/* ============================================================
   贝投指南 · 丝路数字驿站 / 共享站点样式 ( /assets/site.css )
   1. 重置  2. 变量  3. 基础排版  4. 头部  5. 页脚
   6. 通用组件  7. 显现动效  8. 响应式  9. 无障碍降级
   ============================================================ */

/* ---------- 1. 重置 ---------- */
*,
*::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 {
  margin: 0;
}

ul, ol { padding: 0; 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; }

::selection { background: rgba(201, 162, 39, .35); color: #1E1B18; }

/* ---------- 2. 变量 ---------- */
:root {
  /* 品牌色 */
  --clay: #9E3B2A;
  --clay-deep: #6E2A1E;
  --clay-dark: #4A1B13;
  --bronze: #2F5D50;
  --bronze-light: #4E8474;
  --sand: #F3EADD;
  --paper: #FBF6EC;
  --gold: #C9A227;
  --stone: #4A4642;
  --ink: #1E1B18;
  --terracotta: #C2704F;
  --moss: #7C8C5A;

  /* 线条与描边 */
  --line: rgba(30, 27, 24, .14);
  --line-strong: rgba(30, 27, 24, .28);
  --paper-line: rgba(251, 246, 236, .22);

  /* 字体 */
  --serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", Georgia, serif;
  --sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* 尺寸 */
  --wrap: 1200px;
  --gutter: clamp(18px, 4vw, 44px);
  --bar-h: 34px;
  --head-h: 80px;
  --radius: 2px;
  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 3. 基础排版 ---------- */
body {
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.75;
  color: var(--stone);
  background-color: var(--sand);
  background-image: radial-gradient(rgba(30, 27, 24, .05) 1px, transparent 1px);
  background-size: 5px 5px;
  padding-top: calc(var(--bar-h) + var(--head-h));
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--serif);
  font-weight: 800;
  color: var(--ink);
  line-height: 1.18;
  letter-spacing: .01em;
}

p { text-wrap: pretty; }

:focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 3px;
  border-radius: 1px;
}

#main-content { scroll-margin-top: calc(var(--bar-h) + var(--head-h) + 12px); }

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ---------- 4. 头部 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 500;
  transform: translateY(-240%);
  background: var(--ink);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: .04em;
  padding: 11px 18px;
  border-radius: var(--radius);
  transition: transform .18s var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible { transform: translateY(0); }

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 300;
  background: rgba(243, 234, 221, .74);
  -webkit-backdrop-filter: blur(10px) saturate(1.08);
  backdrop-filter: blur(10px) saturate(1.08);
  transition: background-color .22s var(--ease), box-shadow .22s var(--ease);
}
.site-header[data-scrolled],
.site-header[data-nav-open] {
  background: var(--paper);
  box-shadow: 0 1px 0 var(--line), 0 18px 34px -30px rgba(30, 27, 24, .75);
}

/* 发布条 */
.announce-bar {
  height: var(--bar-h);
  display: flex;
  align-items: center;
  overflow: hidden;
  background: var(--clay-deep);
  color: #F0E2D2;
  transition: height .22s var(--ease), opacity .18s var(--ease);
}
.site-header[data-scrolled] .announce-bar { height: 0; opacity: 0; }

.announce-inner {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: .02em;
}
.announce-dot {
  flex: 0 0 auto;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 3px rgba(201, 162, 39, .22);
}
.announce-text {
  flex: 1 1 auto;
  min-width: 0;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: #EFE0CE;
}
.announce-link {
  flex: 0 0 auto;
  margin-left: auto;
  color: var(--gold);
  border-bottom: 1px solid rgba(201, 162, 39, .5);
  padding-bottom: 1px;
  white-space: nowrap;
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.announce-link:hover { color: #FFF8EC; border-color: #FFF8EC; }

/* 主导航条 */
.masthead {
  position: relative;
  border-bottom: 1px solid transparent;
  transition: border-color .22s var(--ease);
}
.site-header[data-scrolled] .masthead { border-bottom-color: var(--line); }

.masthead-inner {
  display: flex;
  align-items: center;
  gap: clamp(14px, 2.4vw, 34px);
  min-height: var(--head-h);
  padding-block: 10px;
  transition: min-height .22s var(--ease), padding .22s var(--ease);
}
.site-header[data-scrolled] .masthead-inner { min-height: 62px; padding-block: 6px; }

/* 品牌印章 */
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
}
.brand-seal {
  flex: 0 0 auto;
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 900;
  line-height: 1;
  color: var(--paper);
  background: var(--clay);
  border: 1px solid var(--clay-deep);
  border-radius: var(--radius);
  box-shadow: 3px 3px 0 rgba(110, 42, 30, .28);
  transition: background-color .18s var(--ease), box-shadow .18s var(--ease);
}
.brand:hover .brand-seal {
  background: var(--clay-deep);
  box-shadow: 4px 4px 0 rgba(110, 42, 30, .34);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-name {
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 900;
  letter-spacing: .03em;
  color: var(--ink);
}
.brand-sub {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--bronze);
}

/* 导航 */
.nav {
  flex: 1 1 auto;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: clamp(12px, 2vw, 26px);
  margin-left: auto;
}
.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(2px, 1.2vw, 18px);
}
.nav-link {
  position: relative;
  display: inline-block;
  padding: 9px 4px;
  font-size: 15px;
  letter-spacing: .02em;
  color: var(--stone);
  transition: color .18s var(--ease);
}
.nav-link::after {
  content: "";
  position: absolute;
  left: 4px;
  right: 4px;
  bottom: 3px;
  height: 2px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .2s var(--ease), background-color .18s var(--ease);
}
.nav-link:hover { color: var(--clay); }
.nav-link:hover::after { transform: scaleX(1); }
.nav-link[aria-current="page"] {
  color: var(--clay-deep);
  font-weight: 600;
}
.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--clay);
}

.header-actions {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 10px;
}

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  flex: 0 0 auto;
  margin-left: auto;
  width: 44px;
  height: 42px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  background: var(--paper);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  cursor: pointer;
  transition: background-color .18s var(--ease), border-color .18s var(--ease);
}
.nav-toggle:hover { border-color: var(--clay); background: #FFFDF7; }
.nav-toggle-bar {
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
  transition: transform .22s var(--ease), opacity .18s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* 阅读进度 */
.scroll-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), var(--terracotta));
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform .1s linear;
  pointer-events: none;
}

/* ---------- 5. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 96px);
  background-color: var(--clay-deep);
  background-image: repeating-linear-gradient(135deg, rgba(251, 246, 236, .045) 0 1px, transparent 1px 9px);
  color: #EADCCB;
}
.footer-ridge {
  height: 6px;
  background: repeating-linear-gradient(90deg, var(--gold) 0 14px, rgba(201, 162, 39, .32) 14px 28px);
}
.footer-inner { padding-block: clamp(38px, 6vw, 72px) 24px; }

.footer-top {
  display: grid;
  grid-template-columns: minmax(240px, 1fr) minmax(0, 1.65fr);
  gap: clamp(28px, 4vw, 64px);
  padding-bottom: clamp(26px, 4vw, 44px);
  border-bottom: 1px solid var(--paper-line);
}

.footer-brand { min-width: 0; }
.footer-seal {
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 900;
  line-height: 1;
  color: var(--clay-deep);
  background: var(--paper);
  border-radius: var(--radius);
  box-shadow: 4px 4px 0 rgba(30, 27, 24, .3);
}
.footer-name {
  margin-top: 16px;
  font-family: var(--serif);
  font-size: clamp(24px, 3vw, 30px);
  font-weight: 900;
  line-height: 1.2;
  letter-spacing: .04em;
  color: var(--paper);
}
.footer-line {
  margin-top: 6px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: rgba(251, 246, 236, .68);
}
.footer-copy {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}
.copy-btn {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .04em;
  padding: 7px 12px;
  color: #EADCCB;
  background: transparent;
  border: 1px solid rgba(251, 246, 236, .35);
  border-radius: var(--radius);
  cursor: pointer;
  transition: color .18s var(--ease), border-color .18s var(--ease), background-color .18s var(--ease);
}
.copy-btn:hover { color: var(--gold); border-color: var(--gold); }
.copy-btn[data-copied] {
  color: var(--gold);
  border-color: var(--gold);
  background: rgba(201, 162, 39, .16);
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 40px);
}
.footer-col { min-width: 0; }
.footer-col-title {
  margin-bottom: 14px;
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .14em;
  color: var(--gold);
}
.footer-list { display: grid; gap: 9px; }
.footer-link {
  font-size: 15px;
  line-height: 1.6;
  color: rgba(251, 246, 236, .82);
  transition: color .18s var(--ease);
}
.footer-link:hover {
  color: #FFFDF7;
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-color: var(--gold);
}
.footer-link--mono {
  font-family: var(--mono);
  font-size: 13.5px;
  letter-spacing: .01em;
  word-break: break-word;
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 24px;
  padding-top: 22px;
  font-size: 13px;
  color: rgba(251, 246, 236, .62);
}
.footer-note { flex: 1 1 320px; line-height: 1.7; font-size: 13px; }
.footer-legal { font-family: var(--mono); letter-spacing: .02em; }
.footer-sign { font-family: var(--serif); color: rgba(251, 246, 236, .82); }
.footer-year { font-family: var(--mono); margin-left: auto; white-space: nowrap; }

/* 返回顶部 */
.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 28px);
  bottom: clamp(14px, 3vw, 28px);
  z-index: 240;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  font-family: var(--mono);
  font-size: 18px;
  color: var(--clay-deep);
  background: var(--paper);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  box-shadow: 3px 3px 0 rgba(110, 42, 30, .3);
  cursor: pointer;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity .22s var(--ease), transform .22s var(--ease), visibility .22s var(--ease),
              background-color .18s var(--ease), color .18s var(--ease);
}
.to-top[data-visible] { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { background: var(--clay); color: var(--paper); border-color: var(--clay-deep); }

/* ---------- 6. 通用组件 ---------- */
.section { padding-block: clamp(44px, 7vw, 88px); }
.section--tight { padding-block: clamp(28px, 4vw, 48px); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: 14px 28px;
  margin-bottom: clamp(22px, 3vw, 36px);
  padding-bottom: 16px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  margin-bottom: 10px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--bronze);
}
.eyebrow::before {
  content: "";
  width: 24px;
  height: 2px;
  background: var(--gold);
  flex: 0 0 auto;
}

.display-title {
  font-size: clamp(38px, 7vw, 72px);
  line-height: 1.05;
  letter-spacing: -.012em;
  color: var(--ink);
}
.section-title {
  font-size: clamp(24px, 3.4vw, 34px);
  line-height: 1.2;
  color: var(--ink);
}
.lede {
  max-width: 62ch;
  font-size: clamp(16px, 1.6vw, 18.5px);
  line-height: 1.8;
  color: var(--stone);
}

.prose { max-width: 68ch; }
.prose p { font-size: 17px; line-height: 1.85; }
.prose p + p { margin-top: 1em; }
.prose h2,
.prose h3 { margin-top: 1.5em; margin-bottom: .5em; }
.prose ul,
.prose ol { margin-top: .8em; display: grid; gap: 8px; }
.prose ul li { position: relative; padding-left: 20px; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72em;
  width: 8px;
  height: 8px;
  background: var(--gold);
  border-radius: 1px;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 16px;
  font-family: var(--mono);
  font-size: 13px;
  line-height: 1;
  letter-spacing: .03em;
  white-space: nowrap;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  transition: transform .18s var(--ease), background-color .18s var(--ease), color .18s var(--ease),
              box-shadow .18s var(--ease), border-color .18s var(--ease);
}
.btn-solid {
  color: var(--paper);
  background: var(--clay);
  border-color: var(--clay-deep);
  box-shadow: 3px 3px 0 rgba(110, 42, 30, .35);
}
.btn-solid:hover {
  background: var(--clay-deep);
  transform: translate(-1px, -1px);
  box-shadow: 4px 4px 0 rgba(110, 42, 30, .42);
}
.btn-solid:active { transform: translate(1px, 1px); box-shadow: 1px 1px 0 rgba(110, 42, 30, .42); }

.btn-ghost {
  color: var(--ink);
  background: transparent;
  border-color: var(--line-strong);
}
.btn-ghost:hover {
  color: var(--clay-deep);
  background: var(--paper);
  border-color: var(--clay);
}

.btn-gold {
  color: var(--ink);
  background: var(--gold);
  border-color: #A8871B;
  box-shadow: 3px 3px 0 rgba(30, 27, 24, .2);
}
.btn-gold:hover {
  background: #B8931F;
  transform: translate(-1px, -1px);
  box-shadow: 4px 4px 0 rgba(30, 27, 24, .24);
}

.btn-quiet {
  color: var(--bronze);
  background: var(--paper);
  border-color: var(--bronze-light);
}
.btn-quiet:hover {
  color: var(--paper);
  background: var(--bronze);
  border-color: var(--bronze);
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
}

/* 纸张卡片 */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--paper);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  box-shadow: 4px 4px 0 rgba(110, 42, 30, .09);
}
.card--clay {
  color: var(--paper);
  background: var(--clay);
  border-color: var(--clay-deep);
  box-shadow: 4px 4px 0 rgba(110, 42, 30, .22);
}
.card--clay .card-title { color: var(--paper); }
.card--bronze {
  color: var(--paper);
  background: var(--bronze);
  border-color: #25493F;
  box-shadow: 4px 4px 0 rgba(47, 93, 80, .22);
}
.card--bronze .card-title { color: var(--paper); }
.card--stack {
  box-shadow: 4px 4px 0 rgba(110, 42, 30, .1), 8px 8px 0 rgba(47, 93, 80, .14);
}
.card-title {
  font-family: var(--serif);
  font-size: clamp(19px, 2vw, 23px);
  font-weight: 800;
  line-height: 1.3;
  color: var(--ink);
}

/* 标签 */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--bronze);
  background: rgba(78, 132, 116, .1);
  border: 1px solid var(--bronze-light);
  border-radius: var(--radius);
}
.tag--gold {
  color: #8A6E12;
  background: rgba(201, 162, 39, .16);
  border-color: #B8931F;
}
.tag--clay {
  color: var(--clay);
  background: rgba(194, 112, 79, .14);
  border-color: var(--terracotta);
}
.tag--moss {
  color: #5A6A3E;
  background: rgba(124, 140, 90, .16);
  border-color: var(--moss);
}

/* 大号序号 */
.index-number {
  display: block;
  font-family: var(--serif);
  font-size: clamp(40px, 6vw, 72px);
  font-weight: 900;
  line-height: 1;
  letter-spacing: -.03em;
  color: rgba(158, 59, 42, .2);
}

/* 分隔线 */
.rule {
  height: 1px;
  margin-block: clamp(28px, 4vw, 48px);
  border: 0;
  background: var(--line);
}
.rule--gold {
  height: 2px;
  background: linear-gradient(90deg, var(--gold), rgba(201, 162, 39, 0));
}

/* 网格 */
.grid { display: grid; gap: clamp(16px, 2.4vw, 28px); }
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.grid--split { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }
.grid--split-rev { grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); }

/* 面包屑 */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding-block: 14px;
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: .04em;
  color: rgba(74, 70, 66, .9);
}
.breadcrumbs li { display: flex; align-items: center; gap: 8px; }
.breadcrumbs li + li::before {
  content: "/";
  color: rgba(30, 27, 24, .3);
}
.breadcrumbs a {
  color: var(--bronze);
  border-bottom: 1px solid transparent;
  transition: border-color .18s var(--ease), color .18s var(--ease);
}
.breadcrumbs a:hover { color: var(--bronze); border-bottom-color: var(--bronze); }
.breadcrumbs [aria-current="page"] { color: var(--stone); font-weight: 500; }

/* 图像容器（页面阶段放置图片占位） */
.media {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 9;
  background-color: var(--paper);
  background-image: linear-gradient(135deg, rgba(194, 112, 79, .18), rgba(47, 93, 80, .16));
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
}
.media > img,
.media > svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: sepia(.12) saturate(.92) contrast(1.02);
}
.media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: .55;
  mix-blend-mode: multiply;
  background-image: repeating-linear-gradient(45deg, rgba(30, 27, 24, .05) 0 1px, transparent 1px 6px);
}
.media--wide { aspect-ratio: 21 / 9; }
.media--square { aspect-ratio: 1 / 1; }
.media--tall { aspect-ratio: 3 / 4; }
.media--framed {
  padding: 8px;
  background: var(--paper);
  box-shadow: 6px 6px 0 rgba(47, 93, 80, .16);
}
.media--framed > img { border: 1px solid var(--line); }
.media-caption {
  margin-top: 8px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: rgba(74, 70, 66, .8);
}

/* ---------- 7. 显现动效 ---------- */
.has-js .reveal {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity .6s var(--ease), transform .6s var(--ease);
}
.has-js .reveal.is-visible {
  opacity: 1;
  transform: none;
}
.reveal-stagger > *:nth-child(1) { transition-delay: 0ms; }
.reveal-stagger > *:nth-child(2) { transition-delay: 70ms; }
.reveal-stagger > *:nth-child(3) { transition-delay: 140ms; }
.reveal-stagger > *:nth-child(4) { transition-delay: 210ms; }
.reveal-stagger > *:nth-child(5) { transition-delay: 280ms; }
.reveal-stagger > *:nth-child(6) { transition-delay: 350ms; }
.reveal-stagger > *:nth-child(7) { transition-delay: 420ms; }
.reveal-stagger > *:nth-child(8) { transition-delay: 490ms; }

/* ---------- 8. 响应式 ---------- */
@media (max-width: 1180px) {
  .header-actions .btn-ghost { display: none; }
  .nav-link { font-size: 14.5px; }
}

@media (max-width: 1080px) {
  .brand-sub { display: none; }
}

@media (max-width: 960px) {
  :root { --bar-h: 30px; --head-h: 68px; }

  body { font-size: 16px; }

  .announce-inner { font-size: 11.5px; }
  .announce-text { flex: 1 1 auto; }

  .nav-toggle { display: flex; }

  .nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    display: none;
    flex: none;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
    margin-left: 0;
    padding: 8px var(--gutter) 22px;
    background: var(--paper);
    border-top: 1px solid var(--line);
    border-bottom: 2px solid var(--clay);
    box-shadow: 0 26px 44px -30px rgba(30, 27, 24, .7);
    max-height: calc(100vh - var(--head-h) - var(--bar-h));
    overflow-y: auto;
  }
  .nav[data-open] { display: flex; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .nav-list li + li { border-top: 1px solid var(--line); }

  .nav-link {
    display: block;
    padding: 14px 12px;
    font-size: 16px;
  }
  .nav-link::after { display: none; }
  .nav-link[aria-current="page"] {
    padding-left: 10px;
    color: var(--clay-deep);
    background: rgba(158, 59, 42, .07);
    border-left: 3px solid var(--clay);
  }
  .nav-link:hover { color: var(--clay); background: rgba(158, 59, 42, .04); }

  .header-actions {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
    margin-top: 18px;
    padding-top: 18px;
    border-top: 1px dashed var(--line-strong);
  }
  .header-actions .btn,
  .header-actions .btn-ghost { display: inline-flex; width: 100%; padding: 14px; }

  .site-header[data-scrolled] .masthead-inner { min-height: 56px; padding-block: 5px; }

  .grid--split,
  .grid--split-rev { grid-template-columns: 1fr; }

  .footer-top { grid-template-columns: 1fr; }
  .footer-cols { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-meta { gap: 8px 18px; }
  .footer-year { margin-left: 0; }
}

@media (max-width: 620px) {
  .announce-link { display: none; }
  .brand-name { font-size: 18px; }
  .brand-seal { width: 36px; height: 36px; font-size: 18px; }
  .footer-cols { grid-template-columns: 1fr; }
  .footer-seal { width: 46px; height: 46px; font-size: 21px; }
  .display-title { font-size: clamp(32px, 10vw, 44px); }
  .media--framed { padding: 6px; }
  .to-top { width: 42px; height: 42px; }
}

@media (max-width: 400px) {
  body { font-size: 15.5px; }
  .announce-text { font-size: 11px; }
}

/* ---------- 9. 无障碍降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    transition-delay: 0ms !important;
    scroll-behavior: auto !important;
  }

  .has-js .reveal,
  .has-js .reveal.is-visible {
    opacity: 1;
    transform: none;
  }

  .to-top { transform: none; }
  .scroll-progress { transition: none; }
}