/* =========================================================
   6686主页 · 共享样式 /assets/site.css
   01 重置 · 02 变量 · 03 基础排版 · 04 布局工具
   05 基础组件 · 06 框架式头部 · 07 页脚 · 08 正文容器
   ========================================================= */

/* ---------- 01 重置 ---------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-padding-top: 88px;
}

body, h1, h2, h3, h4, h5, p, ul, ol, li, figure, blockquote, dl, dd { margin: 0; }
ul, ol { padding: 0; list-style: none; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
img, svg, video { display: block; max-width: 100%; height: auto; }
table { border-collapse: collapse; }

/* ---------- 02 变量 ---------- */
:root {
  --ink-900: #07131F;
  --ink-800: #0B1D2E;
  --panel: #123047;
  --line: #1B405C;
  --cyan: #24E0CE;
  --cyan-soft: #A5FFF5;
  --amber: #FFB84D;
  --amber-soft: #FFE0AE;
  --paper: #F3F7FA;
  --text: #EDF6FB;
  --muted: #9AB0C4;

  --radius-lg: 28px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --pill: 999px;

  --rail: 264px;
  --content-max: 1200px;

  --font-display: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-note: "Songti SC", "Noto Serif SC", "Source Han Serif SC", Georgia, "Microsoft YaHei", serif;
  --font-mono: ui-monospace, "SFMono-Regular", Menlo, Consolas, "Liberation Mono", monospace;

  --ease: cubic-bezier(.2, .7, .3, 1);
}

/* ---------- 03 基础排版 ---------- */
body {
  min-height: 100vh;
  background-color: var(--ink-800);
  background-image:
    linear-gradient(rgba(27, 64, 92, .22) 1px, transparent 1px),
    linear-gradient(90deg, rgba(27, 64, 92, .22) 1px, transparent 1px);
  background-size: 120px 120px;
  background-position: -1px -1px;
  color: var(--text);
  font-family: var(--font-body);
  font-size: clamp(16px, .35vw + 14.6px, 17px);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  color: var(--text);
  text-wrap: balance;
}

h1 { font-size: clamp(38px, 5.4vw, 72px); line-height: 1.06; font-weight: 900; letter-spacing: -.02em; }
h2 { font-size: clamp(26px, 3.2vw, 40px); line-height: 1.16; font-weight: 900; letter-spacing: -.012em; }
h3 { font-size: clamp(19px, 1.8vw, 24px); line-height: 1.32; font-weight: 800; letter-spacing: -.006em; }
h4 { font-size: clamp(16px, 1.4vw, 18px); line-height: 1.4; font-weight: 800; }

p { max-width: 68ch; }
strong, b { font-weight: 800; color: var(--cyan-soft); }

::selection { background: var(--cyan); color: #04211E; }

:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 6px;
}

/* ---------- 04 布局工具 ---------- */
.wrap {
  width: 100%;
  max-width: var(--content-max);
  margin-inline: auto;
  padding-inline: clamp(18px, 4vw, 44px);
}

.page-main { display: block; padding-block: clamp(24px, 3.6vw, 52px) clamp(48px, 7vw, 92px); }

.grid { display: grid; gap: clamp(14px, 1.8vw, 22px); }
.grid-2 { display: grid; gap: clamp(14px, 1.8vw, 22px); grid-template-columns: 1fr; }
.grid-3 { display: grid; gap: clamp(14px, 1.8vw, 22px); grid-template-columns: 1fr; }
.grid-12 { display: grid; gap: clamp(14px, 1.8vw, 22px); grid-template-columns: repeat(12, minmax(0, 1fr)); }

.col-3, .col-4, .col-5, .col-6, .col-7, .col-8, .col-12 { grid-column: span 12; }

@media (min-width: 700px) {
  .grid-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-3 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
}

@media (min-width: 900px) {
  .col-3 { grid-column: span 3; }
  .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; }
}

/* ---------- 05 基础组件 ---------- */
/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 22px;
  border: 1px solid transparent;
  border-radius: var(--pill);
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .02em;
  white-space: nowrap;
  transition: background-color .18s var(--ease), border-color .18s var(--ease), color .18s var(--ease);
}

.btn-primary { background: var(--cyan); border-color: var(--cyan); color: #04211E; }
.btn-primary:hover, .btn-primary:focus-visible { background: var(--cyan-soft); border-color: var(--cyan-soft); color: #04211E; }

.btn-amber { background: var(--amber); border-color: var(--amber); color: #241500; }
.btn-amber:hover, .btn-amber:focus-visible { background: var(--amber-soft); border-color: var(--amber-soft); color: #241500; }

.btn-ghost { background: transparent; border-color: var(--line); color: var(--text); }
.btn-ghost:hover, .btn-ghost:focus-visible { border-color: var(--cyan); color: var(--cyan-soft); }

.btn-sm { min-height: 38px; padding: 0 16px; font-size: 13px; }

/* 标签与编号 */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 12px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  background: rgba(18, 48, 71, .6);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  line-height: 1.6;
}
.tag--cyan { border-color: rgba(36, 224, 206, .45); color: var(--cyan); }
.tag--amber { border-color: rgba(255, 184, 77, .45); color: var(--amber); }

.entry-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--cyan);
}
.entry-badge::before {
  content: "";
  width: 11px;
  height: 11px;
  border-radius: 50%;
  border: 1px solid var(--cyan);
  box-shadow: inset 0 0 0 2px var(--ink-800);
  flex: none;
}

.entry-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--cyan);
  transition: color .18s var(--ease);
}

/* 批注与文本辅助 */
.note {
  font-family: var(--font-note);
  font-size: 13px;
  line-height: 1.8;
  color: var(--amber-soft);
  letter-spacing: .01em;
}

.anno {
  text-decoration: underline;
  text-decoration-color: var(--amber);
  text-decoration-thickness: 2px;
  text-underline-offset: 5px;
}

.lede {
  font-size: clamp(16px, 1.2vw, 19px);
  line-height: 1.8;
  color: #C6D8E6;
}

.vertical-note {
  writing-mode: vertical-rl;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .38em;
  color: var(--muted);
  text-transform: uppercase;
}

.eyebrow {
  display: block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .26em;
  text-transform: uppercase;
  color: var(--cyan);
}

/* 卡片 */
.card {
  position: relative;
  padding: clamp(18px, 2.4vw, 26px);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--panel);
  transition: border-color .18s var(--ease), background-color .18s var(--ease);
}
.card-lg { border-radius: var(--radius-lg); }
.card-paper { background: var(--paper); border-color: #C9D8E4; color: #0B1D2E; }
.card-paper h2, .card-paper h3, .card-paper h4 { color: #0B1D2E; }
.card-paper .lede, .card-paper p { color: #29465C; }

.card--link:hover, .card--link:focus-within { border-color: var(--cyan); background: #143551; }
.card--link:hover .entry-num, .card--link:focus-within .entry-num { color: var(--cyan-soft); }

/* 章节头 */
.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: clamp(16px, 2.4vw, 26px);
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}
.section-title { font-size: clamp(22px, 2.6vw, 32px); font-weight: 900; letter-spacing: -.01em; }

/* 图片容器（页面阶段放置图片或线框占位） */
.media {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--ink-900);
}
.media--lg { border-radius: var(--radius-lg); }
.media > img, .media > svg { width: 100%; height: 100%; object-fit: cover; }
.ratio-16-9 { aspect-ratio: 16 / 9; }
.ratio-4-3 { aspect-ratio: 4 / 3; }
.ratio-3-2 { aspect-ratio: 3 / 2; }
.ratio-1-1 { aspect-ratio: 1 / 1; }
.media-caption {
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--muted);
}

/* 表格 */
.table-scroll { width: 100%; overflow-x: auto; border-radius: var(--radius-md); border: 1px solid var(--line); }
.data-table { width: 100%; min-width: 520px; font-size: 15px; }
.data-table th, .data-table td { padding: 12px 14px; text-align: left; border-bottom: 1px solid var(--line); }
.data-table tr:last-child td { border-bottom: 0; }
.data-table th {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .14em;
  color: var(--cyan);
  background: rgba(18, 48, 71, .8);
}

/* 侧栏索引 */
.index-link {
  display: block;
  padding: 8px 12px;
  border-left: 2px solid var(--line);
  color: var(--muted);
  font-size: 14px;
  transition: color .18s var(--ease), border-color .18s var(--ease), background-color .18s var(--ease);
}
.index-link:hover { color: var(--cyan-soft); border-left-color: var(--cyan); }
.index-link.is-active {
  color: var(--cyan);
  border-left-color: var(--cyan);
  background: rgba(36, 224, 206, .08);
}

/* 面包屑 */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--muted);
}
.breadcrumb a { color: var(--muted); border-bottom: 1px solid transparent; transition: color .18s var(--ease), border-color .18s var(--ease); }
.breadcrumb a:hover { color: var(--cyan-soft); border-bottom-color: var(--cyan); }
.breadcrumb-sep { color: var(--line); }
.breadcrumb [aria-current="page"] { color: var(--cyan); }

/* 页面题头 */
.page-head {
  display: grid;
  gap: 14px;
  padding-bottom: clamp(20px, 3vw, 32px);
  margin-bottom: clamp(24px, 3.4vw, 40px);
  border-bottom: 1px solid var(--line);
}

/* ---------- 06 框架式头部 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  padding: 10px 18px;
  border-radius: var(--pill);
  background: var(--cyan);
  color: #04211E;
  font-size: 14px;
  font-weight: 700;
  transform: translateY(-160%);
  transition: transform .18s var(--ease);
}
.skip-link:focus-visible { transform: translateY(0); outline-offset: 3px; }

.site-frame {
  position: sticky;
  top: 0;
  z-index: 90;
  background: var(--ink-900);
  border-bottom: 1px solid var(--line);
}

.frame-rail {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 11px 18px;
  background: var(--ink-900);
}

.rail-brand { display: flex; align-items: center; gap: 10px; min-width: 0; }

.rail-mark {
  flex: none;
  padding: 3px 8px;
  border-radius: 7px;
  background: var(--cyan);
  color: #04211E;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .14em;
  line-height: 1.7;
}

.rail-title {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 900;
  letter-spacing: .01em;
  color: var(--text);
  white-space: nowrap;
}
.rail-title:hover { color: var(--cyan-soft); }

.rail-tag {
  display: none;
  font-family: var(--font-note);
  font-size: 12px;
  color: var(--amber-soft);
  letter-spacing: .02em;
}

/* 移动目录按钮 */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  min-height: 40px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  transition: border-color .18s var(--ease), color .18s var(--ease);
}
.nav-toggle:hover { border-color: var(--cyan); color: var(--cyan-soft); }

.nav-toggle-bars { position: relative; width: 16px; height: 2px; background: currentColor; border-radius: 2px; }
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 16px;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform .18s var(--ease);
}
.nav-toggle-bars::before { top: -5px; }
.nav-toggle-bars::after { top: 5px; }

.site-frame[data-open] .nav-toggle { border-color: var(--cyan); color: var(--cyan-soft); }
.site-frame[data-open] .nav-toggle-bars { background: transparent; }
.site-frame[data-open] .nav-toggle-bars::before { transform: translateY(5px) rotate(45deg); }
.site-frame[data-open] .nav-toggle-bars::after { transform: translateY(-5px) rotate(-45deg); }

/* 移动下拉面板 */
.rail-panel {
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  display: none;
  flex-direction: column;
  gap: 18px;
  padding: 18px 18px 22px;
  max-height: calc(100dvh - 64px);
  overflow-y: auto;
  overscroll-behavior: contain;
  background: var(--ink-900);
  border-bottom: 1px solid var(--line);
  box-shadow: 0 28px 60px rgba(0, 0, 0, .5);
}
.site-frame[data-open] .rail-panel { display: flex; }

.rail-nav { display: flex; flex-direction: column; gap: 10px; min-width: 0; }

.rail-nav-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .26em;
  color: #4C7796;
  text-transform: uppercase;
}

.rail-nav-list { display: flex; flex-direction: column; gap: 2px; }

.rail-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: 1px solid transparent;
  border-radius: 14px;
  color: var(--text);
  font-size: 15px;
  transition: border-color .18s var(--ease), background-color .18s var(--ease), color .18s var(--ease);
}
.rail-link:hover, .rail-link:focus-visible {
  border-color: var(--cyan);
  background: rgba(36, 224, 206, .08);
  color: var(--cyan-soft);
}
.rail-num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--cyan);
}
.rail-label { min-width: 0; }

.rail-link[aria-current="page"] {
  border-color: var(--cyan);
  background: rgba(36, 224, 206, .14);
  box-shadow: inset 3px 0 0 var(--cyan);
  color: var(--cyan-soft);
  font-weight: 700;
}
.rail-link[aria-current="page"] .rail-num { color: var(--amber); }

.rail-foot { display: flex; flex-direction: column; gap: 12px; }
.rail-cta { width: 100%; }

.rail-status {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--muted);
  line-height: 1.6;
}
.status-dot {
  flex: none;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 3px rgba(36, 224, 206, .16);
}

.rail-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .1em;
  color: var(--muted);
}
.rail-legend-item { display: inline-flex; align-items: center; gap: 6px; }
.legend-dot { flex: none; width: 9px; height: 9px; border-radius: 50%; }
.legend-dot--cyan { background: var(--cyan); }
.legend-dot--amber { background: var(--amber); }

.rail-edge { display: none; }

/* 阅读进度 */
.rail-progress {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  z-index: 95;
  background: rgba(27, 64, 92, .55);
  pointer-events: none;
}
.rail-progress-bar {
  display: block;
  width: 100%;
  height: 100%;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform .12s linear;
}

/* 桌面端：导航成为页面左边框 */
@media (min-width: 1024px) {
  html { scroll-padding-top: 24px; }
  body { padding-left: var(--rail); }

  .site-frame {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: var(--rail);
    border-bottom: 0;
    border-right: 1px solid var(--line);
    background: var(--ink-900);
    z-index: 90;
  }

  .frame-rail {
    height: 100%;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 26px;
    padding: 28px 30px 24px 22px;
    overflow-y: auto;
  }

  .rail-brand { flex-wrap: wrap; gap: 8px 10px; }
  .rail-title { font-size: 21px; }
  .rail-tag { display: block; width: 100%; }
  .nav-toggle { display: none; }

  .rail-panel {
    position: static;
    display: flex;
    flex: 1 1 auto;
    max-height: none;
    overflow: visible;
    padding: 0;
    border: 0;
    box-shadow: none;
    background: transparent;
  }

  .rail-nav { flex: 1 1 auto; gap: 12px; }
  .rail-foot { margin-top: auto; }
  .rail-cta { width: auto; }

  .rail-edge {
    display: block;
    position: absolute;
    top: 0;
    right: 2px;
    padding: 30px 6px;
    writing-mode: vertical-rl;
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: .38em;
    color: #2A5372;
    pointer-events: none;
  }

  .rail-progress { right: auto; width: var(--rail); height: 4px; }
}

/* ---------- 07 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--ink-900);
  border-top: 1px solid var(--line);
  color: var(--text);
}

.footer-inner { padding-block: clamp(36px, 5vw, 62px) 26px; }

.footer-top {
  display: grid;
  gap: clamp(26px, 4vw, 48px);
  grid-template-columns: minmax(0, 1fr);
}

.footer-brand { display: flex; flex-direction: column; align-items: flex-start; gap: 10px; max-width: 330px; }

.footer-mark {
  padding: 3px 11px;
  border: 1px solid var(--line);
  border-radius: var(--pill);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .2em;
  line-height: 1.8;
}

.footer-name {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 900;
  letter-spacing: .01em;
  color: var(--text);
}

.footer-line {
  font-family: var(--font-note);
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
  max-width: 30ch;
}

.footer-cta { margin-top: 4px; }

.footer-cols {
  display: grid;
  gap: clamp(22px, 3vw, 36px);
  grid-template-columns: minmax(0, 1fr);
}

.footer-col-title {
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--cyan);
  text-transform: uppercase;
}

.footer-links { display: flex; flex-direction: column; gap: 9px; }

.footer-link {
  display: inline-block;
  width: fit-content;
  padding-bottom: 2px;
  color: #C6D8E6;
  font-size: 15px;
  background-image: linear-gradient(var(--cyan), var(--cyan));
  background-repeat: no-repeat;
  background-position: 0 100%;
  background-size: 0% 1px;
  transition: background-size .2s var(--ease), color .2s var(--ease);
}
.footer-link:hover, .footer-link:focus-visible {
  color: var(--cyan-soft);
  background-size: 100% 1px;
}

.footer-contact { display: flex; flex-direction: column; gap: 10px; }
.footer-contact-item { display: flex; flex-direction: column; gap: 1px; }
.footer-contact-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .18em;
  color: var(--muted);
}
.footer-contact-value { color: var(--text); font-size: 14px; line-height: 1.6; overflow-wrap: anywhere; }

.footer-note {
  margin-top: 14px;
  padding-left: 10px;
  border-left: 2px solid rgba(255, 184, 77, .6);
  font-family: var(--font-note);
  font-size: 13px;
  line-height: 1.75;
  color: var(--muted);
}

.footer-path {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 18px;
  margin-top: clamp(26px, 4vw, 42px);
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .12em;
  color: #4C7796;
}
.footer-path-item { display: inline-flex; align-items: center; gap: 8px; }
.footer-path-item::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: currentColor; flex: none; }
.footer-path-item--cyan { color: var(--cyan); }
.footer-path-item--amber { color: var(--amber); }

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 20px;
  margin-top: 20px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}
.footer-legal, .footer-copy {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--muted);
}
.footer-legal-links { display: flex; flex-wrap: wrap; gap: 8px 18px; }
.footer-legal-links .footer-link { font-size: 12px; font-family: var(--font-mono); letter-spacing: .06em; }

@media (min-width: 640px) {
  .footer-cols { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 900px) {
  .footer-top { grid-template-columns: minmax(240px, 320px) minmax(0, 1fr); align-items: start; }
  .footer-cols { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}

/* ---------- 08 正文容器补充 ---------- */
.page-main > .wrap > * + * { margin-top: clamp(20px, 3vw, 34px); }
.page-main a:not(.btn):not(.rail-link):not(.footer-link):not(.index-link) {
  border-bottom: 1px solid rgba(36, 224, 206, .5);
  transition: border-color .18s var(--ease), color .18s var(--ease);
}
.page-main a:not(.btn):not(.rail-link):not(.footer-link):not(.index-link):hover {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan-soft);
}

/* ---------- 09 无障碍与动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
  .rail-progress-bar { transition: none; }
  .skip-link { transition: none; }
}