/* =========================================================
   泛亚中心 · 共享站点样式 /assets/site.css
   奶油纸底 + 天山雪青 + 戈壁暖沙 + 点状红橙
   ========================================================= */

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

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

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

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

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

button { font: inherit; color: inherit; }

/* ---------- 2. 变量 ---------- */
:root {
  --paper: #F6F1E7;
  --paper-deep: #F0E8D8;
  --ink: #2A2520;
  --cyan: #7FA6AC;
  --cyan-soft: #D6E3E4;
  --cyan-deep: #4A7076;
  --sand: #DCC49B;
  --sand-soft: #F0E4CC;
  --flame: #C05A2E;
  --tech: #2E6C8E;
  --muted: #6B635A;

  --line: rgba(42, 37, 32, 0.14);
  --line-strong: rgba(42, 37, 32, 0.3);

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

  --rail-w: 248px;
  --content-max: 1080px;
  --gutter: clamp(18px, 4vw, 44px);

  --fs-hero: clamp(34px, 5.2vw, 56px);
  --fs-h2: clamp(26px, 3.4vw, 40px);
  --fs-h3: clamp(20px, 2.2vw, 24px);
  --radius: 3px;
}

/* ---------- 3. 基础排版 ---------- */
body {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.85;
  letter-spacing: 0.002em;
  -webkit-font-smoothing: antialiased;
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 5;
  pointer-events: none;
  opacity: 0.035;
  background-image: radial-gradient(var(--ink) 0.5px, transparent 0.6px);
  background-size: 3px 3px;
}

h1, h2, h3, h4, h5 {
  font-family: var(--font-sans);
  font-weight: 900;
  line-height: 1.24;
  letter-spacing: -0.02em;
  color: var(--ink);
}

h1 { font-size: var(--fs-hero); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); font-weight: 800; letter-spacing: -0.01em; }
h4 { font-size: 20px; font-weight: 800; letter-spacing: -0.005em; }

p { max-width: 70ch; }

a {
  color: var(--cyan-deep);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover { color: var(--flame); }

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

main { display: block; }

#main-content { scroll-margin-top: 96px; }

/* ---------- 4. 跳至主要内容 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 999;
  padding: 10px 18px;
  background: var(--ink);
  color: var(--paper);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  border-radius: var(--radius);
  transform: translateY(-180%);
  transition: transform 0.2s ease;
}

.skip-link:focus {
  transform: translateY(0);
  color: var(--paper);
}

/* ---------- 5. 容器与网格 ---------- */
.content {
  width: 100%;
  max-width: var(--content-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  column-gap: clamp(16px, 2.4vw, 32px);
  row-gap: clamp(24px, 3vw, 40px);
}

.col-main { grid-column: 1 / span 7; }
.col-aside { grid-column: 9 / span 4; }
.col-wide { grid-column: 1 / -1; }
.col-half { grid-column: span 6; }
.col-third { grid-column: span 4; }

/* ---------- 6. 区块与抬头 ---------- */
.section {
  position: relative;
  padding-block: clamp(48px, 7vw, 92px);
}

.section--sand { background: var(--sand-soft); }
.section--cyan { background: var(--cyan-soft); }

.section--ink {
  background: var(--ink);
  color: #EDE4D4;
}

.section--ink h2,
.section--ink h3 { color: #F6F1E7; }

.section--ink .note,
.section--ink .section-head__note { color: rgba(246, 241, 231, 0.72); }

.section--ink .label { color: var(--cyan); }

.label {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 14px;
  letter-spacing: 0.22em;
  color: var(--cyan-deep);
}

.label::before {
  content: "";
  display: inline-block;
  width: 26px;
  height: 1px;
  background: var(--flame);
}

.section-head {
  display: grid;
  grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
  gap: clamp(14px, 3vw, 40px);
  align-items: end;
  margin-bottom: clamp(24px, 3.4vw, 44px);
}

.section-head__title {
  margin-top: 8px;
  font-size: var(--fs-h2);
}

.section-head__note {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

.note {
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
  font-weight: 300;
}

/* ---------- 7. 正文区 ---------- */
.prose { max-width: 66ch; }

.prose p { margin-bottom: 1.2em; }

.prose p:last-child { margin-bottom: 0; }

.prose ul,
.prose ol {
  margin-bottom: 1.2em;
  padding-left: 1.3em;
  list-style: disc;
}

.prose ol { list-style: decimal; }

.prose li { margin-bottom: 0.4em; }

.prose a {
  color: var(--cyan-deep);
  text-decoration-color: var(--cyan);
}

.prose a:hover {
  color: var(--flame);
  text-decoration-color: var(--flame);
}

.prose strong { font-weight: 800; }

/* ---------- 8. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  padding: 12px 20px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-size: 15px;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: 0.01em;
  text-decoration: none;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.btn:hover { text-decoration: none; }

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

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

.btn--cyan {
  background: var(--cyan-soft);
  border-color: var(--cyan);
  color: var(--cyan-deep);
}

.btn--cyan:hover {
  background: var(--cyan);
  color: #FFFFFF;
}

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

.btn--ghost:hover {
  background: var(--sand-soft);
  border-color: var(--flame);
  color: var(--ink);
}

/* ---------- 9. 面包屑 ---------- */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
}

.breadcrumbs__item { color: inherit; }

.breadcrumbs__item a {
  color: var(--cyan-deep);
  text-decoration: none;
}

.breadcrumbs__item a:hover {
  color: var(--flame);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.breadcrumbs__sep {
  color: var(--cyan);
  font-family: var(--font-num);
  font-size: 12px;
}

/* ---------- 10. 框景 ---------- */
.frame {
  position: relative;
  padding: clamp(24px, 4.4vw, 56px);
  border: 1px solid var(--line);
  background:
    linear-gradient(180deg, rgba(240, 228, 204, 0.55) 0%, rgba(246, 241, 231, 0) 62%),
    var(--paper);
}

.frame::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  right: 0;
  height: 8px;
  pointer-events: none;
  background-image: repeating-linear-gradient(90deg, rgba(74, 112, 118, 0.55) 0 1px, transparent 1px 16px);
}

.frame::after {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: -1px;
  width: 8px;
  pointer-events: none;
  background-image: repeating-linear-gradient(180deg, rgba(74, 112, 118, 0.32) 0 1px, transparent 1px 16px);
}

/* ---------- 11. 图形与图注容器 ---------- */
.media {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background-color: var(--cyan-soft);
  background-image:
    linear-gradient(115deg, rgba(127, 166, 172, 0.4) 0%, rgba(240, 228, 204, 0.55) 100%),
    repeating-linear-gradient(90deg, rgba(74, 112, 118, 0.14) 0 1px, transparent 1px 28px);
}

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

.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--square { aspect-ratio: 1 / 1; }

.media--sand {
  background-color: var(--sand-soft);
  background-image:
    linear-gradient(115deg, rgba(220, 196, 155, 0.6) 0%, rgba(246, 241, 231, 0.75) 100%),
    repeating-linear-gradient(90deg, rgba(192, 90, 46, 0.12) 0 1px, transparent 1px 28px);
}

.media--deep {
  background-color: var(--cyan-deep);
  background-image:
    linear-gradient(115deg, rgba(46, 108, 142, 0.55) 0%, rgba(74, 112, 118, 0.95) 100%),
    repeating-linear-gradient(90deg, rgba(246, 241, 231, 0.16) 0 1px, transparent 1px 28px);
}

.figure { margin: 0; }

.figure__caption {
  margin-top: 10px;
  padding-left: 10px;
  border-left: 2px solid var(--cyan);
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  font-weight: 300;
}

/* ---------- 12. 说明块与标签 ---------- */
.callout {
  padding: clamp(16px, 2.4vw, 26px);
  background: var(--sand-soft);
  border-left: 3px solid var(--sand);
}

.callout--cyan {
  background: var(--cyan-soft);
  border-left-color: var(--cyan-deep);
}

.callout__title {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 14px;
  letter-spacing: 0.16em;
  color: var(--cyan-deep);
}

.callout p {
  font-size: 15px;
  line-height: 1.8;
}

.tag {
  display: inline-block;
  padding: 2px 8px;
  border: 1px solid var(--cyan);
  border-radius: 2px;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: 0.12em;
  line-height: 1.6;
  color: var(--cyan-deep);
}

/* ---------- 13. 章节目录 ---------- */
.toc {
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.toc__list {
  display: grid;
  gap: 2px;
}

.toc__link {
  display: block;
  padding: 6px 8px 6px 14px;
  border-left: 2px solid transparent;
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.18s ease, background-color 0.18s ease, border-color 0.18s ease;
}

.toc__link:hover {
  color: var(--cyan-deep);
  background: var(--cyan-soft);
}

.toc__link[data-active="true"] {
  color: var(--ink);
  font-weight: 700;
  border-left-color: var(--flame);
  background: var(--sand-soft);
}

/* ---------- 14. 页头：侧边轨道 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 60;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
  transition: box-shadow 0.2s ease;
}

.site-header[data-scrolled="true"] {
  box-shadow: 0 6px 18px rgba(42, 37, 32, 0.08);
}

.rail {
  display: flex;
  flex-direction: column;
  width: 100%;
}

.rail__top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  width: 100%;
  padding: 12px var(--gutter);
}

.brand-lockup {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 8px;
  text-decoration: none;
  color: inherit;
}

.brand-lockup:hover { color: inherit; }

.brand-lockup__name {
  font-size: 19px;
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.3;
}

.brand-lockup__edition {
  padding: 2px 6px;
  border: 1px solid var(--cyan);
  border-radius: 2px;
  font-family: var(--font-num);
  font-size: 11px;
  letter-spacing: 0.12em;
  line-height: 1.5;
  color: var(--cyan-deep);
  white-space: nowrap;
}

.brand-lockup__status {
  flex-basis: 100%;
  font-size: 12px;
  line-height: 1.5;
  color: var(--muted);
  font-weight: 300;
}

.rail-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: transparent;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink);
  cursor: pointer;
}

.js-ready .rail-toggle { display: inline-flex; }

.rail-toggle:hover { background: var(--sand-soft); }

.rail-toggle__bars {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 18px;
}

.rail-toggle__bars span {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: currentColor;
  transition: transform 0.22s ease;
}

.site-header[data-open="true"] .rail-toggle__bars span:first-child {
  transform: translateY(3px) rotate(45deg);
}

.site-header[data-open="true"] .rail-toggle__bars span:last-child {
  transform: translateY(-3px) rotate(-45deg);
}

.rail-toggle__label { white-space: nowrap; }

.rail__panel {
  display: block;
  padding: 0 var(--gutter) 18px;
}

.rail__panel[hidden] { display: none; }

.js-ready .rail__panel {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  padding: 8px var(--gutter) 20px;
  max-height: calc(100vh - 76px);
  overflow-y: auto;
  background: var(--paper);
  border-bottom: 1px solid var(--line);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity 0.22s ease, transform 0.22s ease, visibility 0.22s;
}

.js-ready .site-header[data-open="true"] .rail__panel {
  opacity: 1;
  visibility: visible;
  transform: none;
}

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

.rail-nav__link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 9px 10px 9px 12px;
  border-left: 2px solid transparent;
  font-size: 16px;
  line-height: 1.5;
  color: var(--ink);
  text-decoration: none;
  transition: background-color 0.18s ease, color 0.18s ease, border-color 0.18s ease;
}

.rail-nav__link:hover {
  background: var(--cyan-soft);
  color: var(--cyan-deep);
}

.rail-nav__index {
  min-width: 1.8em;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan-deep);
}

.rail-nav__label { flex: 1 1 auto; }

.rail-nav__link[aria-current="page"] {
  background: var(--sand-soft);
  border-left-color: var(--flame);
  font-weight: 700;
  color: var(--ink);
}

.rail-nav__link[aria-current="page"] .rail-nav__index { color: var(--flame); }

.rail-nav__link[aria-current="page"]::after {
  content: "";
  flex: 0 0 auto;
  width: 6px;
  height: 6px;
  background: var(--flame);
}

.rail-foot {
  margin-top: 18px;
  padding-top: 16px;
  border-top: 1px dotted var(--line-strong);
}

.rail-foot__save {
  margin-bottom: 12px;
  max-width: none;
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  font-weight: 300;
}

.rail-foot__home {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding-bottom: 2px;
  border-bottom: 1px solid var(--cyan);
  font-size: 14px;
  font-weight: 700;
  color: var(--cyan-deep);
  text-decoration: none;
}

.rail-foot__home:hover {
  color: var(--flame);
  border-bottom-color: var(--flame);
}

/* ---------- 15. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 104px);
  background: var(--ink);
  color: #E9E1D2;
}

.site-footer::before {
  content: "";
  display: block;
  height: 10px;
  background-image: repeating-linear-gradient(90deg, rgba(214, 227, 228, 0.4) 0 1px, transparent 1px 14px);
}

.site-footer p { max-width: none; }

.site-footer a {
  color: #E9E1D2;
  text-decoration: none;
}

.site-footer a:hover {
  color: var(--sand);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.footer-inner {
  padding-block: clamp(36px, 5.6vw, 68px) clamp(22px, 3vw, 34px);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1.25fr;
  gap: clamp(24px, 4vw, 48px);
}

.footer-brand {
  margin-bottom: 10px;
  font-size: clamp(22px, 3vw, 28px);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: #F6F1E7;
}

.footer-brand__note {
  margin-bottom: 10px;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(233, 225, 210, 0.82);
  font-weight: 300;
}

.footer-brand__meta {
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.footer-heading {
  margin-bottom: 14px;
  font-family: var(--font-serif);
  font-weight: 500;
  font-size: 13px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.footer-links {
  display: grid;
  gap: 8px;
  font-size: 15px;
  line-height: 1.6;
}

.footer-contact {
  display: grid;
  gap: 10px;
  font-size: 14px;
  line-height: 1.65;
}

.footer-contact__label {
  display: block;
  margin-bottom: 2px;
  font-family: var(--font-num);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.footer-contact__value {
  display: block;
  color: #E9E1D2;
  word-break: break-word;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px 24px;
  margin-top: clamp(28px, 4vw, 44px);
  padding-top: 18px;
  border-top: 1px solid rgba(233, 225, 210, 0.18);
  font-size: 13px;
  line-height: 1.7;
  color: rgba(233, 225, 210, 0.7);
}

.footer-legal__note { color: rgba(233, 225, 210, 0.55); }

/* ---------- 16. 返回顶部 ---------- */
.back-to-top {
  --p: 0deg;
  position: fixed;
  right: clamp(14px, 3vw, 32px);
  bottom: clamp(14px, 3vw, 32px);
  z-index: 80;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border: 0;
  border-radius: 50%;
  background: var(--paper);
  color: var(--ink);
  cursor: pointer;
  box-shadow: 0 0 0 1px var(--line), 0 4px 14px rgba(42, 37, 32, 0.12);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity 0.24s ease, transform 0.24s ease, visibility 0.24s, background-color 0.18s ease;
}

.back-to-top[data-visible="true"] {
  opacity: 1;
  visibility: visible;
  transform: none;
}

.back-to-top:hover { background: var(--sand-soft); }

.back-to-top::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 50%;
  pointer-events: none;
  background: conic-gradient(from -90deg, var(--flame) 0 var(--p), rgba(42, 37, 32, 0.12) var(--p) 360deg);
  -webkit-mask: radial-gradient(farthest-side, transparent calc(100% - 3px), #000 calc(100% - 3px));
  mask: radial-gradient(farthest-side, transparent calc(100% - 3px), #000 calc(100% - 3px));
}

.back-to-top__icon {
  position: relative;
  z-index: 1;
  font-size: 15px;
  line-height: 1;
}

/* ---------- 17. 显现 ---------- */
.js-ready [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.4s ease, transform 0.4s ease;
}

.js-ready [data-reveal][data-revealed="true"] {
  opacity: 1;
  transform: none;
}

/* ---------- 18. 工具类 ---------- */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* ---------- 19. 断点 ---------- */
@media (max-width: 900px) {
  .col-main,
  .col-aside,
  .col-wide,
  .col-half,
  .col-third { grid-column: 1 / -1; }

  .section-head {
    grid-template-columns: minmax(0, 1fr);
    align-items: start;
  }

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

@media (max-width: 600px) {
  body { font-size: 16px; }

  .brand-lockup__name { font-size: 17px; }

  .brand-lockup__status { font-size: 11px; }

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

  .footer-legal { flex-direction: column; align-items: flex-start; }
}

@media (min-width: 1024px) {
  body { padding-left: var(--rail-w); }

  #main-content { scroll-margin-top: 24px; }

  .site-header {
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    width: var(--rail-w);
    overflow-y: auto;
    border-bottom: 0;
    border-right: 1px solid var(--line);
    background: linear-gradient(180deg, #F2ECDF 0%, var(--paper) 46%);
  }

  .site-header[data-scrolled="true"] {
    box-shadow: 4px 0 16px rgba(42, 37, 32, 0.06);
  }

  .site-header::after {
    content: "";
    position: absolute;
    top: 0;
    bottom: 0;
    right: -1px;
    width: 7px;
    pointer-events: none;
    background-image: repeating-linear-gradient(180deg, rgba(74, 112, 118, 0.32) 0 1px, transparent 1px 18px);
  }

  .rail {
    min-height: 100%;
    padding: 28px 22px 24px;
  }

  .rail__top {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
    padding: 0 0 18px;
    border-bottom: 1px solid var(--line);
  }

  .brand-lockup__name { font-size: 23px; }

  .brand-lockup__status { font-size: 12.5px; }

  .rail-toggle { display: none !important; }

  .site-header .rail__panel,
  .js-ready .site-header .rail__panel,
  .js-ready .site-header[data-open="true"] .rail__panel {
    position: static;
    display: flex;
    flex: 1 1 auto;
    flex-direction: column;
    max-height: none;
    overflow: visible;
    padding: 18px 0 0;
    background: transparent;
    border: 0;
    opacity: 1;
    visibility: visible;
    transform: none;
    transition: none;
  }

  .rail-nav__link { font-size: 15.5px; }

  .rail-foot { margin-top: auto; }

  .back-to-top { right: 32px; bottom: 32px; }
}

/* ---------- 20. 降低动效 ---------- */
@media (prefers-reduced-motion: no-preference) {
  html { scroll-behavior: smooth; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }

  .js-ready [data-reveal] {
    opacity: 1;
    transform: none;
  }

  .back-to-top {
    transform: none;
  }
}