F1A);
    box-shadow: 26px 0 66px rgba(0, 0, 0, .5);
    transform: translateX(-104%);
    transition: transform .3s var(--ease-out);
  }

  .site-nav[data-open="true"] { transform: translateX(0); }

  .nav-caption {
    position: static;
    padding: 0 24px 14px;
    text-align: left;
  }

  .nav-link {
    flex-direction: row;
    justify-content: flex-start;
    align-items: center;
    gap: 14px;
    padding: 15px 24px;
    border-left: 3px solid transparent;
    font-size: 15px;
    text-align: left;
  }

  .nav-idx { font-size: 11px; }

  .grid-12 { grid-template-columns: 1fr; }

  .span-3, .span-4, .span-5, .span-6, .span-7, .span-8, .span-12 { grid-column: auto; }

  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-col:last-child { grid-column: span 2; }
}

@media (max-width: 640px) {
  .collect-text { display: none; }

  .collect-toggle, .nav-toggle { padding: 0 13px; }

  .brand-version { display: none; }

  .brand-tag { display: none; }

  .footer-grid { grid-template-columns: 1fr; }
  .footer-col:last-child { grid-column: auto; }

  .footer-bottom { flex-direction: column; }

  .display-title { font-size: clamp(38px, 13vw, 62px); }
}

/* ---------- 18. 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;
    scroll-behavior: auto !important;
  }

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

  .scroll-meter-bar { transition: none; }
}