/* ============================================================
   仲博客户端 · 共享站点样式  /assets/site.css
   设计母题：极简文字建筑 + 丝路驿站指引地图
   分区：重置 / 变量 / 排版 / 基础组件 / 头部 / 页脚 / 响应式 / 动效降级
   ============================================================ */

/* ---------- 1. 重置 ---------- */
*,
*::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, dl, dd, figure, blockquote, fieldset {
  margin: 0;
}

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  cursor: pointer;
}

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

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

[id] { scroll-margin-top: calc(var(--header-h) + 16px); }

/* ---------- 2. 变量 ---------- */
:root {
  /* 色彩 */
  --night: #101A3C;
  --indigo: #1B2A5E;
  --indigo-soft: #2C3E7A;
  --gold: #D6A756;
  --gold-mist: #F0D9A8;
  --gold-wash: #F8EFD8;
  --celadon: #5FA8A0;
  --celadon-mist: #D9ECE9;
  --paper: #FAF7F1;
  --ink: #1C1F26;
  --stone: #6E7484;
  --hair: #D8D3C8;
  --clay: #B4573F;

  /* 字体 */
  --font-heading: "HarmonyOS Sans SC", "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", Georgia, "Times New Roman", serif;
  --font-mono: "JetBrains Mono", "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;

  /* 尺度 */
  --container: 1280px;
  --gutter: 48px;
  --measure: 34em;
  --header-h: 118px;

  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;
  --space-4: 32px;
  --space-5: 48px;
  --space-6: 72px;
  --space-7: 96px;

  --hairline: 1px solid var(--hair);
  --dur: 240ms;
  --ease: cubic-bezier(.22, .61, .36, 1);
}

/* ---------- 3. 基础排版 ---------- */
html, body { min-height: 100%; }

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-heading);
  font-size: 17px;
  line-height: 1.75;
  letter-spacing: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

#main-content { flex: 1 0 auto; }

h1, h2, h3, h4 {
  font-family: var(--font-heading);
  color: var(--indigo);
  font-weight: 700;
  line-height: 1.12;
  letter-spacing: -0.01em;
  text-wrap: balance;
}

h1 { font-size: clamp(40px, 6vw, 72px); }
h2 { font-size: clamp(28px, 3.6vw, 44px); font-weight: 650; }
h3 { font-size: 24px; line-height: 1.28; }
h4 { font-size: 19px; line-height: 1.35; }

p { line-height: 1.75; }

strong { font-weight: 600; color: var(--indigo); }

a {
  color: var(--indigo);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-decoration-color: var(--hair);
  text-underline-offset: 3px;
  transition: color var(--dur) var(--ease), text-decoration-color var(--dur) var(--ease);
}

a:hover { text-decoration-color: var(--gold); color: var(--indigo-soft); }

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

.section--deep :focus-visible,
.site-footer :focus-visible,
.header-utility :focus-visible {
  outline-color: var(--gold-mist);
}

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

/* ---------- 4. 容器与区块 ---------- */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container--narrow {
  width: 100%;
  max-width: 860px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: var(--space-7); }
.section--tight { padding-block: var(--space-6); }

.section--deep {
  background: var(--night);
  color: #DDE1EC;
}
.section--deep h1,
.section--deep h2,
.section--deep h3 { color: #FAF7F1; }
.section--deep strong { color: var(--gold-mist); }
.section--deep a { color: var(--gold-mist); text-decoration-color: rgba(240, 217, 168, .45); }

.section--sand { background: var(--gold-wash); }

/* ---------- 5. 文字工具 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--stone);
}
.eyebrow::before {
  content: "";
  width: 24px;
  height: 1px;
  background: var(--gold);
  flex: none;
}

.lede {
  font-size: clamp(17px, 1.6vw, 20px);
  line-height: 1.7;
  color: var(--ink);
  max-width: var(--measure);
}

.mono {
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  font-size: 0.95em;
}

.serif {
  font-family: var(--font-serif);
  letter-spacing: 0;
}

.rule {
  display: block;
  height: 1px;
  border: 0;
  background: var(--hair);
  margin-block: var(--space-4);
}

/* ---------- 6. 正文长文 ---------- */
.prose {
  max-width: var(--measure);
  color: var(--ink);
}
.prose > * + * { margin-top: 1.1em; }
.prose h2 {
  font-size: clamp(24px, 2.6vw, 30px);
  margin-top: 2em;
  font-weight: 650;
}
.prose h3 {
  font-size: 20px;
  margin-top: 1.8em;
  font-weight: 600;
}
.prose ul,
.prose ol {
  padding-left: 1.3em;
  list-style: disc;
}
.prose ol { list-style: decimal; }
.prose li + li { margin-top: 0.5em; }
.prose li::marker { color: var(--gold); }
.prose blockquote {
  border-left: 2px solid var(--gold);
  padding-left: 20px;
  font-family: var(--font-serif);
  color: var(--indigo);
}
.prose code {
  font-family: var(--font-mono);
  font-size: 0.92em;
  background: var(--gold-wash);
  padding: 1px 6px;
}

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: 0;
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: 0.02em;
  text-decoration: none;
  text-align: center;
  transition: background-color var(--dur) var(--ease),
              color var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}
.btn:hover { text-decoration: none; }

.btn--primary {
  background: var(--gold);
  border-color: var(--gold);
  color: var(--night);
}
.btn--primary:hover {
  background: var(--gold-mist);
  border-color: var(--gold-mist);
  color: var(--night);
}

.btn--ghost {
  background: transparent;
  border-color: var(--indigo);
  color: var(--indigo);
}
.btn--ghost:hover {
  background: var(--indigo);
  border-color: var(--indigo);
  color: var(--paper);
}

.section--deep .btn--ghost,
.site-footer .btn--ghost {
  border-color: var(--gold-mist);
  color: var(--gold-mist);
}
.section--deep .btn--ghost:hover,
.site-footer .btn--ghost:hover {
  background: var(--gold-mist);
  color: var(--night);
}

.btn--quiet {
  padding: 0;
  border: 0;
  background: none;
  color: var(--indigo);
  text-decoration: underline;
  text-decoration-color: var(--gold);
  text-underline-offset: 4px;
}

.btn--block {
  display: flex;
  width: 100%;
}

/* ---------- 8. 信息块与提示 ---------- */
.panel {
  padding: var(--space-4);
  border: var(--hairline);
  border-radius: 0;
  background: #FFFFFF;
}
.panel--sand { background: var(--gold-wash); border-color: #E4D2A6; }
.panel--celadon { background: var(--celadon-mist); border-color: #B9DAD5; }
.panel--night {
  background: var(--night);
  border-color: rgba(214, 167, 86, .42);
  color: #E7EAF3;
}
.panel--night h2,
.panel--night h3 { color: #FAF7F1; }

.notice {
  display: block;
  padding: 14px 18px;
  border-left: 3px solid var(--celadon);
  background: var(--celadon-mist);
  color: #20423E;
  font-size: 14px;
  line-height: 1.7;
}
.notice--gold {
  border-left-color: var(--gold);
  background: var(--gold-wash);
  color: #5C4213;
}
.notice--clay {
  border-left-color: var(--clay);
  background: #F6E3DD;
  color: #6B2E1F;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid var(--hair);
  border-radius: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--stone);
  background: transparent;
}
.tag--gold { border-color: var(--gold); color: #86601D; background: var(--gold-wash); }
.tag--celadon { border-color: var(--celadon); color: #2F5F5A; background: var(--celadon-mist); }

/* ---------- 9. 网格与骨架 ---------- */
.grid { display: grid; gap: var(--space-4); }
.grid--two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--auto { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }

.split {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: var(--space-4);
}
.split__rail { grid-column: 1 / span 3; }
.split__stream { grid-column: 5 / span 8; }

.rail {
  position: sticky;
  top: calc(var(--header-h) + 16px);
  align-self: start;
}

.band {
  display: flex;
  flex-wrap: wrap;
  border-top: var(--hairline);
  border-bottom: var(--hairline);
}
.band__item {
  flex: 1 1 160px;
  padding: 18px 20px;
  border-right: var(--hairline);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--indigo);
}
.band__item:last-child { border-right: 0; }

/* ---------- 10. 步骤轨道 ---------- */
.step-rail {
  margin-left: 8px;
  border-left: 1px solid var(--hair);
}
.step {
  position: relative;
  padding: 0 0 var(--space-4) var(--space-4);
}
.step:last-child { padding-bottom: 0; }
.step::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 10px;
  width: 7px;
  height: 7px;
  background: var(--paper);
  border: 1px solid var(--indigo);
  transform: rotate(45deg);
}
.step[data-state="current"]::before {
  background: var(--gold);
  border-color: var(--gold);
}
.step__index {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--stone);
}
.step__title {
  display: block;
  margin-top: 6px;
  font-size: 20px;
  font-weight: 600;
  color: var(--indigo);
}
.step__text {
  margin-top: 8px;
  max-width: 32em;
  font-size: 15px;
  color: #3A3F4A;
}

/* ---------- 11. 时间轴 ---------- */
.timeline {
  display: grid;
  gap: var(--space-3);
  padding-left: var(--space-3);
  border-left: 1px solid var(--hair);
}
.timeline__item { position: relative; }
.timeline__item::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--space-3) - 3px);
  top: 10px;
  width: 7px;
  height: 7px;
  background: var(--gold);
}
.timeline__date {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--stone);
}
.timeline__title {
  display: block;
  margin-top: 4px;
  font-size: 18px;
  font-weight: 600;
  color: var(--indigo);
}
.timeline__text {
  margin-top: 6px;
  max-width: 32em;
  font-size: 15px;
  color: #3A3F4A;
}

/* ---------- 12. 标签页 ---------- */
.tabs__list {
  display: flex;
  flex-wrap: wrap;
  border-bottom: var(--hairline);
}
.tabs__tab {
  margin-bottom: -1px;
  padding: 12px 20px;
  border-bottom: 2px solid transparent;
  font-size: 14px;
  font-weight: 600;
  color: var(--stone);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.tabs__tab:hover { color: var(--indigo); }
.tabs__tab[aria-selected="true"] {
  color: var(--indigo);
  border-bottom-color: var(--gold);
}
.tabs__panel { padding-top: var(--space-3); }
.tabs__panel[hidden] { display: none; }

/* ---------- 13. 手风琴（原生 details） ---------- */
.accordion { border-top: var(--hairline); }
.accordion__item { border-bottom: var(--hairline); }
.accordion__summary {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  padding: 18px 0;
  list-style: none;
  cursor: pointer;
  font-family: var(--font-heading);
  font-size: 17px;
  font-weight: 600;
  color: var(--indigo);
}
.accordion__summary::-webkit-details-marker { display: none; }
.accordion__summary::after {
  content: "";
  flex: none;
  width: 11px;
  height: 11px;
  margin-top: 6px;
  border-right: 1.5px solid var(--gold);
  border-bottom: 1.5px solid var(--gold);
  transform: rotate(45deg);
  transition: transform var(--dur) var(--ease);
}
.accordion__item[open] .accordion__summary::after { transform: rotate(-135deg); }
.accordion__body {
  padding-bottom: 20px;
  max-width: var(--measure);
  font-size: 15px;
  line-height: 1.75;
  color: #3A3F4A;
}

/* ---------- 14. 面包屑 ---------- */
.breadcrumb { font-size: 13px; color: var(--stone); }
.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}
.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  color: var(--hair);
}
.breadcrumb__link {
  color: var(--indigo);
  text-decoration-color: var(--hair);
}
.breadcrumb__link:hover { text-decoration-color: var(--gold); }
.breadcrumb__current { color: var(--stone); }

/* ---------- 15. 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  border: var(--hairline);
  background:
    linear-gradient(135deg, var(--celadon-mist) 0%, var(--paper) 55%, var(--gold-wash) 100%);
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(27, 42, 94, .08) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(27, 42, 94, .08) 1px, transparent 1px);
  background-size: 32px 32px;
}
.media-frame__inner {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
}
.media-frame__inner img,
.media-frame__inner svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--wide .media-frame__inner { aspect-ratio: 21 / 9; }
.media-frame--tall .media-frame__inner { aspect-ratio: 3 / 4; }
.media-frame--square .media-frame__inner { aspect-ratio: 1 / 1; }
.media-frame__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--stone);
}

/* ---------- 16. 跳过链接 ---------- */
.skip-link {
  position: absolute;
  left: var(--gutter);
  top: -120px;
  z-index: 220;
  padding: 10px 18px;
  background: var(--gold);
  color: var(--night);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  transition: top var(--dur) var(--ease);
}
.skip-link:focus { top: 8px; }

/* ---------- 17. 头部：双层信息导航 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: var(--paper);
}

.header-utility {
  background: var(--night);
  color: #EDE7DA;
}

.header-utility__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  min-height: 52px;
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: #F4EFE4;
  text-decoration: none;
}
.brand-mark:hover { color: var(--gold-mist); text-decoration: none; }

.brand-mark__glyph {
  position: relative;
  flex: none;
  width: 15px;
  height: 15px;
  border: 1px solid var(--gold);
  transform: rotate(45deg);
}
.brand-mark__glyph::after {
  content: "";
  position: absolute;
  inset: 3px;
  background: var(--gold);
  opacity: .92;
}

.brand-mark__text {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 6px 14px;
}
.brand-mark__name {
  font-family: var(--font-heading);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: #FAF7F1;
}
.brand-mark__tagline {
  font-size: 12px;
  letter-spacing: 0.02em;
  color: #A9B2CC;
}

.header-shortcuts {
  display: flex;
  align-items: center;
  gap: 26px;
}
.header-shortcut {
  position: relative;
  padding-block: 4px;
  font-size: 13px;
  color: #C9D0E4;
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}
.header-shortcut::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur) var(--ease);
}
.header-shortcut:hover,
.header-shortcut:focus-visible { color: var(--gold-mist); }
.header-shortcut:hover::after,
.header-shortcut:focus-visible::after { transform: scaleX(1); }

.header-main {
  background: var(--paper);
  border-bottom: 1px solid var(--hair);
  transition: box-shadow var(--dur) var(--ease);
}

.header-main__inner {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  min-height: 64px;
}

.header-main__label {
  flex: none;
  padding-right: 14px;
  border-right: 1px solid var(--hair);
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1;
  letter-spacing: 0.18em;
  color: var(--stone);
}

.site-nav {
  flex: 1 1 auto;
  min-width: 0;
}
.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 2px;
}
.site-nav__link {
  position: relative;
  display: inline-block;
  padding: 8px 14px;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: 0.01em;
  color: var(--indigo);
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}
.site-nav__link::after {
  content: "";
  position: absolute;
  left: 14px;
  right: 14px;
  bottom: 2px;
  height: 2px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur) var(--ease);
}
.site-nav__link:hover { color: var(--indigo); }
.site-nav__link:hover::after,
.site-nav__link:focus-visible::after { transform: scaleX(1); }
.site-nav__link[aria-current="page"] {
  font-weight: 700;
  color: var(--night);
}
.site-nav__link[aria-current="page"]::after { transform: scaleX(1); }

.site-nav__top { display: none; }
.site-nav__foot { display: none; }

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: none;
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 9px 14px;
  border: 1px solid var(--indigo);
  color: var(--indigo);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.04em;
}
.nav-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 3px;
  width: 16px;
}
.nav-toggle__bars span {
  display: block;
  height: 1.5px;
  background: currentColor;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}

.nav-backdrop {
  position: fixed;
  inset: 0;
  z-index: 70;
  background: rgba(16, 26, 60, .55);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--dur) var(--ease);
}

.header-progress {
  position: relative;
  height: 2px;
  background: rgba(216, 211, 200, .5);
}
.header-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 80ms linear;
}

.site-header[data-stuck="true"] .header-main {
  box-shadow: 0 1px 0 var(--hair), 0 14px 26px -22px rgba(16, 26, 60, .65);
}

/* ---------- 18. 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--night);
  color: #D3D8E6;
}
.site-footer::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 1px;
  background: linear-gradient(90deg, transparent 0%, var(--gold) 30%, var(--gold) 70%, transparent 100%);
  opacity: .65;
}

.footer-grid {
  display: grid;
  grid-template-columns: 4fr 2fr 2fr 3.5fr;
  gap: var(--space-5) var(--space-4);
  padding-block: var(--space-6);
}

.footer-brand__line {
  font-family: var(--font-heading);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: #FAF7F1;
}
.footer-brand__desc {
  margin-top: 14px;
  max-width: 30em;
  font-size: 14px;
  line-height: 1.75;
  color: #A8B0C6;
}

.footer-col__title {
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold);
  line-height: 1.4;
}

.footer-links li + li { margin-top: 10px; }

.footer-link {
  position: relative;
  display: inline-block;
  padding-bottom: 2px;
  font-size: 14px;
  color: #C6CCDD;
  text-decoration: none;
  transition: color var(--dur) var(--ease);
}
.footer-link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: var(--gold);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur) var(--ease);
}
.footer-link:hover { color: var(--gold-mist); }
.footer-link:hover::after,
.footer-link:focus-visible::after { transform: scaleX(1); }

.footer-contact__list {
  display: grid;
  gap: 14px;
}
.footer-contact__row { display: grid; gap: 2px; }
.footer-contact__row dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: #8A93AC;
}
.footer-contact__row dd {
  margin: 0;
  font-size: 14px;
  line-height: 1.65;
  color: #E4E7F1;
  word-break: break-word;
}
.footer-contact__row dd.mono { color: #F0D9A8; }

.footer-note {
  margin-top: 18px;
  padding-left: 12px;
  border-left: 1px solid rgba(214, 167, 86, .5);
  font-size: 12px;
  line-height: 1.7;
  color: #8A93AC;
}

.footer-legal {
  border-top: 1px solid rgba(216, 211, 200, .16);
}
.footer-legal__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 28px;
  padding-block: 22px;
  font-size: 12px;
  color: #8A93AC;
}
.footer-legal__links {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 20px;
}
.footer-legal__links .footer-link { font-size: 12px; }
.footer-legal__copy { margin: 0; }
.footer-legal__icp { margin: 0 0 0 auto; font-family: var(--font-mono); letter-spacing: 0.04em; }

/* ---------- 19. 显现动效 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity .5s var(--ease), transform .5s var(--ease);
}
[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 20. 响应式：平板 ---------- */
@media (max-width: 1100px) {
  .header-shortcuts { gap: 18px; }
  .site-nav__link { padding: 8px 10px; font-size: 14px; }
  .site-nav__link::after { left: 10px; right: 10px; }
  .split__rail { grid-column: 1 / span 4; }
  .split__stream { grid-column: 5 / span 8; }
  .footer-grid { grid-template-columns: 3fr 2fr 2fr 3fr; }
}

/* ---------- 21. 响应式：移动与折叠导航 ---------- */
@media (max-width: 960px) {
  :root {
    --gutter: 20px;
    --space-6: 40px;
    --space-7: 56px;
    --header-h: 104px;
  }

  .header-utility__inner { min-height: 46px; gap: var(--space-2); }
  .brand-mark__tagline { display: none; }
  .header-shortcuts { display: none; }

  .header-main__inner {
    min-height: 56px;
    gap: var(--space-2);
    justify-content: space-between;
  }
  .header-main__label { display: none; }

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

  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 90;
    display: flex;
    flex-direction: column;
    width: min(86vw, 360px);
    padding: 24px 24px 32px;
    overflow-y: auto;
    background: var(--night);
    border-left: 1px solid rgba(214, 167, 86, .35);
    transform: translateX(100%);
    transition: transform var(--dur) var(--ease);
  }
  .site-nav__top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding-bottom: 18px;
    margin-bottom: 6px;
    border-bottom: 1px solid rgba(216, 211, 200, .16);
  }
  .site-nav__label {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.18em;
    color: var(--gold);
  }
  .site-nav__close {
    padding: 6px 12px;
    border: 1px solid rgba(240, 217, 168, .55);
    font-size: 12px;
    letter-spacing: 0.06em;
    color: var(--gold-mist);
  }

  .site-nav__list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .site-nav__item { border-bottom: 1px solid rgba(216, 211, 200, .14); }
  .site-nav__link {
    display: block;
    padding: 15px 6px;
    font-size: 18px;
    color: #E6E9F2;
  }
  .site-nav__link::after { display: none; }
  .site-nav__link[aria-current="page"] { color: var(--gold-mist); }
  .site-nav__link[aria-current="page"]::before {
    content: "";
    position: absolute;
    left: -12px;
    top: 50%;
    width: 6px;
    height: 6px;
    background: var(--gold);
    transform: translateY(-50%) rotate(45deg);
  }

  .site-nav__foot {
    display: grid;
    gap: 14px;
    margin-top: auto;
    padding-top: 28px;
    border-top: 1px solid rgba(216, 211, 200, .16);
  }
  .site-nav__foot-links {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
  }
  .site-nav__foot-link {
    font-size: 13px;
    color: #A9B2CC;
    text-decoration: none;
  }
  .site-nav__foot-link:hover { color: var(--gold-mist); }

  .site-header[data-open="true"] .site-nav { transform: translateX(0); }
  .site-header[data-open="true"] .nav-backdrop {
    opacity: 1;
    pointer-events: auto;
  }
  .site-header[data-open="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(4.5px) rotate(45deg); }
  .site-header[data-open="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
  .site-header[data-open="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-4.5px) rotate(-45deg); }

  .header-cta { padding: 10px 14px; font-size: 13px; }

  .split { grid-template-columns: 1fr; }
  .split__rail,
  .split__stream { grid-column: 1 / -1; }
  .rail { position: static; top: auto; }

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

  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-4) var(--space-3);
    padding-block: var(--space-5);
  }
  .footer-brand { grid-column: 1 / -1; }
  .footer-contact { grid-column: 1 / -1; }
  .footer-legal__icp { margin-left: 0; }

  .step { padding-bottom: var(--space-3); }
  .band__item { flex: 1 1 50%; border-right: 0; border-bottom: var(--hairline); }
  .band__item:last-child { border-bottom: 0; }
}

/* ---------- 22. 响应式：窄屏 ---------- */
@media (max-width: 620px) {
  body { font-size: 16px; }

  .header-cta { display: none; }
  .header-main__inner { min-height: 54px; }

  .footer-grid { grid-template-columns: 1fr; }
  .footer-brand,
  .footer-contact { grid-column: auto; }

  .footer-legal__inner { gap: 10px 16px; }

  .btn { padding: 11px 18px; }
  .panel { padding: var(--space-3); }
  .tabs__tab { padding: 11px 14px; font-size: 13px; }
  .media-frame__inner { aspect-ratio: 4 / 3; }
}

/* ---------- 23. 动效与可访问性降级 ---------- */
@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;
  }

  .site-nav { transition: none; }
  .site-nav__link::after,
  .header-shortcut::after,
  .footer-link::after { transition: none; }

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

@media (scripting: none) {
  [data-reveal] { opacity: 1; transform: none; }
  .site-nav__close { display: none; }
}