/* ============================================================
   冠军白菜网 · 共享样式表 /assets/site.css
   档案室 × 校订台视觉体系
   ============================================================ */

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

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

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

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

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

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

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

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

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

/* ---------- 2. 变量 ---------- */
:root {
  --ink: #14161A;
  --ink-2: #2A2E34;
  --paper: #F2F4F3;
  --sheet: #FFFFFF;
  --gold: #C39B27;
  --gold-lt: #F0D48A;
  --teal: #2E7D6B;
  --teal-dk: #1F5F51;
  --teal-lt: #C4E3D8;
  --gray: #7C858E;
  --amber: #A9660A;

  --hair: rgba(20, 22, 26, 0.12);
  --hair-2: rgba(20, 22, 26, 0.06);
  --hair-dark: rgba(242, 244, 243, 0.15);
  --glass: rgba(242, 244, 243, 0.78);
  --glass-dark: rgba(20, 22, 26, 0.84);

  --font-head: 'Noto Sans SC', 'Source Han Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Noto Serif SC', 'Source Han Serif SC', 'Songti SC', serif;
  --font-mono: 'IBM Plex Mono', 'JetBrains Mono', 'Roboto Mono', monospace;
  --font-ui: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;

  --shell: 1240px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --dur: 0.2s;
}

/* ---------- 3. 中文排版基线 ---------- */
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.9;
  letter-spacing: 0.005em;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5 {
  font-family: var(--font-head);
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.28;
}

p { margin-bottom: 1.2em; }
p:last-child { margin-bottom: 0; }

strong, b { font-weight: 700; }

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

.site-header :focus-visible,
.site-footer :focus-visible {
  outline-color: var(--gold-lt);
}

/* ---------- 4. 工具与容器 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding-left: 24px;
  padding-right: 24px;
}

.section { padding: 72px 0; }
.section--tight { padding: 40px 0; }

.band-dark {
  background: var(--ink);
  color: var(--paper);
}

.band-dark .title-xl,
.band-dark .title-lg,
.band-dark .title-md,
.band-dark .title-sm { color: #fff; }

.mono {
  font-family: var(--font-mono);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.01em;
}

.grid { display: grid; gap: 28px; }
.g-5-7 { grid-template-columns: 5fr 7fr; }
.g-4-8 { grid-template-columns: 4fr 8fr; }
.g-3-6-3 { grid-template-columns: 3fr 6fr 3fr; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-ui);
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: 0.2em;
  color: var(--amber);
  text-transform: uppercase;
  margin-bottom: 14px;
}

.eyebrow::before {
  content: "";
  width: 24px;
  height: 2px;
  background: var(--gold);
  flex: none;
}

.band-dark .eyebrow { color: var(--gold-lt); }

.lede {
  font-size: 19px;
  line-height: 1.85;
  color: var(--ink-2);
}

.band-dark .lede { color: rgba(242, 244, 243, 0.82); }

.title-xl { font-size: clamp(30px, 4.4vw, 46px); font-weight: 900; }
.title-lg { font-size: clamp(24px, 3vw, 32px); font-weight: 900; }
.title-md { font-size: 22px; }
.title-sm { font-size: 17px; }

.grid-texture {
  background-image:
    linear-gradient(var(--hair-2) 1px, transparent 1px),
    linear-gradient(90deg, var(--hair-2) 1px, transparent 1px);
  background-size: 32px 32px;
}

.glass-panel {
  background: var(--glass);
  backdrop-filter: blur(12px) saturate(140%);
  -webkit-backdrop-filter: blur(12px) saturate(140%);
  border: 1px solid rgba(255, 255, 255, 0.55);
  border-radius: 2px;
}

/* ---------- 5. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-ui);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.02em;
  padding: 11px 20px;
  border: 1px solid transparent;
  border-radius: 2px;
  transition: background var(--dur) var(--ease),
              color var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              transform var(--dur) var(--ease);
}

.btn:active { transform: translateY(1px); }

.btn-gold {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--ink);
}
.btn-gold:hover { background: var(--gold-lt); border-color: var(--gold-lt); }

.btn-ghost {
  border-color: var(--hair);
  color: var(--ink);
}
.btn-ghost:hover { border-color: var(--gold); color: var(--amber); }

.btn-teal {
  background: var(--teal);
  border-color: var(--teal);
  color: #fff;
}
.btn-teal:hover { background: var(--teal-dk); border-color: var(--teal-dk); }

.btn-quiet {
  border-color: var(--hair-dark);
  color: var(--paper);
}
.btn-quiet:hover { border-color: var(--gold-lt); color: var(--gold-lt); }

/* ---------- 6. 跳过链接 ---------- */
.skip-link {
  position: absolute;
  left: 16px;
  top: -64px;
  z-index: 200;
  display: inline-block;
  padding: 10px 18px;
  background: var(--ink);
  color: var(--gold-lt);
  border: 1px solid var(--gold);
  border-radius: 2px;
  font-family: var(--font-ui);
  font-size: 14px;
  transition: top 0.18s var(--ease);
}

.skip-link:focus { top: 12px; }

/* ---------- 7. 命令栏页头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--glass-dark);
  backdrop-filter: blur(14px) saturate(150%);
  -webkit-backdrop-filter: blur(14px) saturate(150%);
  border-bottom: 1px solid var(--hair-dark);
  color: var(--paper);
}

.cmd-bar {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 20px;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 14px 24px;
  transition: padding 0.22s var(--ease);
}

.site-header[data-scrolled] .cmd-bar {
  padding-top: 8px;
  padding-bottom: 8px;
}

/* 品牌 */
.brand {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-left: 14px;
  flex: none;
}

.brand::before {
  content: "";
  position: absolute;
  left: 0;
  top: 3px;
  bottom: 3px;
  width: 2px;
  background: linear-gradient(180deg, var(--gold) 0%, var(--gold) 45%, var(--teal) 100%);
}

.brand-mark {
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 900;
  letter-spacing: 0.02em;
  color: #fff;
  line-height: 1.2;
}

.brand-sub {
  display: block;
  font-family: var(--font-ui);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--gray);
  white-space: nowrap;
  line-height: 1.4;
  transition: opacity 0.2s var(--ease);
}

.site-header[data-scrolled] .brand-sub { opacity: 0; }

/* 导航 */
.site-nav { justify-self: center; }

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

.nav-item { display: block; }

.nav-link {
  position: relative;
  display: block;
  padding: 10px 12px;
  font-family: var(--font-ui);
  font-size: 14.5px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: rgba(242, 244, 243, 0.76);
  transition: color var(--dur) var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 12px;
  right: 12px;
  bottom: 2px;
  height: 2px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur) var(--ease);
}

.nav-link:hover { color: #fff; }
.nav-link:hover::after { transform: scaleX(1); }

.nav-link[aria-current="page"] {
  color: var(--gold-lt);
}
.nav-link[aria-current="page"]::after { transform: scaleX(1); }

/* 右侧动作区 */
.cmd-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  justify-self: end;
}

.cmd-current {
  display: none;
  font-family: var(--font-ui);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--gold-lt);
  white-space: nowrap;
}

.cmd-cta { padding: 10px 18px; }

.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 12px;
  border: 1px solid var(--hair-dark);
  border-radius: 2px;
  font-family: var(--font-ui);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--paper);
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}

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

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 16px;
  height: 12px;
}

.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 1.5px;
  background: currentColor;
  transition: transform 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.nav-toggle-bars::before { top: 0; box-shadow: 0 5px 0 0 currentColor; }
.nav-toggle-bars::after { bottom: 0; }

.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before {
  transform: translateY(5px) rotate(45deg);
  box-shadow: 0 0 0 0 transparent;
}

.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after {
  transform: translateY(-5px) rotate(-45deg);
}

/* 滚动进度 */
.progress-track {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 120;
  pointer-events: none;
  background: transparent;
}

.progress-bar {
  display: block;
  height: 100%;
  width: 100%;
  background: linear-gradient(90deg, var(--gold) 0%, var(--teal) 100%);
  transform: scaleX(0);
  transform-origin: 0 50%;
}

/* ---------- 8. 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-ui);
  border-top: 1px solid rgba(242, 244, 243, 0.08);
}

.site-footer::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 2px;
  background: linear-gradient(
    90deg,
    var(--gold) 0 34%,
    var(--teal) 34% 67%,
    var(--amber) 67% 100%
  );
}

.foot-shell {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 56px 24px 28px;
  display: grid;
  grid-template-columns: minmax(240px, 4fr) 8fr;
  gap: 40px 64px;
  align-items: start;
}

.foot-mark {
  display: block;
  font-family: var(--font-head);
  font-size: 21px;
  font-weight: 900;
  letter-spacing: 0.02em;
  color: #fff;
}

.foot-sub {
  display: block;
  margin-top: 9px;
  font-size: 12.5px;
  letter-spacing: 0.16em;
  color: var(--gold-lt);
}

.foot-contact {
  margin-top: 20px;
  font-size: 13.5px;
  line-height: 2;
  color: rgba(242, 244, 243, 0.7);
}

.foot-mono {
  font-family: var(--font-mono);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  color: var(--paper);
  word-break: break-all;
}

.foot-address {
  margin-top: 12px;
  max-width: 34ch;
  font-size: 13px;
  line-height: 1.9;
  color: var(--gray);
}

.foot-nav {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 28px;
}

.foot-title {
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--gold-lt);
  margin-bottom: 12px;
}

.foot-links a {
  display: inline-block;
  padding: 5px 0;
  font-size: 14.5px;
  color: rgba(242, 244, 243, 0.72);
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.foot-links a:hover {
  color: #fff;
  border-bottom-color: var(--gold);
}

.foot-base {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 18px 24px 44px;
  border-top: 1px solid var(--hair-dark);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 26px;
  font-size: 13px;
  color: var(--gray);
}

.foot-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

.foot-legal a {
  color: rgba(242, 244, 243, 0.72);
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.foot-legal a:hover {
  color: var(--gold-lt);
  border-bottom-color: var(--gold-lt);
}

.foot-icp { font-family: var(--font-mono); letter-spacing: 0.02em; }

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

/* ---------- 9. 面包屑 ---------- */
.crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0;
  padding-top: 18px;
  font-family: var(--font-ui);
  font-size: 13px;
  color: var(--gray);
}

.crumb li { display: flex; align-items: center; }

.crumb li + li::before {
  content: "／";
  margin: 0 8px;
  color: rgba(20, 22, 26, 0.25);
}

.crumb a { border-bottom: 1px solid var(--hair); }
.crumb a:hover { color: var(--amber); border-bottom-color: var(--gold); }

/* ---------- 10. 长文 ---------- */
.prose {
  max-width: 72ch;
  font-size: 17px;
  line-height: 1.9;
  color: var(--ink-2);
}

.prose h2 {
  font-size: 24px;
  margin: 2em 0 0.6em;
  color: var(--ink);
}

.prose h3 {
  font-size: 19px;
  margin: 1.6em 0 0.5em;
  color: var(--ink);
}

.prose a {
  color: var(--ink);
  border-bottom: 1px solid var(--gold);
}

.prose a:hover { color: var(--amber); }

.prose ul,
.prose ol {
  margin: 0 0 1.2em;
  padding-left: 1.3em;
  list-style: disc;
}

.prose ol { list-style: decimal; }
.prose li { margin: 0.4em 0; }

.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: rgba(20, 22, 26, 0.06);
  padding: 2px 6px;
  border-radius: 2px;
}

/* ---------- 11. 档案化组件 ---------- */
.archive-card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  background: var(--sheet);
  border: 1px solid var(--hair);
  border-left: 2px solid var(--gold);
  border-radius: 2px;
  padding: 20px 22px;
  transition: box-shadow var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.archive-card:hover {
  box-shadow: 0 10px 26px rgba(20, 22, 26, 0.07);
  border-left-color: var(--gold-lt);
}

.archive-card__no {
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: 0.06em;
  color: var(--gray);
}

.archive-card__title {
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.archive-card__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-ui);
  font-size: 12.5px;
  color: var(--gray);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  border: 1px solid transparent;
  border-radius: 2px;
  font-family: var(--font-ui);
  font-size: 12.5px;
  font-weight: 500;
  letter-spacing: 0.02em;
  white-space: nowrap;
}

.tag::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
  flex: none;
}

.tag-gold {
  background: rgba(195, 155, 39, 0.12);
  border-color: rgba(195, 155, 39, 0.38);
  color: #85690F;
}

.tag-teal {
  background: var(--teal-lt);
  border-color: rgba(46, 125, 107, 0.32);
  color: var(--teal-dk);
}

.tag-amber {
  background: rgba(169, 102, 10, 0.12);
  border-color: rgba(169, 102, 10, 0.34);
  color: #8A5407;
}

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

.spec-table {
  width: 100%;
  background: var(--sheet);
  border: 1px solid var(--hair);
  font-family: var(--font-ui);
  font-size: 14.5px;
}

.spec-table caption {
  caption-side: top;
  text-align: left;
  padding: 14px 16px;
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--ink);
  border-bottom: 1px solid var(--hair);
}

.spec-table th,
.spec-table td {
  padding: 12px 16px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid var(--hair);
}

.spec-table thead th {
  background: var(--ink-2);
  color: var(--paper);
  font-weight: 500;
  font-size: 13px;
  letter-spacing: 0.06em;
}

.spec-table tbody tr:last-child td { border-bottom: 0; }
.spec-table tbody tr:hover { background: rgba(195, 155, 39, 0.06); }

.spec-table .num {
  font-family: var(--font-mono);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.status-board {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 1px;
  background: var(--hair);
  border: 1px solid var(--hair);
}

.status-board__cell {
  background: var(--sheet);
  padding: 18px;
}

.status-board__label {
  font-family: var(--font-ui);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--gray);
}

.status-board__value {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 24px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
}

.band-dark .status-board { background: var(--hair-dark); border-color: var(--hair-dark); }
.band-dark .status-board__cell { background: var(--ink-2); }
.band-dark .status-board__label { color: var(--gray); }
.band-dark .status-board__value { color: var(--gold-lt); }

.stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(40px, 7vw, 84px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.03em;
  font-variant-numeric: tabular-nums;
  color: var(--ink);
}

.band-dark .stat-num { color: var(--gold-lt); }

/* ---------- 12. 分段切换 ---------- */
.tabs { width: 100%; }

.tablist {
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
  border-bottom: 1px solid var(--hair);
}

.tab {
  padding: 11px 16px;
  margin-bottom: -1px;
  border-bottom: 2px solid transparent;
  font-family: var(--font-ui);
  font-size: 14.5px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--gray);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

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

.tab[aria-selected="true"] {
  color: var(--ink);
  font-weight: 600;
  border-bottom-color: var(--gold);
}

.tabpanels { padding-top: 22px; }

.tabpanel[hidden] { display: none; }

.band-dark .tablist { border-bottom-color: var(--hair-dark); }
.band-dark .tab { color: rgba(242, 244, 243, 0.6); }
.band-dark .tab:hover { color: #fff; }
.band-dark .tab[aria-selected="true"] { color: var(--gold-lt); }

/* ---------- 13. 粘性索引 ---------- */
.sticky-index {
  position: sticky;
  top: 96px;
  align-self: start;
  padding-left: 16px;
  border-left: 1px solid var(--hair);
}

.index-link {
  display: block;
  margin-left: -17px;
  padding: 7px 0 7px 15px;
  border-left: 2px solid transparent;
  font-family: var(--font-ui);
  font-size: 13.5px;
  color: var(--gray);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.index-link:hover { color: var(--ink); }

.index-link[aria-current] {
  color: var(--ink);
  font-weight: 600;
  border-left-color: var(--gold);
}

/* ---------- 14. 折叠阅读 ---------- */
.fold {
  background: transparent;
  border-bottom: 1px solid var(--hair);
}

.fold summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-head);
  font-size: 16.5px;
  font-weight: 700;
  color: var(--ink);
}

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

.fold summary::after {
  content: "";
  flex: none;
  width: 9px;
  height: 9px;
  border-right: 2px solid var(--gold);
  border-bottom: 2px solid var(--gold);
  transform: rotate(45deg);
  transition: transform 0.2s var(--ease);
}

.fold[open] summary::after { transform: rotate(-135deg); }

.fold__body {
  padding: 0 0 20px;
  max-width: 68ch;
  font-size: 16px;
  color: var(--ink-2);
}

.band-dark .fold { border-bottom-color: var(--hair-dark); }
.band-dark .fold summary { color: #fff; }
.band-dark .fold__body { color: rgba(242, 244, 243, 0.78); }

/* ---------- 15. 显现 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.26s var(--ease), transform 0.26s var(--ease);
}

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

/* ---------- 16. 图片容器 ---------- */
.img-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: linear-gradient(135deg, #E7EBEA 0%, #DCE2E0 100%);
  border: 1px solid var(--hair);
  border-radius: 2px;
}

.img-frame > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.img-frame__cap {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  padding: 10px 14px;
  background: rgba(20, 22, 26, 0.82);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.04em;
}

.ratio-21x9 { aspect-ratio: 21 / 9; }
.ratio-16x9 { aspect-ratio: 16 / 9; }
.ratio-4x3  { aspect-ratio: 4 / 3; }
.ratio-3x4  { aspect-ratio: 3 / 4; }
.ratio-1x1  { aspect-ratio: 1 / 1; }

.img-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
}

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

/* ---------- 17. 响应式 ---------- */
@media (max-width: 1080px) {
  .g-5-7,
  .g-4-8,
  .g-3-6-3 { grid-template-columns: 1fr; }

  .sticky-index {
    position: static;
    border-left: 0;
    padding-left: 0;
  }

  .index-link {
    margin-left: 0;
    padding-left: 13px;
  }
}

@media (max-width: 980px) {
  .cmd-bar {
    grid-template-columns: 1fr auto;
    gap: 14px;
    padding: 12px 18px;
  }

  .site-header[data-scrolled] .cmd-bar {
    padding-top: 10px;
    padding-bottom: 10px;
  }

  .brand-sub { display: none; }

  .cmd-current { display: inline-block; }

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

  .site-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    max-height: 0;
    overflow: hidden;
    background: rgba(20, 22, 26, 0.97);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--hair-dark);
    transition: max-height 0.26s var(--ease);
  }

  .site-nav[data-open] { max-height: 560px; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 6px 18px 20px;
    max-width: var(--shell);
    margin: 0 auto;
  }

  .nav-link {
    padding: 14px 4px;
    font-size: 16px;
    border-bottom: 1px solid var(--hair-dark);
  }

  .nav-link::after {
    left: 4px;
    right: auto;
    bottom: 9px;
    width: 34px;
  }

  .foot-shell { grid-template-columns: 1fr; gap: 34px; }
}

@media (max-width: 720px) {
  body { font-size: 16.5px; }

  .shell { padding-left: 18px; padding-right: 18px; }

  .section { padding: 52px 0; }
  .section--tight { padding: 32px 0; }

  .cmd-cta { padding: 9px 14px; font-size: 13px; }
  .nav-toggle-text { display: none; }
  .nav-toggle { padding: 10px 11px; }

  .foot-shell { padding: 44px 18px 24px; }
  .foot-nav { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 26px 20px; }
  .foot-base { padding: 18px 18px 40px; }
  .foot-copy { margin-left: 0; }

  .img-grid--pair { grid-template-columns: 1fr; }

  .spec-table { font-size: 13.5px; }
  .spec-table th,
  .spec-table td { padding: 10px 12px; }
}

@media (max-width: 440px) {
  .foot-nav { grid-template-columns: 1fr; }
  .cmd-current { display: none; }
}

/* ---------- 18. 动效与无障碍降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

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

  .progress-bar { transition: none; }
}