/* ============================================================
   9博平台服务 · 共享站点样式 /assets/site.css
   丝路档案板：框架式导航 + 编号章节 + 精密网格
   ============================================================ */

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

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

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

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

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

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

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

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

/* ---------- 2. 变量 ---------- */
:root {
  --paper: #FBF7EF;
  --sand: #F0E6D2;
  --ink: #1C2836;
  --indigo: #2B3F55;
  --pomegranate: #B23A2F;
  --gold: #C9922E;
  --oasis: #1F6F8B;
  --slate: #6C7C8B;
  --line: #D9CDB8;
  --night: #12100D;

  --header-h: 76px;
  --rail-w: 56px;
  --shell: 1360px;
  --gutter: clamp(18px, 4vw, 48px);

  --font-head: "Noto Sans SC", "Source Han Sans SC", "PingFang SC",
               "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Noto Serif SC", "Source Han Serif SC", "Songti SC",
               "SimSun", Georgia, serif;

  --ease: cubic-bezier(.2, .7, .2, 1);
}

/* ---------- 3. 基础排版 ---------- */
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.85;
  letter-spacing: .002em;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 800;
  letter-spacing: -.02em;
  line-height: 1.14;
}

h1 { font-size: clamp(30px, 5vw, 58px); font-weight: 900; line-height: 1.05; }
h2 { font-size: clamp(24px, 3.2vw, 36px); }
h3 { font-size: 20px; line-height: 1.3; }

strong { font-weight: 700; }

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

/* ---------- 4. 可达性 ---------- */
:focus-visible {
  outline: 2px solid var(--pomegranate);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 200;
  padding: 11px 18px;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .04em;
  border: 1px solid var(--gold);
  transform: translateY(-180%);
  transition: transform .18s var(--ease);
}

.skip-link:focus,
.skip-link:focus-visible { transform: translateY(0); }

/* ---------- 5. 布局外壳 ---------- */
.site-main {
  display: block;
  padding-top: var(--header-h);
}

.shell {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.shell--narrow { max-width: 960px; }

.section {
  padding-block: clamp(44px, 6.5vw, 92px);
  border-top: 1px solid var(--line);
}

.section--sand { background: var(--sand); }
.section--quiet { background: #F5EFE3; }

.section--indigo {
  background: var(--indigo);
  color: var(--paper);
  border-top-color: var(--indigo);
}

.section--indigo .kicker { color: var(--gold); }
.section--indigo .kicker::before { background: var(--gold); }
.section--indigo .lede { color: rgba(251, 247, 239, .84); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 14px 28px;
  margin-bottom: clamp(20px, 3vw, 36px);
}

/* ---------- 6. 文本组件 ---------- */
.kicker {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--pomegranate);
}

.kicker::before {
  content: "";
  width: 18px;
  height: 2px;
  background: var(--pomegranate);
  flex: 0 0 auto;
}

.title-lg { font-size: clamp(28px, 4.4vw, 46px); line-height: 1.08; }
.title-md { font-size: clamp(22px, 3vw, 32px); line-height: 1.14; }
.title-sm { font-size: 19px; line-height: 1.3; }

.lede {
  font-size: clamp(16.5px, 1.7vw, 20px);
  line-height: 1.78;
  color: var(--indigo);
  max-width: 60ch;
}

.prose {
  max-width: 68ch;
  font-size: 16.5px;
  line-height: 1.85;
}

.prose h2 {
  font-size: clamp(21px, 2.5vw, 27px);
  margin: 1.9em 0 .55em;
}

.prose h3 {
  font-size: 19px;
  margin: 1.6em 0 .45em;
}

.prose p + p { margin-top: .95em; }
.prose p { text-align: justify; }

.prose ul,
.prose ol { margin: .85em 0; }

.prose li { margin-top: .4em; padding-left: 1.35em; position: relative; }

.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 7px;
  height: 7px;
  background: var(--gold);
  transform: rotate(45deg);
}

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

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

.prose strong { color: var(--ink); }

.prose blockquote {
  margin: 1.3em 0;
  padding: 4px 0 4px 18px;
  border-left: 3px solid var(--gold);
  font-family: var(--font-head);
  font-size: 15px;
  line-height: 1.75;
  color: var(--indigo);
}

/* ---------- 7. 网格 ---------- */
.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(16px, 2.2vw, 32px);
}

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

@media (min-width: 768px) {
  .col-4, .col-5, .col-6 { grid-column: span 6; }
  .col-7, .col-8 { grid-column: span 12; }
}

@media (min-width: 1024px) {
  .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; }
  .col-12 { grid-column: span 12; }
}

/* ---------- 8. 编号章节 ---------- */
.chapter-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(14px, 2.4vw, 30px);
  align-items: start;
  margin-bottom: clamp(22px, 3.6vw, 44px);
}

.chapter-index {
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(40px, 7vw, 78px);
  line-height: .86;
  letter-spacing: -.05em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.chapter-body { display: grid; gap: 12px; padding-top: 4px; }

@media (max-width: 639px) {
  .chapter-head { grid-template-columns: 1fr; }
}

/* ---------- 9. 卡片 / 信息块 ---------- */
.card {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 0;
  padding: clamp(18px, 2.4vw, 28px);
  transition: transform .18s var(--ease), border-color .18s var(--ease),
              box-shadow .18s var(--ease);
}

.card:hover,
.card:focus-within {
  transform: translateY(-2px);
  border-color: var(--pomegranate);
}

.card--sand { background: var(--sand); border-color: #DCCFB6; }

.card--indigo {
  background: var(--indigo);
  border-color: var(--indigo);
  color: var(--paper);
}

.card--indigo .lede,
.card--indigo p { color: rgba(251, 247, 239, .86); }

.card--focus {
  background: var(--paper);
  border: 1px solid var(--ink);
  box-shadow: 8px 8px 0 var(--sand);
}

/* ---------- 10. 数据 ---------- */
.stat {
  border-top: 2px solid var(--ink);
  padding-top: 12px;
}

.stat-num {
  display: block;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(27px, 3.8vw, 44px);
  line-height: 1;
  letter-spacing: -.035em;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.stat-label {
  display: block;
  margin-top: 8px;
  font-family: var(--font-head);
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: .05em;
  color: var(--slate);
}

.stat--accent .stat-num { color: var(--gold); }

/* ---------- 11. 标签 / 提示 / 列表 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border: 1px solid var(--line);
  background: var(--paper);
  font-family: var(--font-head);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: .08em;
  line-height: 1.5;
  color: var(--indigo);
}

.tag--red {
  background: var(--pomegranate);
  border-color: var(--pomegranate);
  color: var(--paper);
}

.tag--gold { border-color: var(--gold); color: #8A6417; }

.callout {
  border-left: 3px solid var(--gold);
  background: var(--sand);
  padding: 15px 20px;
  font-family: var(--font-head);
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--indigo);
}

.callout--red { border-left-color: var(--pomegranate); }

.list-tick li {
  position: relative;
  padding-left: 22px;
  font-size: 16px;
  line-height: 1.8;
}

.list-tick li + li { margin-top: 8px; }

.list-tick li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .74em;
  width: 8px;
  height: 8px;
  background: var(--gold);
  transform: rotate(45deg);
}

/* ---------- 12. 链接型入口 ---------- */
.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding-bottom: 2px;
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .01em;
  color: var(--oasis);
  background-image: linear-gradient(currentColor, currentColor);
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0 1px;
  transition: background-size .18s var(--ease), color .18s var(--ease);
}

.link-arrow::after {
  content: "→";
  transition: transform .18s var(--ease);
}

.link-arrow:hover,
.link-arrow:focus-visible { background-size: 100% 1px; }

.link-arrow:hover::after,
.link-arrow:focus-visible::after { transform: translateX(3px); }

/* ---------- 13. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 20px;
  border: 1px solid transparent;
  border-radius: 0;
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: .02em;
  text-align: center;
  transition: background .18s var(--ease), color .18s var(--ease),
              border-color .18s var(--ease);
}

.btn-primary {
  background: var(--pomegranate);
  border-color: var(--pomegranate);
  color: var(--paper);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}

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

.btn-ghost:hover,
.btn-ghost:focus-visible {
  background: var(--ink);
  color: var(--paper);
}

.btn-quiet {
  background: var(--sand);
  border-color: var(--line);
  color: var(--ink);
}

.btn-quiet:hover,
.btn-quiet:focus-visible {
  border-color: var(--ink);
  background: var(--paper);
}

.btn-sm { padding: 10px 14px; font-size: 13px; }
.btn-lg { padding: 16px 26px; font-size: 15px; }

/* ---------- 14. 筛选 chips ---------- */
.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  background: var(--paper);
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: .03em;
  line-height: 1.4;
  color: var(--indigo);
  transition: background .18s var(--ease), color .18s var(--ease),
              border-color .18s var(--ease);
}

.chip:hover,
.chip:focus-visible { border-color: var(--ink); }

.chip[aria-pressed="true"],
.chip.is-active {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}

/* ---------- 15. 图片容器 ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--sand);
  aspect-ratio: 16 / 9;
}

.media-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(28, 40, 54, 0) 42%, rgba(28, 40, 54, .30) 100%);
  pointer-events: none;
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame--duotone img { filter: grayscale(1) contrast(1.06); }

.media-frame--duotone::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: var(--indigo);
  mix-blend-mode: color;
  opacity: .58;
  pointer-events: none;
}

.media-caption {
  margin-top: 8px;
  font-family: var(--font-head);
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: .03em;
  color: var(--slate);
}

/* ---------- 16. 面包屑 ---------- */
.breadcrumb {
  font-family: var(--font-head);
  font-size: 12.5px;
  letter-spacing: .05em;
  color: var(--slate);
  padding-block: 18px 0;
}

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

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

.breadcrumb li + li::before {
  content: "/";
  color: var(--line);
}

.breadcrumb a {
  color: var(--oasis);
  border-bottom: 1px solid transparent;
  transition: border-color .18s var(--ease);
}

.breadcrumb a:hover { border-bottom-color: currentColor; }

.breadcrumb [aria-current="page"] {
  color: var(--ink);
  font-weight: 700;
}

/* ---------- 17. 装饰带 ---------- */
.geo-band {
  height: 8px;
  background-color: var(--sand);
  background-image:
    repeating-linear-gradient(135deg, var(--gold) 0 1px, transparent 1px 13px),
    repeating-linear-gradient(45deg, var(--line) 0 1px, transparent 1px 13px);
}

/* ============================================================
   18. 头部
   ============================================================ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 70;
  height: var(--header-h);
  background: var(--paper);
  border-bottom: 1px solid var(--ink);
}

.header-shell {
  width: 100%;
  max-width: var(--shell);
  height: 100%;
  margin: 0 auto;
  padding: 0 var(--gutter);
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.6vw, 26px);
}

/* 品牌 */
.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  flex: 0 0 auto;
  padding: 6px 0;
}

.brand-mark {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  background: var(--pomegranate);
  color: var(--paper);
  font-family: var(--font-head);
  font-size: 22px;
  font-weight: 900;
  line-height: 1;
  letter-spacing: 0;
  flex: 0 0 auto;
}

.brand-text { display: flex; flex-direction: column; gap: 3px; }

.brand-name {
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -.01em;
  color: var(--ink);
  white-space: nowrap;
}

.brand-tagline {
  font-family: var(--font-head);
  font-size: 10.5px;
  font-weight: 500;
  line-height: 1.3;
  letter-spacing: .06em;
  color: var(--slate);
  white-space: nowrap;
}

/* 导航 */
.site-nav {
  display: flex;
  align-items: center;
  margin-left: auto;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(6px, 1.1vw, 18px);
}

.nav-link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 5px;
  padding: 9px 2px;
  font-family: var(--font-head);
  font-size: clamp(13px, 1.02vw, 14.5px);
  font-weight: 600;
  line-height: 1.3;
  color: var(--ink);
  white-space: nowrap;
  transition: color .18s var(--ease);
}

.nav-index {
  font-size: 9.5px;
  font-weight: 900;
  letter-spacing: .04em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
  transition: color .18s var(--ease);
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 2px;
  height: 1px;
  background: var(--pomegranate);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform .18s var(--ease);
}

.nav-link:hover::after,
.nav-link:focus-visible::after { transform: scaleX(1); }

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

.nav-link[aria-current="page"]::after {
  transform: scaleX(1);
  height: 2px;
}

/* 头部右侧 */
.header-utility {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-left: clamp(10px, 1.6vw, 24px);
  padding-left: clamp(10px, 1.6vw, 22px);
  border-left: 1px solid var(--line);
  flex: 0 0 auto;
}

.utility-phone {
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--indigo);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.header-cta { white-space: nowrap; }

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  margin-left: auto;
  padding: 10px 12px;
  border: 1px solid var(--ink);
  background: var(--paper);
  flex: 0 0 auto;
}

.nav-toggle-bar {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: var(--ink);
  transition: background .18s var(--ease);
}

.nav-toggle-bar::before,
.nav-toggle-bar::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: var(--ink);
  transition: transform .2s var(--ease);
}

.nav-toggle-bar::before { top: -6px; }
.nav-toggle-bar::after { top: 6px; }

.nav-toggle-label {
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .08em;
  color: var(--ink);
}

[data-nav-toggle][aria-expanded="true"] .nav-toggle-bar { background: transparent; }
[data-nav-toggle][aria-expanded="true"] .nav-toggle-bar::before { transform: translateY(6px) rotate(45deg); }
[data-nav-toggle][aria-expanded="true"] .nav-toggle-bar::after { transform: translateY(-6px) rotate(-45deg); }

/* 面板内的电话与 CTA（仅移动端可见） */
.nav-foot {
  display: none;
  flex-direction: column;
  gap: 10px;
  margin-top: 22px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.nav-foot-phone {
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 900;
  letter-spacing: .01em;
  color: var(--indigo);
  font-variant-numeric: tabular-nums;
}

.nav-foot-cta { width: 100%; }

.nav-foot-note {
  font-family: var(--font-head);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--slate);
}

/* 滚动进度线 */
.scroll-meter {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  pointer-events: none;
  background: transparent;
}

.scroll-meter-fill {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--gold), var(--pomegranate));
  transition: width .1s linear;
}

/* 左侧书脊导轨 */
.frame-spine { display: none; }

/* ============================================================
   19. 页脚
   ============================================================ */
.site-footer {
  background: var(--night);
  color: var(--paper);
  border-top: 1px solid var(--night);
}

.footer-rule {
  height: 4px;
  background: linear-gradient(90deg,
    var(--gold) 0 33.34%,
    var(--pomegranate) 33.34% 66.67%,
    var(--oasis) 66.67% 100%);
}

.footer-shell {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: clamp(38px, 5.5vw, 68px) var(--gutter) clamp(28px, 4vw, 46px);
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 4vw, 52px);
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.footer-brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  background: var(--pomegranate);
  color: var(--paper);
  font-family: var(--font-head);
  font-size: 19px;
  font-weight: 900;
  line-height: 1;
  flex: 0 0 auto;
}

.footer-brand-name {
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--paper);
}

.footer-statement {
  margin-top: 16px;
  max-width: 40ch;
  font-size: 14.5px;
  line-height: 1.9;
  color: rgba(251, 247, 239, .78);
}

.footer-update {
  display: flex;
  align-items: center;
  gap: 9px;
  margin-top: 18px;
  font-family: var(--font-head);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--gold);
}

.footer-update-dot {
  width: 6px;
  height: 6px;
  background: var(--gold);
  flex: 0 0 auto;
}

.footer-nav {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 34px);
}

.footer-col-title {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 12px;
  font-family: var(--font-head);
  font-size: 12.5px;
  font-weight: 800;
  letter-spacing: .12em;
  color: var(--paper);
}

.footer-col-index {
  font-size: 9.5px;
  font-weight: 900;
  letter-spacing: .04em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.footer-list li + li { margin-top: 2px; }

.footer-link {
  display: inline-block;
  padding: 5px 0;
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 500;
  line-height: 1.6;
  color: rgba(251, 247, 239, .78);
  background-image: linear-gradient(var(--gold), var(--gold));
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0 1px;
  transition: background-size .18s var(--ease), color .18s var(--ease);
}

.footer-link:hover,
.footer-link:focus-visible {
  color: var(--paper);
  background-size: 100% 1px;
}

.footer-contact li {
  font-family: var(--font-head);
  font-size: 12.8px;
  line-height: 1.9;
  letter-spacing: .01em;
  color: rgba(251, 247, 239, .62);
}

.footer-contact li + li { margin-top: 4px; }

.footer-base {
  max-width: var(--shell);
  margin: 0 auto;
  padding: 16px var(--gutter) 26px;
  border-top: 1px solid rgba(251, 247, 239, .16);
  display: flex;
  flex-wrap: wrap;
  gap: 6px 26px;
  justify-content: space-between;
  font-family: var(--font-head);
  font-size: 12px;
  letter-spacing: .04em;
  color: rgba(251, 247, 239, .52);
}

.footer-legal { color: rgba(251, 247, 239, .66); }

/* ============================================================
   20. 滚动显现
   ============================================================ */
.has-js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity .32s var(--ease), transform .32s var(--ease);
}

.has-js [data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}

/* ============================================================
   21. 响应式
   ============================================================ */
@media (min-width: 768px) {
  .footer-shell { grid-template-columns: 1fr 1fr; }
  .footer-lead { grid-column: 1 / -1; }
  .footer-nav { grid-column: 1 / -1; grid-template-columns: repeat(3, 1fr); }
  .footer-meta { grid-column: 1 / -1; }
}

@media (min-width: 1024px) {
  .footer-shell {
    grid-template-columns: 1.05fr 1.75fr .95fr;
    align-items: start;
  }
  .footer-lead { grid-column: auto; }
  .footer-nav { grid-column: auto; }
  .footer-meta { grid-column: auto; }
}

@media (min-width: 1180px) {
  body { padding-left: var(--rail-w); }

  .site-header { padding-left: var(--rail-w); }

  .frame-spine {
    display: block;
    position: fixed;
    top: var(--header-h);
    left: 0;
    bottom: 0;
    width: var(--rail-w);
    border-right: 1px solid var(--ink);
    z-index: 65;
    pointer-events: none;
  }

  .spine-mark {
    position: absolute;
    top: 24px;
    left: 50%;
    transform: translateX(-50%);
    writing-mode: vertical-rl;
    font-family: var(--font-head);
    font-size: 10px;
    font-weight: 900;
    letter-spacing: .32em;
    line-height: 1;
    color: var(--slate);
    white-space: nowrap;
  }

  .spine-ticks {
    position: absolute;
    top: 190px;
    bottom: 32px;
    left: 50%;
    width: 1px;
    transform: translateX(-50%);
    background-image: repeating-linear-gradient(
      to bottom,
      var(--line) 0 1px,
      transparent 1px 24px
    );
  }

  .spine-ticks::after {
    content: "";
    position: absolute;
    bottom: -10px;
    left: -4px;
    width: 9px;
    height: 9px;
    background: var(--gold);
  }
}

@media (max-width: 1319px) {
  .utility-phone { display: none; }
  .header-utility { padding-left: clamp(10px, 1.4vw, 18px); }
}

@media (max-width: 1023px) {
  .nav-toggle { display: inline-flex; }
  .header-utility { display: none; }

  .site-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    z-index: 68;
    display: none;
    flex-direction: column;
    align-items: stretch;
    margin: 0;
    padding: 10px var(--gutter) 26px;
    background: var(--paper);
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--ink);
    max-height: calc(100vh - var(--header-h));
    overflow-y: auto;
  }

  .site-nav[data-open] { display: flex; }

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

  .nav-link {
    justify-content: flex-start;
    gap: 10px;
    padding: 15px 6px;
    font-size: 16.5px;
    font-weight: 700;
    border-bottom: 1px solid var(--line);
  }

  .nav-index { font-size: 10.5px; }

  .nav-link::after { display: none; }

  .nav-link[aria-current="page"] {
    box-shadow: inset 3px 0 0 var(--pomegranate);
    padding-left: 14px;
    color: var(--pomegranate);
  }

  .nav-foot { display: flex; }
}

@media (max-width: 767px) {
  :root { --header-h: 62px; }

  body { font-size: 16px; }

  .brand-mark { width: 34px; height: 34px; font-size: 19px; }
  .brand-name { font-size: 15.5px; }
  .brand-tagline { display: none; }

  .footer-nav { grid-template-columns: 1fr 1fr; }
  .footer-base { justify-content: flex-start; }
}

@media (max-width: 479px) {
  .footer-nav { grid-template-columns: 1fr; }
}

/* ============================================================
   22. 减弱动效
   ============================================================ */
@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;
  }

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

  .card:hover,
  .card:focus-within { transform: none; }

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