/* ============================================================
   正版U蓝 · 全站共享样式 /assets/site.css
   核对室框架：固定版本条 + 左右边框导航 + 米白纸面
   ============================================================ */

/* ---------- 1. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, h4, h5, p, ul, ol, figure, blockquote, dl, dd { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }
[hidden] { display: none !important; }

/* ---------- 2. 设计令牌 ---------- */
:root {
  --ub-deep: #0B3D91;
  --ub-deep-dark: #072B66;
  --ub-teal: #00C2A8;
  --ub-gold: #E8B45A;
  --ub-paper: #F6F1E7;
  --ub-paper-light: #FBF7EF;
  --ub-stone: #D9D2C3;
  --ub-violet: #8C8B9E;
  --ub-moss: #5B6B5A;
  --ub-clay: #B96B4B;
  --ub-ink: #172033;

  --ub-line: rgba(23, 32, 51, 0.18);
  --ub-line-soft: rgba(23, 32, 51, 0.09);
  --ub-line-light: rgba(246, 241, 231, 0.18);

  --ub-vb-h: 46px;
  --ub-max: 1220px;
  --ub-gutter: clamp(18px, 4vw, 48px);
  --ub-cut: 18px;
  --ub-ease: cubic-bezier(0.22, 0.61, 0.36, 1);

  --ub-font-display: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --ub-font-body: "Noto Serif SC", "Songti SC", "Source Han Serif SC", "PingFang SC", "Microsoft YaHei", Georgia, serif;
  --ub-font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

/* ---------- 3. 基础排版 ---------- */
body {
  padding-top: var(--ub-vb-h);
  background-color: var(--ub-paper);
  background-image:
    repeating-linear-gradient(45deg, rgba(23, 32, 51, 0.018) 0 1px, transparent 1px 7px);
  color: var(--ub-ink);
  font-family: var(--ub-font-body);
  font-size: 17px;
  line-height: 1.78;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--ub-font-display);
  font-weight: 800;
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--ub-deep-dark);
}
h1 { font-size: clamp(32px, 5.6vw, 60px); }
h2 { font-size: clamp(26px, 3.8vw, 38px); }
h3 { font-size: clamp(19px, 2.3vw, 25px); font-weight: 700; }
h4 { font-size: 17px; font-weight: 700; letter-spacing: 0; }

p { max-width: 36em; }
strong, b { font-weight: 700; color: var(--ub-deep-dark); }
small { font-size: 13px; }

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

/* ---------- 4. 通用工具类 ---------- */
.mono {
  font-family: var(--ub-font-mono);
  font-weight: 600;
  letter-spacing: 0.06em;
  font-variant-numeric: tabular-nums;
}
.note {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--ub-moss);
  border-left: 2px solid var(--ub-clay);
  padding: 2px 0 2px 12px;
  max-width: 52ch;
}
.rule { height: 1px; border: 0; background: var(--ub-line); }
.rule--slant {
  height: 8px;
  border: 0;
  background: repeating-linear-gradient(115deg, var(--ub-stone) 0 10px, transparent 10px 20px);
}

/* ---------- 5. 跳过链接 ---------- */
.skip-link {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 200;
  padding: 11px 20px;
  background: var(--ub-gold);
  color: #20180A;
  font-family: var(--ub-font-display);
  font-weight: 800;
  font-size: 14px;
  transform: translateY(-140%);
  transition: transform 0.22s var(--ub-ease);
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 6. 头部外壳 ---------- */
.site-header {
  position: relative;
  background-color: var(--ub-deep);
  background-image: linear-gradient(178deg, var(--ub-deep-dark) 0%, var(--ub-deep) 62%, #0A357E 100%);
  color: var(--ub-paper);
  z-index: 40;
}
.site-header::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(45deg, rgba(246, 241, 231, 0.045) 0 1px, transparent 1px 6px);
}
.site-header > * { position: relative; z-index: 1; }

.frame {
  max-width: var(--ub-max);
  margin: 0 auto;
  padding-inline: var(--ub-gutter);
}
.site-header .frame { border-inline: 1px solid rgba(246, 241, 231, 0.14); }
.site-footer .frame { border-inline: 1px solid rgba(246, 241, 231, 0.12); }

/* 版本条 */
.version-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 90;
  height: var(--ub-vb-h);
  background: var(--ub-deep-dark);
  color: var(--ub-paper);
  border-bottom: 1px solid var(--ub-line-light);
  overflow: hidden;
}
.version-bar__inner {
  max-width: var(--ub-max);
  margin: 0 auto;
  height: 100%;
  padding-inline: var(--ub-gutter);
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--ub-font-mono);
  font-size: 12.5px;
  letter-spacing: 0.03em;
}
.version-bar__dot {
  flex: none;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--ub-teal);
  box-shadow: 0 0 0 0 rgba(0, 194, 168, 0.55);
  animation: ub-pulse 3.6s ease-in-out infinite;
}
.version-bar__text { font-weight: 600; color: var(--ub-paper); white-space: nowrap; }
.version-bar__sep { color: var(--ub-violet); }
.version-bar__note { color: rgba(246, 241, 231, 0.7); white-space: nowrap; }
.version-bar__code {
  margin-left: auto;
  color: var(--ub-gold);
  font-weight: 700;
  letter-spacing: 0.16em;
  white-space: nowrap;
}
.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: rgba(246, 241, 231, 0.12);
}
.scroll-progress span {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--ub-teal), var(--ub-gold));
  transition: width 0.1s linear;
}
@keyframes ub-pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(0, 194, 168, 0.5); }
  50% { box-shadow: 0 0 0 6px rgba(0, 194, 168, 0); }
}

/* 头部主行 */
.header-main {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: clamp(14px, 2.6vw, 36px);
  padding: 18px 0 15px;
}

.brand { display: flex; align-items: center; gap: 12px; min-width: 0; }
.brand__mark {
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  flex: none;
  background: var(--ub-teal);
  color: #04302C;
  font-family: var(--ub-font-mono);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.04em;
  clip-path: polygon(0 0, 100% 0, 100% 72%, 72% 100%, 0 100%);
}
.brand__text { display: flex; flex-direction: column; line-height: 1.24; min-width: 0; }
.brand__name {
  font-family: var(--ub-font-display);
  font-weight: 800;
  font-size: 20px;
  letter-spacing: -0.01em;
  color: var(--ub-paper);
}
.brand__tagline {
  font-family: var(--ub-font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: rgba(246, 241, 231, 0.66);
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  margin-left: auto;
  padding: 9px 13px;
  border: 1px solid rgba(232, 180, 90, 0.65);
  border-radius: 2px;
  background: rgba(7, 43, 102, 0.62);
  color: var(--ub-paper);
  font-family: var(--ub-font-display);
  font-weight: 700;
  font-size: 13px;
}
.nav-toggle__bars { display: grid; gap: 3px; width: 16px; }
.nav-toggle__bars span {
  display: block;
  height: 2px;
  background: var(--ub-gold);
  transition: transform 0.26s var(--ub-ease), opacity 0.2s linear;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) { transform: translateY(-5px) rotate(-45deg); }
.nav-toggle__label { letter-spacing: 0.08em; }

/* 导航 */
.site-nav { display: flex; margin-left: auto; }
.site-nav__list { display: flex; flex-wrap: wrap; align-items: center; gap: 2px; }
.site-nav__link {
  display: flex;
  align-items: baseline;
  gap: 6px;
  padding: 8px 10px;
  border: 1px solid transparent;
  border-radius: 2px;
  transition: background 0.22s var(--ub-ease), border-color 0.22s var(--ub-ease), color 0.22s var(--ub-ease);
}
.site-nav__idx {
  font-family: var(--ub-font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: var(--ub-teal);
}
.site-nav__label {
  font-family: var(--ub-font-display);
  font-weight: 700;
  font-size: 15px;
  color: var(--ub-paper);
}
.site-nav__link:hover {
  background: rgba(0, 194, 168, 0.16);
  border-color: rgba(0, 194, 168, 0.5);
}
.site-nav__link[aria-current="page"] {
  background: var(--ub-paper);
  border-color: var(--ub-gold);
}
.site-nav__link[aria-current="page"] .site-nav__label { color: var(--ub-deep-dark); }
.site-nav__link[aria-current="page"] .site-nav__idx { color: var(--ub-clay); }

/* 工具带 */
.tool-band {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px 16px;
  padding: 9px 0 10px;
  border-top: 1px solid rgba(246, 241, 231, 0.16);
}
.tool-band__label {
  font-family: var(--ub-font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--ub-teal);
}
.tool-band__list { display: flex; flex-wrap: wrap; gap: 8px 18px; }
.tool-band__list li { display: flex; }
.tool-band__list a {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  padding: 2px 0;
  font-size: 13.5px;
  color: rgba(246, 241, 231, 0.86);
  border-bottom: 1px dashed rgba(246, 241, 231, 0.3);
  transition: color 0.2s var(--ub-ease), border-color 0.2s var(--ub-ease);
}
.tool-band__list a::before {
  content: "";
  width: 5px;
  height: 5px;
  flex: none;
  background: var(--ub-teal);
  transform: rotate(45deg);
}
.tool-band__list a:hover { color: var(--ub-gold); border-bottom-color: var(--ub-gold); }

/* ---------- 7. 页脚 ---------- */
.site-footer {
  position: relative;
  background-color: var(--ub-deep-dark);
  color: var(--ub-paper);
  margin-top: clamp(28px, 5vw, 56px);
}
.site-footer::before {
  content: "";
  display: block;
  height: 6px;
  background: linear-gradient(90deg,
    var(--ub-gold) 0 22%,
    var(--ub-teal) 22% 46%,
    var(--ub-clay) 46% 58%,
    var(--ub-violet) 58% 100%);
}
.footer__top {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: clamp(24px, 4vw, 56px);
  padding: clamp(34px, 5.5vw, 62px) 0 clamp(22px, 3.5vw, 36px);
}
.footer__brand { display: flex; flex-direction: column; align-items: flex-start; gap: 14px; min-width: 0; }
.footer__coords {
  font-family: var(--ub-font-mono);
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--ub-teal);
}
.footer__summary {
  font-family: var(--ub-font-display);
  font-weight: 800;
  font-size: clamp(20px, 2.6vw, 26px);
  line-height: 1.32;
  letter-spacing: -0.01em;
  color: var(--ub-paper);
  max-width: 20em;
}
.footer__cta {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 12px 22px;
  background: var(--ub-gold);
  color: #20180A;
  font-family: var(--ub-font-display);
  font-weight: 800;
  font-size: 15px;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 0 100%);
  transition: transform 0.2s var(--ub-ease), filter 0.2s var(--ub-ease);
}
.footer__cta:hover { transform: translateX(3px); filter: brightness(1.06); }

.footer__nav {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(16px, 3vw, 32px);
}
.footer__group {
  min-width: 0;
  padding-left: clamp(12px, 2vw, 20px);
  border-left: 1px solid rgba(246, 241, 231, 0.14);
}
.footer__group-title {
  margin-bottom: 10px;
  font-family: var(--ub-font-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--ub-violet);
}
.footer__links { display: grid; gap: 8px; }
.footer__links a {
  width: fit-content;
  padding-bottom: 2px;
  font-size: 14.5px;
  color: rgba(246, 241, 231, 0.85);
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--ub-ease), border-color 0.2s var(--ub-ease);
}
.footer__links a:hover { color: var(--ub-teal); border-bottom-color: var(--ub-teal); }

.footer__contact {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 18px 28px;
  padding: 22px 0;
  border-top: 1px solid rgba(246, 241, 231, 0.16);
  border-bottom: 1px solid rgba(246, 241, 231, 0.16);
}
.footer__contact-item { display: flex; flex-direction: column; gap: 4px; min-width: 0; }
.footer__contact-label {
  font-family: var(--ub-font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--ub-teal);
}
.footer__contact-value {
  font-size: 14.5px;
  color: var(--ub-paper);
  overflow-wrap: anywhere;
}
.footer__note {
  grid-column: 1 / -1;
  max-width: 62ch;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(246, 241, 231, 0.62);
}
.footer__bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 24px;
  padding: 20px 0 34px;
  font-family: var(--ub-font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: rgba(246, 241, 231, 0.6);
}
.footer__icp { color: rgba(246, 241, 231, 0.7); }
.footer__legal { display: flex; flex-wrap: wrap; gap: 14px; }
.footer__legal a { transition: color 0.2s var(--ub-ease); }
.footer__legal a:hover { color: var(--ub-gold); }
.footer__stamp { color: rgba(246, 241, 231, 0.55); }

/* ---------- 8. 页面容器与章节 ---------- */
.page-shell {
  max-width: var(--ub-max);
  margin: 0 auto;
  padding-inline: var(--ub-gutter);
}
.section { padding-block: clamp(36px, 6vw, 76px); }
.section__head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px 16px;
  margin-bottom: 22px;
}
.section__num {
  font-family: var(--ub-font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--ub-clay);
}
.section__title { font-size: clamp(24px, 3.4vw, 34px); }
.section__note { font-size: 15px; color: var(--ub-moss); max-width: 34em; }

/* ---------- 9. 网格与面板 ---------- */
.grid { display: grid; gap: clamp(18px, 3vw, 32px); }
.grid--split { grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr); }
.grid--thirds { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.panel {
  position: relative;
  padding: clamp(20px, 3vw, 30px);
  background: var(--ub-paper-light);
  border: 1px solid var(--ub-line);
  clip-path: polygon(0 0, calc(100% - var(--ub-cut)) 0, 100% var(--ub-cut), 100% 100%, 0 100%);
}
.panel--deep {
  background: var(--ub-deep);
  color: var(--ub-paper);
  border-color: rgba(246, 241, 231, 0.22);
}
.panel--deep h2, .panel--deep h3 { color: var(--ub-paper); }
.panel--deep p { color: rgba(246, 241, 231, 0.84); }

/* ---------- 10. 按钮与标签 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  font-family: var(--ub-font-display);
  font-weight: 800;
  font-size: 15px;
  border: 1px solid transparent;
  transition: transform 0.18s var(--ub-ease), background 0.2s var(--ub-ease), color 0.2s var(--ub-ease), border-color 0.2s var(--ub-ease);
}
.btn--gold {
  background: var(--ub-gold);
  color: #20180A;
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 0 100%);
}
.btn--gold:hover { transform: translateY(-2px); filter: brightness(1.05); }
.btn--teal { background: var(--ub-teal); color: #04302C; }
.btn--teal:hover { transform: translateY(-2px); filter: brightness(1.05); }
.btn--ghost { background: transparent; color: var(--ub-deep); border-color: var(--ub-deep); }
.btn--ghost:hover { background: var(--ub-deep); color: var(--ub-paper); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  font-family: var(--ub-font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--ub-moss);
  background: rgba(217, 210, 195, 0.42);
  border: 1px solid var(--ub-line);
}
.tag--teal { color: #04655A; background: rgba(0, 194, 168, 0.12); border-color: var(--ub-teal); }
.tag--gold { color: #7A5212; background: rgba(232, 180, 90, 0.16); border-color: var(--ub-gold); }
.tag--clay { color: var(--ub-clay); background: rgba(185, 107, 75, 0.1); border-color: var(--ub-clay); }

/* ---------- 11. 面包屑 / 坐标 / 图例 ---------- */
.breadcrumb {
  padding: 14px 0 0;
  font-family: var(--ub-font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--ub-moss);
}
.breadcrumb__list { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.breadcrumb__item { display: inline-flex; align-items: center; }
.breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: 8px;
  color: var(--ub-violet);
}
.breadcrumb a:hover { color: var(--ub-deep); }
.breadcrumb__item[aria-current="page"] { color: var(--ub-ink); }

.coord {
  display: flex;
  flex-direction: column;
  gap: 7px;
  font-family: var(--ub-font-mono);
  font-size: 11.5px;
  letter-spacing: 0.12em;
  color: var(--ub-moss);
}
.coord__item { display: flex; align-items: center; gap: 8px; }
.coord__item::before {
  content: "";
  width: 14px;
  height: 1px;
  flex: none;
  background: var(--ub-clay);
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  font-family: var(--ub-font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--ub-moss);
}
.legend__item { display: inline-flex; align-items: center; gap: 7px; }
.legend__dot { width: 8px; height: 8px; flex: none; background: var(--ub-teal); }
.legend__dot--gold { background: var(--ub-gold); }
.legend__dot--clay { background: var(--ub-clay); }
.legend__dot--violet { background: var(--ub-violet); }

/* ---------- 12. 图片容器基础规则 ---------- */
.media-frame {
  position: relative;
  overflow: hidden;
  min-height: 160px;
  background: var(--ub-stone);
  border: 1px solid var(--ub-line);
  clip-path: polygon(0 0, calc(100% - var(--ub-cut)) 0, 100% var(--ub-cut), 100% 100%, 0 100%);
}
.media-frame::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image: repeating-linear-gradient(135deg, rgba(23, 32, 51, 0.07) 0 1px, transparent 1px 8px);
}
.media-frame__img {
  position: relative;
  width: 100%;
  height: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  filter: saturate(0.95) contrast(1.03);
}
.media-frame--tall .media-frame__img { aspect-ratio: 3 / 4; }
.media-frame--sq .media-frame__img { aspect-ratio: 1 / 1; }
.media-frame__caption {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 1;
  padding: 7px 14px;
  background: rgba(7, 43, 102, 0.88);
  color: var(--ub-paper);
  font-family: var(--ub-font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
}

/* ---------- 13. 标签页组件 ---------- */
.tabs { position: relative; }
.tabs__list {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  border-bottom: 1px solid var(--ub-line);
  scrollbar-width: thin;
}
.tabs__tab {
  flex: none;
  padding: 10px 16px;
  font-family: var(--ub-font-display);
  font-weight: 700;
  font-size: 14px;
  color: var(--ub-moss);
  white-space: nowrap;
  border: 1px solid transparent;
  border-bottom: 0;
  transition: background 0.2s var(--ub-ease), color 0.2s var(--ub-ease);
}
.tabs__tab:hover { color: var(--ub-deep); background: rgba(0, 194, 168, 0.1); }
.tabs__tab[aria-selected="true"] {
  background: var(--ub-paper-light);
  color: var(--ub-deep-dark);
  border-color: var(--ub-line);
  box-shadow: inset 0 3px 0 var(--ub-gold);
}
.tabs__panel { padding: 18px 0 0; }

/* ---------- 14. 滚动显现 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s var(--ub-ease), transform 0.5s var(--ub-ease);
}
[data-reveal].is-visible { opacity: 1; transform: none; }

/* ---------- 15. 响应式 ---------- */
@media (max-width: 1040px) {
  .footer__top { grid-template-columns: 1fr; }
  .footer__brand { max-width: 40em; }
}

@media (max-width: 900px) {
  :root { --ub-vb-h: 44px; --ub-gutter: clamp(16px, 4.5vw, 28px); }
  body { font-size: 16.5px; }

  .nav-toggle { display: inline-flex; }
  .site-nav {
    display: none;
    flex-basis: 100%;
    margin-left: 0;
    padding-top: 10px;
    border-top: 1px solid rgba(246, 241, 231, 0.2);
  }
  .site-nav[data-open="true"] { display: block; }
  .site-nav__list { flex-direction: column; align-items: stretch; gap: 4px; }
  .site-nav__link {
    width: 100%;
    padding: 12px 14px;
    background: rgba(7, 43, 102, 0.5);
    border-color: rgba(246, 241, 231, 0.14);
  }
  .site-nav__label { font-size: 16px; }
  .site-nav__idx { font-size: 11px; }

  .header-main { padding: 14px 0 12px; gap: 10px 14px; }
  .brand__mark { width: 40px; height: 40px; font-size: 13px; }
  .brand__name { font-size: 18px; }
  .brand__tagline { font-size: 10.5px; }

  .grid--split, .grid--thirds { grid-template-columns: 1fr; }
  .footer__nav { grid-template-columns: 1fr; }
  .footer__group { padding-left: 14px; }
  .footer__bottom { justify-content: flex-start; }
}

@media (max-width: 720px) {
  .version-bar__note, .version-bar__sep { display: none; }
  .version-bar__inner { font-size: 12px; }
  .tool-band { gap: 8px 12px; }
  .tool-band__label { width: 100%; }
  .footer__contact { grid-template-columns: 1fr; }
  .footer__cta { width: 100%; justify-content: center; }
  .panel { --ub-cut: 14px; }
  .media-frame__img { aspect-ratio: 4 / 3; }
}

@media (max-width: 420px) {
  .brand__tagline { display: none; }
  .version-bar__code { letter-spacing: 0.1em; font-size: 11px; }
}

/* ---------- 16. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .version-bar__dot { animation: none; box-shadow: 0 0 0 3px rgba(0, 194, 168, 0.28); }
  [data-reveal] { opacity: 1; transform: none; }
  .footer__cta:hover, .btn--gold:hover, .btn--teal:hover { transform: none; }
}