/* =========================================================
   恒峰平台 · 共享样式表 /assets/site.css
   年鉴式档案骨架：命令栏头部 + 索引页脚 + 通用组件
   ========================================================= */

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

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

body, h1, h2, h3, h4, h5, h6,
p, ul, ol, li, dl, dt, dd,
figure, blockquote, fieldset { margin: 0; padding: 0; }

ul, ol { list-style: none; }

img, svg, video, picture, canvas { display: block; max-width: 100%; }
img { 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; }
table { border-collapse: collapse; width: 100%; }
hr { border: 0; }

/* ---------- 2. 设计令牌 ---------- */
:root {
  --ink-900: #0B0E14;
  --ink-700: #1E2530;
  --indigo-900: #141B33;
  --indigo-600: #2A3A6B;
  --amber-500: #F59E0B;
  --amber-100: #FEF3C7;
  --celadon-600: #2F8F7A;
  --celadon-100: #DDF3EC;
  --paper-50: #F7F5F0;
  --paper-0: #FFFFFF;
  --line-300: #C9C4BA;
  --slate-500: #6B7280;
  --danger-600: #C2412F;

  --font-display: "Barlow Condensed", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  --font-mono: "Roboto Mono", "SFMono-Regular", Consolas, "Liberation Mono", monospace;

  --wrap: 1280px;
  --gutter: 24px;
  --prose: 720px;

  --line: 1px solid var(--line-300);
  --hair-light: 1px solid rgba(247, 245, 240, 0.14);

  --radius: 2px;
  --radius-lg: 4px;

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --dur: 0.28s;

  --shadow-1: 0 1px 2px rgba(11, 14, 20, 0.05), 0 8px 24px -18px rgba(11, 14, 20, 0.35);
  --shadow-2: 0 2px 4px rgba(11, 14, 20, 0.06), 0 20px 48px -28px rgba(11, 14, 20, 0.55);
}

/* ---------- 3. 基础排版 ---------- */
body {
  background: var(--paper-50);
  color: var(--ink-900);
  font-family: var(--font-body);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.14;
  letter-spacing: 0.02em;
  color: var(--ink-900);
  text-wrap: balance;
}

h1 { font-size: clamp(32px, 5vw, 64px); font-weight: 750; }
h2 { font-size: clamp(24px, 3vw, 40px); }
h3 { font-size: clamp(20px, 2vw, 26px); }
h4 { font-size: 18px; font-weight: 650; letter-spacing: 0.03em; }

p { max-width: var(--prose); }
strong { font-weight: 700; }
small { font-size: 12.5px; }

.mono,
.num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.01em;
}

.link {
  color: var(--indigo-600);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
  transition: color var(--dur) var(--ease);
}
.link:hover { color: var(--ink-900); }

::selection { background: var(--amber-500); color: var(--ink-900); }

:focus-visible {
  outline: 2px solid var(--amber-500);
  outline-offset: 2px;
  border-radius: 2px;
}

.skip-link {
  position: fixed;
  left: 16px;
  top: -90px;
  z-index: 400;
  padding: 11px 18px;
  background: var(--amber-500);
  color: var(--ink-900);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  border-radius: var(--radius);
  transition: top 0.2s var(--ease);
}
.skip-link:focus { top: 16px; }

/* ---------- 4. 布局骨架 ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.wrap--wide { max-width: 1440px; }

.prose { max-width: var(--prose); }

.section { padding-block: clamp(56px, 7vw, 112px); }
.section--tight { padding-block: clamp(28px, 4vw, 56px); }

.stack > * + * { margin-top: 16px; }

.grid { display: grid; gap: 24px; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
.grid--split {
  grid-template-columns: minmax(0, 7fr) minmax(0, 3fr);
  align-items: start;
}

/* ---------- 5. 章节头 / 标签 ---------- */
.chapter-head {
  display: flex;
  align-items: center;
  gap: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line-300);
  margin-bottom: 30px;
}
.chapter-no {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--amber-500);
  background: var(--ink-900);
  padding: 3px 9px;
  border-radius: var(--radius);
  line-height: 1.4;
}
.chapter-head h2,
.chapter-head h3 { margin: 0; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--slate-500);
}
.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--amber-500);
  flex: 0 0 auto;
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.05em;
  line-height: 1.7;
  border: 1px solid var(--line-300);
  border-radius: 999px;
  background: var(--paper-0);
  color: var(--slate-500);
  white-space: nowrap;
}
.tag--ok {
  background: var(--celadon-100);
  border-color: rgba(47, 143, 122, 0.32);
  color: #1F6A5A;
}
.tag--warn {
  background: var(--amber-100);
  border-color: rgba(245, 158, 11, 0.36);
  color: #8A5A00;
}
.tag--off {
  background: rgba(194, 65, 47, 0.08);
  border-color: rgba(194, 65, 47, 0.3);
  color: var(--danger-600);
}

/* ---------- 6. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  line-height: 1.25;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  white-space: nowrap;
  transition: background-color var(--dur) var(--ease),
              color var(--dur) var(--ease),
              border-color var(--dur) var(--ease),
              transform var(--dur) var(--ease);
}
.btn--primary { background: var(--amber-500); color: var(--ink-900); }
.btn--primary:hover { background: #FFB224; transform: translateY(-1px); }
.btn--ink { background: var(--ink-900); color: var(--paper-0); }
.btn--ink:hover { background: var(--indigo-900); }
.btn--line { background: var(--paper-0); border-color: var(--line-300); color: var(--ink-900); }
.btn--line:hover { border-color: var(--ink-900); }
.btn--ghost-light { border-color: rgba(247, 245, 240, 0.3); color: var(--paper-0); }
.btn--ghost-light:hover { border-color: var(--amber-500); color: var(--amber-500); }

/* ---------- 7. 面包屑 ---------- */
.breadcrumb {
  padding-block: 20px 0;
  font-size: 12.5px;
  color: var(--slate-500);
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}
.breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line-300);
}
.breadcrumb a:hover {
  color: var(--ink-900);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.breadcrumb [aria-current="page"] {
  color: var(--ink-900);
  font-weight: 600;
}

/* ---------- 8. 响应式图片容器 ---------- */
.frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: linear-gradient(180deg, #EEEBE4 0%, #E2DED5 100%);
  border: 1px solid var(--line-300);
  border-radius: var(--radius);
  aspect-ratio: 16 / 10;
}
.frame > img,
.frame > svg,
.frame > picture,
.frame > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.frame::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid rgba(11, 14, 20, 0.06);
  pointer-events: none;
}
.frame--wide { aspect-ratio: 21 / 9; }
.frame--square { aspect-ratio: 1 / 1; }
.frame--tall { aspect-ratio: 4 / 5; }

/* =========================================================
   9. 站点头部 — 紧凑命令栏
   ========================================================= */
.site-header {
  position: sticky;
  top: 0;
  z-index: 120;
  background: var(--ink-700);
  color: var(--paper-0);
  border-bottom: 1px solid rgba(247, 245, 240, 0.08);
  box-shadow: 0 16px 36px -30px rgba(11, 14, 20, 0.95);
}

.header-inner {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
  min-height: 66px;
  display: flex;
  align-items: center;
  gap: 18px;
}

/* 品牌 */
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-block: 10px;
  flex: 0 0 auto;
}
.brand-mark {
  width: 36px;
  height: 36px;
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  background: var(--indigo-900);
  border: 1px solid rgba(245, 158, 11, 0.45);
  border-radius: var(--radius);
  color: var(--amber-500);
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 800;
  line-height: 1;
}
.brand-text { display: block; }
.brand-name {
  display: block;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 800;
  letter-spacing: 0.06em;
  line-height: 1.15;
  color: #FFFFFF;
}
.brand-tagline {
  display: block;
  margin-top: 1px;
  font-size: 11px;
  letter-spacing: 0.12em;
  line-height: 1.4;
  color: rgba(247, 245, 240, 0.5);
}

/* 数据徽标 */
.data-badge {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 11px;
  flex: 0 0 auto;
  border: 1px solid rgba(247, 245, 240, 0.16);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  line-height: 1.6;
  color: rgba(247, 245, 240, 0.62);
  white-space: nowrap;
}
.data-dot {
  width: 6px;
  height: 6px;
  flex: 0 0 auto;
  border-radius: 50%;
  background: var(--celadon-600);
  box-shadow: 0 0 0 3px rgba(47, 143, 122, 0.2);
}

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  margin-left: auto;
  padding: 9px 13px;
  flex: 0 0 auto;
  border: 1px solid rgba(247, 245, 240, 0.22);
  border-radius: var(--radius);
  color: var(--paper-0);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.08em;
  transition: border-color var(--dur) var(--ease);
}
.nav-toggle:hover { border-color: rgba(245, 158, 11, 0.6); }
.nav-toggle-bars {
  position: relative;
  display: block;
  width: 16px;
  height: 10px;
  flex: 0 0 auto;
}
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 1.5px;
  background: currentColor;
  transition: transform 0.24s var(--ease);
}
.nav-toggle-bars::before { top: 0; }
.nav-toggle-bars::after { bottom: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { transform: translateY(4.25px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { transform: translateY(-4.25px) rotate(-45deg); }

/* 主导航 */
.primary-nav {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 1px;
}
.nav-list > li { display: flex; }

.nav-list a {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 5px;
  padding: 10px 10px 12px;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.02em;
  color: rgba(247, 245, 240, 0.74);
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
.nav-list a:hover {
  color: #FFFFFF;
  background: rgba(247, 245, 240, 0.06);
}
.nav-list a[aria-current="page"] { color: #FFFFFF; }
.nav-list a[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: 10px;
  right: 10px;
  bottom: 5px;
  height: 2px;
  background: var(--amber-500);
}
.nav-index {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0;
  line-height: 1;
  color: var(--amber-500);
  opacity: 0.55;
}
.nav-list a[aria-current="page"] .nav-index { opacity: 1; }

.nav-tail {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: 6px;
  padding-left: 14px;
  border-left: 1px solid rgba(247, 245, 240, 0.14);
}
.nav-link-soft {
  padding: 9px 12px;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.03em;
  white-space: nowrap;
  color: rgba(247, 245, 240, 0.72);
  border: 1px solid rgba(247, 245, 240, 0.16);
  border-radius: var(--radius);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.nav-link-soft:hover {
  color: var(--amber-500);
  border-color: rgba(245, 158, 11, 0.5);
}
.nav-cta {
  display: inline-flex;
  align-items: center;
  padding: 9px 16px;
  white-space: nowrap;
  background: var(--amber-500);
  color: var(--ink-900);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.04em;
  border-radius: var(--radius);
  transition: background-color var(--dur) var(--ease);
}
.nav-cta:hover { background: #FFB224; }

/* =========================================================
   10. 站点页脚 — 年鉴尾部索引
   ========================================================= */
.site-footer {
  position: relative;
  margin-top: clamp(64px, 8vw, 120px);
  background: var(--ink-900);
  color: rgba(247, 245, 240, 0.68);
  font-size: 14.5px;
  line-height: 1.7;
}
.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--indigo-900) 0%, var(--indigo-600) 46%, var(--amber-500) 100%);
}

.footer-inner {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding: clamp(48px, 6vw, 78px) var(--gutter) 0;
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) minmax(0, 1fr) minmax(0, 1.35fr);
  gap: clamp(28px, 4vw, 64px);
  padding-bottom: clamp(36px, 4vw, 56px);
}

.footer-brand-name {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 16px;
  font-family: var(--font-display);
  font-size: 26px;
  font-weight: 800;
  letter-spacing: 0.06em;
  line-height: 1.1;
  color: #FFFFFF;
}
.footer-brand-name::before {
  content: "";
  width: 10px;
  height: 10px;
  flex: 0 0 auto;
  background: var(--amber-500);
  transform: rotate(45deg);
}
.footer-summary {
  max-width: 48ch;
  margin-bottom: 18px;
  color: rgba(247, 245, 240, 0.62);
}
.footer-chip {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 5px 11px;
  border: 1px solid rgba(247, 245, 240, 0.16);
  border-radius: 999px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.05em;
  color: rgba(247, 245, 240, 0.55);
}

.footer-col-title {
  margin-bottom: 16px;
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(247, 245, 240, 0.12);
  font-family: var(--font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--amber-500);
}

.footer-list li + li { margin-top: 10px; }
.footer-list a {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 14.5px;
  color: rgba(247, 245, 240, 0.72);
  transition: color var(--dur) var(--ease);
}
.footer-list a::before {
  content: "";
  width: 5px;
  height: 5px;
  flex: 0 0 auto;
  border: 1px solid rgba(247, 245, 240, 0.35);
  transform: rotate(45deg);
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.footer-list a:hover { color: #FFFFFF; }
.footer-list a:hover::before {
  background: var(--amber-500);
  border-color: var(--amber-500);
}

.footer-contact { display: grid; gap: 16px; }
.footer-contact-row {
  display: grid;
  grid-template-columns: 74px minmax(0, 1fr);
  gap: 12px;
  align-items: baseline;
}
.footer-contact dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(247, 245, 240, 0.42);
}
.footer-contact dd {
  color: rgba(247, 245, 240, 0.85);
  font-size: 14.5px;
  word-break: break-word;
}
.footer-contact-value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 15px;
  letter-spacing: 0.02em;
  color: #FFFFFF;
}
.footer-note {
  max-width: none;
  margin-top: 18px;
  padding-top: 14px;
  border-top: 1px dashed rgba(247, 245, 240, 0.16);
  font-size: 12.5px;
  line-height: 1.7;
  color: rgba(247, 245, 240, 0.45);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 28px;
  padding: 22px 0 42px;
  border-top: 1px solid rgba(247, 245, 240, 0.12);
  font-size: 12.5px;
  color: rgba(247, 245, 240, 0.45);
}
.footer-icp { max-width: none; font-family: var(--font-mono); letter-spacing: 0.03em; }
.footer-copyright { max-width: none; }
.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  margin-left: auto;
}
.footer-legal a {
  color: rgba(247, 245, 240, 0.6);
  transition: color var(--dur) var(--ease);
}
.footer-legal a:hover { color: var(--amber-500); }

/* =========================================================
   11. 阅读进度 / 返回顶部（由 JS 注入）
   ========================================================= */
.read-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: 300;
  background: rgba(11, 14, 20, 0.4);
  pointer-events: none;
}
.read-progress__bar {
  display: block;
  height: 100%;
  width: 0;
  background: var(--amber-500);
  transition: width 0.12s linear;
}

.to-top {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 180;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  background: var(--ink-900);
  color: var(--amber-500);
  border: 1px solid rgba(245, 158, 11, 0.35);
  border-radius: var(--radius);
  box-shadow: var(--shadow-2);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity var(--dur) var(--ease),
              transform var(--dur) var(--ease),
              visibility var(--dur) linear,
              background-color var(--dur) var(--ease);
}
.to-top[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.to-top:hover { background: var(--indigo-900); }

/* =========================================================
   12. 入场动画
   ========================================================= */
html.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.36s var(--ease), transform 0.36s var(--ease);
}
html.js [data-reveal="in"] {
  opacity: 1;
  transform: none;
}

/* =========================================================
   13. 响应式
   ========================================================= */
@media (max-width: 1180px) {
  .data-badge { display: none; }
}

@media (max-width: 1080px) {
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 1023px) {
  .nav-tail .nav-link-soft { display: none; }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--split { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 899px) {
  html { scroll-padding-top: 76px; }

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

  .primary-nav {
    position: absolute;
    left: 0;
    right: 0;
    top: 100%;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin: 0;
    padding: 10px var(--gutter) 24px;
    background: var(--ink-900);
    border-top: 1px solid rgba(247, 245, 240, 0.1);
    border-bottom: 3px solid var(--amber-500);
    box-shadow: 0 30px 52px -32px rgba(11, 14, 20, 0.95);
    max-height: 78vh;
    overflow-y: auto;
  }
  .primary-nav[data-open] { display: flex; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .nav-list a {
    padding: 14px 0 14px 13px;
    font-size: 15px;
    border-bottom: 1px solid rgba(247, 245, 240, 0.08);
  }
  .nav-list a[aria-current="page"] { color: var(--amber-500); }
  .nav-list a[aria-current="page"]::after {
    left: 0;
    right: auto;
    top: 50%;
    bottom: auto;
    width: 3px;
    height: 18px;
    transform: translateY(-50%);
  }
  .nav-list a[aria-current="page"] .nav-index { color: var(--amber-500); }

  .nav-tail {
    flex-direction: column;
    align-items: stretch;
    gap: 10px;
    margin: 20px 0 0;
    padding: 0;
    border-left: 0;
  }
  .nav-tail .nav-link-soft {
    display: block;
    padding: 12px;
    text-align: center;
    font-size: 14px;
  }
  .nav-cta {
    justify-content: center;
    padding: 13px;
    font-size: 14px;
  }

  .footer-top { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .footer-brand-block { grid-column: 1 / -1; }
}

@media (max-width: 767px) {
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: minmax(0, 1fr); }
}

@media (max-width: 640px) {
  :root { --gutter: 20px; }

  body { font-size: 16px; }

  .header-inner { min-height: 60px; gap: 12px; }
  .brand-tagline { display: none; }
  .brand-name { font-size: 18px; }
  .brand-mark { width: 32px; height: 32px; font-size: 18px; }

  .footer-top { grid-template-columns: minmax(0, 1fr); gap: 34px; }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }
  .footer-legal { margin-left: 0; }

  .footer-contact-row { grid-template-columns: minmax(0, 1fr); gap: 4px; }

  .to-top { right: 14px; bottom: 14px; width: 42px; height: 42px; }

  .chapter-head { flex-wrap: wrap; gap: 10px; }
}

/* =========================================================
   14. 降低动效 / 打印
   ========================================================= */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  html.js [data-reveal] {
    opacity: 1;
    transform: none;
  }
  .read-progress__bar { transition: none; }
  .to-top { transition: none; }
}

@media print {
  .site-header,
  .site-footer,
  .read-progress,
  .to-top { display: none !important; }
  body { background: #FFFFFF; }
}