/* ==========================================================================
   永丽皇宫品牌 · 共享样式表  /assets/site.css
   档案库视觉系统：深海蓝 / 鎏金 / 珍珠白 · 非对称编辑部栅格
   ========================================================================== */

/* ---------- 1. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; }
img, svg, video { display: block; max-width: 100%; }
img { height: auto; }
svg { fill: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; cursor: pointer; }
a { color: inherit; }
ul, ol { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4, h5, h6, p, figure, blockquote, dl, dd { margin: 0; }
table { border-collapse: collapse; width: 100%; }
[hidden] { display: none !important; }

/* ---------- 2. 设计令牌 ---------- */
:root {
  /* 色板 */
  --navy-royal: #061A2E;
  --navy-court: #0E2C4A;
  --index-blue: #1B4A72;
  --gold: #C9A552;
  --gold-light: #E7CE8F;
  --coral: #E2725B;
  --pearl: #F6F1E6;
  --paper: #EDE3D0;
  --ink: #12171E;
  --slate: #6E7F92;

  /* 字体 */
  --serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  --sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --mono: "IBM Plex Mono", "JetBrains Mono", "SFMono-Regular", "Consolas", "Liberation Mono", monospace;

  /* 尺度 */
  --shell: 1200px;
  --gutter: clamp(16px, 4vw, 40px);
  --header-h: 104px;

  /* 线条 */
  --line: rgba(110, 127, 146, 0.34);
  --line-gold: rgba(201, 165, 82, 0.42);
  --line-gold-soft: rgba(201, 165, 82, 0.20);

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

/* ---------- 3. 基础排版 ---------- */
body {
  background: var(--navy-royal);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.75;
  padding-top: var(--header-h);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
@media (min-width: 768px) { body { font-size: 17px; } }
@media (min-width: 1280px) { body { font-size: 18px; } }

main, #main-content {
  display: block;
  background: var(--pearl);
  min-height: 50vh;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--serif);
  font-weight: 700;
  line-height: 1.24;
  letter-spacing: -0.02em;
  color: var(--navy-royal);
}
h1 { font-size: clamp(2rem, 5.4vw, 3.6rem); }
h2 { font-size: clamp(1.5rem, 3.4vw, 2.25rem); }
h3 { font-size: clamp(1.15rem, 2.2vw, 1.5rem); }
h4 { font-size: 1.05rem; letter-spacing: 0; }

.tone-dark h1, .tone-dark h2, .tone-dark h3, .tone-dark h4 { color: var(--pearl); }
.tone-dark { color: rgba(246, 241, 230, 0.82); }

a { color: var(--index-blue); text-decoration: none; }
a:hover { color: var(--coral); }

strong { font-weight: 700; color: var(--navy-royal); }
.tone-dark strong { color: var(--gold-light); }

::selection { background: var(--gold); color: var(--navy-royal); }

:focus-visible {
  outline: 2px solid var(--gold-light);
  outline-offset: 3px;
}
.tone-dark :focus-visible,
.site-header :focus-visible,
.site-footer :focus-visible { outline-color: var(--gold); }

/* ---------- 4. 布局工具 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  position: relative;
  padding-block: clamp(48px, 7vw, 96px);
}
.section--dark { background: var(--navy-royal); color: rgba(246, 241, 230, 0.82); }
.section--court { background: var(--navy-court); color: rgba(246, 241, 230, 0.82); }
.section--pearl { background: var(--pearl); }
.section--paper { background: var(--paper); }
.section--band {
  background: linear-gradient(160deg, var(--navy-court) 0%, var(--navy-royal) 70%);
  color: rgba(246, 241, 230, 0.82);
}
.section--band::after {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(90deg, rgba(201, 165, 82, 0.06) 0 1px, transparent 1px 72px);
  pointer-events: none;
}
.section--band > * { position: relative; z-index: 1; }

/* 非对称编辑部栅格：左 3 索引 · 右 9 内容 */
.editorial {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 48px);
}
@media (min-width: 1024px) {
  .editorial {
    grid-template-columns: minmax(190px, 3fr) minmax(0, 9fr);
    gap: clamp(32px, 4vw, 64px);
  }
  .editorial__aside {
    position: sticky;
    top: calc(var(--header-h) + 24px);
    align-self: start;
  }
}

/* ---------- 5. 索引元素 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 14px;
}
.eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background: var(--gold);
  flex: 0 0 auto;
}

.index-num {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--gold);
  padding-right: 10px;
  border-right: 1px solid var(--line-gold);
  margin-right: 10px;
}

.rule {
  height: 1px;
  border: 0;
  margin: 0;
  background: linear-gradient(90deg, var(--gold) 0%, rgba(201, 165, 82, 0.12) 60%, transparent 100%);
}

.tag {
  display: inline-block;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.10em;
  padding: 3px 9px;
  border: 1px solid var(--line-gold);
  color: var(--gold);
  background: rgba(201, 165, 82, 0.08);
  white-space: nowrap;
}
.tag--coral {
  border-color: var(--coral);
  color: var(--coral);
  background: rgba(226, 114, 91, 0.10);
}

/* ---------- 6. 纸张叠层卡片 ---------- */
.paper-card {
  position: relative;
  padding: clamp(20px, 3vw, 32px);
  background: transparent;
}
.paper-card::before {
  content: "";
  position: absolute;
  inset: 8px -8px -8px 8px;
  background: var(--paper);
  border: 1px solid var(--line-gold-soft);
}
.paper-card::after {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--pearl);
  border: 1px solid var(--line);
}
.paper-card > * { position: relative; z-index: 1; }

.tone-dark .paper-card::before { background: rgba(201, 165, 82, 0.10); }
.tone-dark .paper-card::after { background: var(--navy-court); border-color: var(--line-gold-soft); }

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: 1px solid var(--gold);
  background: var(--gold);
  color: var(--navy-royal);
  font-family: var(--sans);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-decoration: none;
  transition: background-color 0.2s var(--ease), border-color 0.2s var(--ease), color 0.2s var(--ease), transform 0.2s var(--ease);
}
.btn:hover {
  background: var(--gold-light);
  border-color: var(--gold-light);
  color: var(--navy-royal);
  transform: translateY(-1px);
}
.btn--ghost {
  background: transparent;
  color: var(--gold);
}
.btn--ghost:hover {
  background: rgba(201, 165, 82, 0.14);
  color: var(--gold-light);
  border-color: var(--gold-light);
}
.btn--coral {
  background: var(--coral);
  border-color: var(--coral);
  color: #ffffff;
}
.btn--coral:hover {
  background: #d3634c;
  border-color: #d3634c;
  color: #ffffff;
}

/* ---------- 8. 面包屑 ---------- */
.breadcrumb {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--slate);
  padding-block: 18px;
  border-bottom: 1px solid var(--line);
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}
.breadcrumb li { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumb li + li::before {
  content: "/";
  color: var(--gold);
}
.breadcrumb a { color: var(--index-blue); }
.breadcrumb a:hover { color: var(--coral); }
.breadcrumb [aria-current="page"] { color: var(--ink); }

/* ---------- 9. 正文容器 ---------- */
.prose {
  max-width: 68ch;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--ink);
}
.prose > * + * { margin-top: 1.2em; }
.prose h2, .prose h3 { margin-top: 2em; }
.prose a {
  color: var(--index-blue);
  text-decoration: underline;
  text-decoration-color: var(--gold-light);
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}
.prose a:hover { color: var(--coral); text-decoration-color: var(--coral); }
.prose ul, .prose ol { padding-left: 1.4em; }
.prose ul li { list-style: none; position: relative; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: -1.1em;
  top: 0.72em;
  width: 6px;
  height: 1px;
  background: var(--gold);
}
.prose ol { list-style: decimal; }
.prose ol li { list-style: decimal; }
.tone-dark .prose { color: rgba(246, 241, 230, 0.80); }
.tone-dark .prose a { color: var(--gold-light); }

/* ---------- 10. 图片容器（页面阶段放 img） ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  isolation: isolate;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--line-gold);
  background:
    radial-gradient(120% 90% at 20% 10%, rgba(201, 165, 82, 0.16), transparent 60%),
    linear-gradient(140deg, var(--navy-court) 0%, var(--navy-royal) 100%);
}
.media-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background: repeating-linear-gradient(135deg, rgba(201, 165, 82, 0.08) 0 1px, transparent 1px 14px);
}
.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--portrait { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame__caption {
  margin-top: 12px;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--slate);
}
@media (min-width: 1024px) {
  .media-frame { aspect-ratio: 16 / 9; }
  .media-frame--wide { aspect-ratio: 21 / 9; }
  .media-frame--portrait { aspect-ratio: 3 / 4; }
  .media-frame--square { aspect-ratio: 1 / 1; }
}

/* ---------- 11. 数据点 ---------- */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1px;
  background: var(--line-gold-soft);
  border: 1px solid var(--line-gold-soft);
}
.stat {
  background: var(--pearl);
  padding: 20px 22px;
}
.tone-dark .stat { background: var(--navy-court); }
.stat__key {
  display: block;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--slate);
  margin-bottom: 8px;
}
.stat__val {
  display: block;
  font-family: var(--mono);
  font-size: clamp(1.5rem, 3vw, 2rem);
  line-height: 1.1;
  color: var(--navy-royal);
  border-bottom: 2px solid var(--gold);
  padding-bottom: 6px;
}
.tone-dark .stat__val { color: var(--gold-light); }

/* ---------- 12. 折叠面板 ---------- */
.collapse {
  border: 1px solid var(--line);
  background: var(--pearl);
}
.collapse + .collapse { border-top: 0; }
.collapse > summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 18px 22px;
  cursor: pointer;
  list-style: none;
  font-family: var(--serif);
  font-weight: 600;
  color: var(--navy-royal);
  transition: background-color 0.2s var(--ease), color 0.2s var(--ease);
}
.collapse > summary::-webkit-details-marker { display: none; }
.collapse > summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--mono);
  color: var(--gold);
  font-size: 16px;
}
.collapse[open] > summary::after { content: "–"; }
.collapse > summary:hover { background: var(--paper); }
.collapse__body {
  padding: 0 22px 22px;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--ink);
}

/* ---------- 13. 跳至主要内容 ---------- */
.skip-link {
  position: absolute;
  left: 12px;
  top: -100px;
  z-index: 999;
  padding: 10px 18px;
  background: var(--gold);
  color: var(--navy-royal);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  transition: top 0.2s var(--ease);
}
.skip-link:focus { top: 12px; color: var(--navy-royal); }

/* ==========================================================================
   14. 页头
   ========================================================================== */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 100;
  background: transparent;
  transition: background-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}
.site-header.is-solid {
  background: var(--navy-court);
  box-shadow: 0 18px 36px -26px rgba(0, 0, 0, 0.95);
}

.masthead {
  height: 72px;
  display: flex;
  align-items: center;
}
.masthead__inner {
  display: flex;
  align-items: center;
  gap: clamp(12px, 2vw, 28px);
  height: 100%;
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  text-decoration: none;
  color: var(--pearl);
}
.brand:hover { color: var(--pearl); }
.brand__mark {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border: 1px solid var(--gold);
  color: var(--gold);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  background: rgba(6, 26, 46, 0.5);
}
.brand__word {
  font-family: var(--serif);
  font-weight: 700;
  font-size: 22px;
  letter-spacing: 0.12em;
  white-space: nowrap;
}

/* 主导航 */
.main-nav {
  flex: 1 1 auto;
  display: flex;
  justify-content: center;
}
.main-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}
.main-nav__list a {
  position: relative;
  display: block;
  padding: 9px 10px;
  font-size: 14px;
  letter-spacing: 0.04em;
  color: rgba(246, 241, 230, 0.76);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.18s var(--ease);
}
.main-nav__list a::after {
  content: "";
  position: absolute;
  left: 10px;
  right: 10px;
  bottom: 2px;
  height: 1px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.2s var(--ease);
}
.main-nav__list a:hover { color: var(--gold-light); }
.main-nav__list a:hover::after { transform: scaleX(1); }
.main-nav__list a[aria-current="page"] { color: var(--gold); }
.main-nav__list a[aria-current="page"]::after { transform: scaleX(1); }

/* 头部工具 */
.header-tools {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
}
.tool {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 8px 12px;
  border: 1px solid var(--line-gold);
  background: rgba(6, 26, 46, 0.42);
  color: rgba(246, 241, 230, 0.88);
  font-family: var(--sans);
  font-size: 13px;
  letter-spacing: 0.04em;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}
.tool:hover {
  color: var(--gold-light);
  border-color: var(--gold);
  background: rgba(201, 165, 82, 0.14);
}
.tool__icon {
  width: 15px;
  height: 15px;
  flex: 0 0 auto;
  color: var(--gold);
}
.tool--star[aria-pressed="true"] .tool__icon,
.tool--star:hover .tool__icon { color: var(--coral); }

/* 移动端菜单按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 8px 12px;
  border: 1px solid var(--line-gold);
  background: rgba(6, 26, 46, 0.42);
  color: var(--pearl);
  font-family: var(--sans);
  font-size: 13px;
  letter-spacing: 0.08em;
  flex: 0 0 auto;
}
.nav-toggle__bars {
  display: grid;
  gap: 4px;
  width: 16px;
}
.nav-toggle__bars span {
  display: block;
  height: 1px;
  background: var(--gold);
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}
.nav-toggle[aria-expanded="true"] { border-color: var(--gold); background: rgba(201, 165, 82, 0.16); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }

/* 索引带 */
.index-band {
  height: 32px;
  overflow: hidden;
  display: flex;
  align-items: center;
  border-top: 1px solid var(--line-gold-soft);
  background: rgba(6, 26, 46, 0.55);
  transition: background-color 0.2s var(--ease);
}
.site-header.is-solid .index-band { background: rgba(6, 26, 46, 0.94); }
.index-band__track {
  display: flex;
  align-items: center;
  gap: 40px;
  padding-left: var(--gutter);
  width: max-content;
  white-space: nowrap;
  animation: band-scroll 52s linear infinite;
}
.index-band__item {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: rgba(231, 206, 143, 0.72);
  text-decoration: none;
}
.index-band__item--link {
  color: var(--gold-light);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.index-band__item--link:hover {
  color: var(--coral);
  border-bottom-color: var(--coral);
}
@keyframes band-scroll {
  from { transform: translateX(0); }
  to { transform: translateX(-50%); }
}

/* 站内索引面板 */
.search-panel {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  padding-block: 22px 24px;
  background: var(--navy-court);
  border-top: 1px solid var(--line-gold);
  border-bottom: 1px solid var(--line-gold);
  box-shadow: 0 30px 50px -34px rgba(0, 0, 0, 0.95);
}
.search-panel__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
}
.search-panel__input {
  flex: 1 1 300px;
  min-width: 0;
  padding: 12px 16px;
  background: rgba(6, 26, 46, 0.92);
  border: 1px solid var(--line-gold);
  color: var(--pearl);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.04em;
}
.search-panel__input::placeholder { color: var(--slate); }
.search-panel__hint {
  flex: 0 0 100%;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--slate);
}

/* ==========================================================================
   15. 页脚
   ========================================================================== */
.site-footer {
  position: relative;
  background: var(--navy-royal);
  color: rgba(246, 241, 230, 0.78);
  border-top: 1px solid var(--line-gold);
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    repeating-linear-gradient(90deg, rgba(201, 165, 82, 0.05) 0 1px, transparent 1px 64px),
    radial-gradient(90% 70% at 12% 0%, rgba(201, 165, 82, 0.10), transparent 62%);
}
.site-footer .shell { position: relative; z-index: 1; }

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 34px;
  padding-block: 52px 34px;
}
@media (min-width: 640px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 40px; }
}
@media (min-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1.7fr 1fr 1fr 1fr;
    gap: 48px;
    padding-block: 72px 48px;
  }
}

.footer-col { min-width: 0; }
.footer-col__title {
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 400;
  letter-spacing: 0.20em;
  color: var(--gold);
  margin-bottom: 16px;
}
.footer-lede {
  margin-top: 18px;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(246, 241, 230, 0.66);
  max-width: 34ch;
}
.footer-contact { margin-top: 22px; }
.footer-contact li {
  display: flex;
  flex-direction: column;
  gap: 3px;
  padding-block: 10px;
  border-top: 1px dashed rgba(201, 165, 82, 0.22);
}
.footer-contact__key {
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.16em;
  color: var(--slate);
}
.footer-contact__val {
  font-size: 13px;
  line-height: 1.7;
  color: rgba(246, 241, 230, 0.86);
  word-break: break-word;
}
.footer-links li + li { margin-top: 10px; }
.footer-links a {
  font-size: 14px;
  color: rgba(246, 241, 230, 0.70);
  border-bottom: 1px solid transparent;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.footer-links a:hover {
  color: var(--gold-light);
  border-bottom-color: var(--line-gold);
}

.footer-base {
  border-top: 1px solid rgba(201, 165, 82, 0.20);
  padding-block: 18px 26px;
}
.footer-base__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 12px 20px;
  text-align: center;
}
.footer-base__meta {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--slate);
}
.to-top {
  padding: 8px 16px;
  border: 1px solid var(--line-gold);
  color: var(--gold);
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background-color 0.18s var(--ease);
}
.to-top:hover {
  color: var(--navy-royal);
  background: var(--gold);
  border-color: var(--gold);
}

/* ---------- 16. 滚动显现 ---------- */
.has-js [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.34s var(--ease), transform 0.34s var(--ease);
}
.has-js [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

/* ==========================================================================
   17. 响应式
   ========================================================================== */
@media (max-width: 1023px) {
  :root { --header-h: 96px; }

  .masthead { height: 64px; }
  .brand__word { font-size: 19px; }
  .brand__mark { width: 32px; height: 32px; font-size: 10px; }
  .header-tools { margin-left: auto; }

  .main-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    flex: none;
    display: block;
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
    background: var(--navy-court);
    border-top: 1px solid var(--line-gold);
    box-shadow: 0 30px 50px -30px rgba(0, 0, 0, 0.95);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity 0.2s var(--ease), transform 0.2s var(--ease), visibility 0.2s linear;
  }
  .main-nav[data-open="true"] {
    opacity: 1;
    visibility: visible;
    transform: none;
  }
  .main-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 6px var(--gutter) 24px;
  }
  .main-nav__list a {
    padding: 15px 0;
    font-size: 16px;
    border-bottom: 1px solid rgba(201, 165, 82, 0.18);
  }
  .main-nav__list a::after { display: none; }
  .main-nav__list a[aria-current="page"] {
    color: var(--gold);
    padding-left: 12px;
    border-left: 2px solid var(--gold);
  }

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

@media (max-width: 767px) {
  :root { --header-h: 86px; }

  .masthead { height: 56px; }
  .masthead__inner { gap: 10px; }
  .brand__word { font-size: 17px; letter-spacing: 0.08em; }
  .brand__mark { width: 28px; height: 28px; font-size: 9px; }
  .brand { gap: 8px; }

  .tool { padding: 8px 10px; }
  .tool__label { display: none; }
  .nav-toggle__label { display: none; }

  .index-band { height: 30px; }
  .index-band__track { gap: 26px; animation-duration: 64s; }
  .index-band__item { font-size: 10px; }

  .search-panel__inner { gap: 8px 0; }
  .search-panel__input { flex: 1 1 100%; font-size: 12px; }

  .paper-card { padding: 18px; }
  .paper-card::before { inset: 5px -5px -5px 5px; }
}

/* ---------- 18. 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .index-band__track { animation: none; }
  .has-js [data-reveal],
  .has-js [data-reveal].is-in {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .skip-link,
  .site-header,
  .main-nav,
  .tool,
  .btn,
  .nav-toggle__bars span,
  .footer-links a {
    transition-duration: 0.001ms;
  }
  .btn:hover { transform: none; }
}