/* ==========================================================================
   竞博坐标 /assets/site.css —— 共享外壳样式
   深空蓝基底 · 电子青交互 · 信号橙状态 · 坐标网格语汇
   ========================================================================== */

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-space) + 12px);
}

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

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

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

button, input, select, textarea { font: inherit; color: inherit; }

button { background: none; border: 0; }

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

hr { border: 0; border-top: 1px solid var(--rule); }

/* ---------- 2. 变量 ---------- */
:root {
  /* 品牌色 */
  --ink-900: #0B1F3A;
  --ink-800: #0F2A4D;
  --ink-700: #123458;
  --rule: #1D4A7A;
  --rule-soft: rgba(29, 74, 122, 0.55);
  --mist: #6E8AA8;
  --fog: #EDF2F8;
  --cyan: #00E5FF;
  --signal: #FF6B35;
  --mint: #5FE3B0;
  --amber: #FFC94A;

  /* 文字层级 */
  --text-dark: #C3D3E3;
  --text-dark-dim: #8FA9C4;
  --text-light: #0B1F3A;
  --text-light-dim: #4A6C8F;

  /* 字体 */
  --font-display: "Archivo", "Inter Tight", "HarmonyOS Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: "Inter", "HarmonyOS Sans SC", "Source Han Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* 尺寸与节奏 */
  --rail: 1240px;
  --gutter: clamp(18px, 4vw, 40px);
  --measure: 44em;
  --notch: 18px;
  --header-space: 82px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

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

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.14;
  color: var(--fog);
}

code, kbd, samp, .mono { font-family: var(--font-mono); }

::selection {
  background: var(--cyan);
  color: #04121F;
}

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

/* ---------- 4. 布局工具 ---------- */
.container {
  width: 100%;
  max-width: var(--rail);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.container--narrow { max-width: 860px; }

.section { padding-block: clamp(56px, 8vw, 104px); }
.section--tight { padding-block: clamp(36px, 5vw, 64px); }

.band-dark { background-color: var(--ink-900); color: var(--text-dark); }
.band-mid { background-color: var(--ink-800); color: var(--text-dark); }
.band-light { background-color: var(--fog); color: var(--text-light); }

.band-light h1,
.band-light h2,
.band-light h3,
.band-light h4 { color: var(--ink-900); }

.stack { display: flex; flex-direction: column; gap: clamp(14px, 2vw, 22px); }
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 32px);
}

.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: 1 / -1; }

/* ---------- 5. 文字组件 ---------- */
.display {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(40px, 7vw, 96px);
  line-height: 0.98;
  letter-spacing: 0.02em;
  color: var(--fog);
}

.band-light .display { color: var(--ink-900); }

.h-section {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(26px, 3.4vw, 44px);
  line-height: 1.12;
  letter-spacing: 0.01em;
}

h3 { font-size: clamp(19px, 2vw, 23px); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: currentColor;
  flex: none;
}

.band-light .eyebrow { color: #00697F; }

.index-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--signal);
}

.lead {
  font-size: clamp(18px, 1.6vw, 20px);
  line-height: 1.7;
  color: var(--fog);
}

.band-light .lead { color: var(--text-light-dim); }

.prose {
  max-width: var(--measure);
  font-size: 17px;
  line-height: 1.75;
}

.prose p + p { margin-top: 1.4em; }

.rich a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 0.22em;
  text-decoration-thickness: 1px;
}

.band-light .rich a { color: #00697F; }

.rich ul,
.rich ol { margin-top: 1.2em; padding-left: 1.2em; }
.rich ul { list-style: square; }
.rich ol { list-style: decimal; }
.rich li + li { margin-top: 0.6em; }

.muted { color: var(--mist); }
.band-light .muted { color: var(--text-light-dim); }

/* ---------- 6. 按钮与徽标 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 20px;
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  line-height: 1.2;
  white-space: nowrap;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: transparent;
  color: var(--fog);
  cursor: pointer;
  transition: background-color 0.22s var(--ease), border-color 0.22s var(--ease),
    color 0.22s var(--ease), transform 0.22s var(--ease);
}

.btn:hover {
  text-decoration: none;
  transform: translateY(-2px);
}

.btn:active { transform: translateY(0); }

.btn-ghost { color: var(--text-dark); }
.btn-ghost:hover { color: var(--cyan); border-color: var(--cyan); }

.btn-signal {
  background-color: var(--signal);
  border-color: var(--signal);
  color: #12203A;
}
.btn-signal:hover { background-color: #FF8659; border-color: #FF8659; color: #12203A; }

.btn-cyan {
  background-color: var(--cyan);
  border-color: var(--cyan);
  color: #04202B;
}
.btn-cyan:hover { background-color: #5CEEFF; border-color: #5CEEFF; color: #04202B; }

.band-light .btn-ghost { color: var(--ink-900); }
.band-light .btn-ghost:hover { color: #00697F; border-color: #00697F; }

.chip {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.06em;
  line-height: 1.5;
  white-space: nowrap;
  border: 1px solid var(--rule);
  border-radius: 999px;
  color: var(--text-dark-dim);
}

.chip-version {
  color: var(--signal);
  border-color: rgba(255, 107, 53, 0.5);
  background-color: rgba(255, 107, 53, 0.1);
}

.chip-region {
  color: var(--cyan);
  border-color: rgba(0, 229, 255, 0.45);
  background-color: rgba(0, 229, 255, 0.08);
}

/* ---------- 7. 跳至内容 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 16px;
  z-index: 200;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: #04202B;
  background-color: var(--cyan);
  border-radius: 4px;
  transform: translateY(-180%);
  transition: transform 0.2s var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
  text-decoration: none;
}

/* ---------- 8. 页头 ---------- */
.site-header {
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  z-index: 80;
  padding: 14px var(--gutter);
  transition: padding 0.3s var(--ease);
}

.site-header.is-pinned { padding-top: 8px; padding-bottom: 8px; }

.header-rail {
  position: relative;
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 14px;
  max-width: var(--rail);
  margin-inline: auto;
}

/* 品牌浮岛 */
.brand-island {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 7px 14px 7px 9px;
  background-color: var(--ink-900);
  border: 1px solid var(--rule);
  border-radius: 999px;
  box-shadow: 0 8px 26px rgba(4, 12, 24, 0.45);
  transition: border-color 0.24s var(--ease), transform 0.24s var(--ease);
}

.brand-island:hover {
  border-color: rgba(0, 229, 255, 0.6);
  transform: translateY(-2px);
  text-decoration: none;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 30px;
  height: 30px;
  flex: none;
  border: 1px solid var(--rule);
  border-radius: 50%;
  background-color: rgba(0, 229, 255, 0.06);
}

.brand-lockup {
  display: flex;
  flex-direction: column;
  line-height: 1.1;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--fog);
}

.brand-sub {
  font-family: var(--font-mono);
  font-size: 9.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}

.brand-chips {
  display: inline-flex;
  gap: 6px;
  margin-left: 2px;
}

/* 导航胶囊 */
.nav-island {
  position: relative;
  justify-self: center;
  display: flex;
  align-items: center;
  padding: 6px;
  background-color: rgba(11, 31, 58, 0.88);
  border: 1px solid var(--rule);
  border-radius: 999px;
  box-shadow: 0 10px 32px rgba(4, 12, 24, 0.42);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 2px;
}

.nav-link {
  display: inline-block;
  padding: 8px 14px;
  font-size: 14px;
  letter-spacing: 0.02em;
  color: #A9C0D8;
  border: 1px solid transparent;
  border-radius: 999px;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease),
    background-color 0.2s var(--ease);
}

.nav-link:hover {
  color: var(--fog);
  background-color: rgba(0, 229, 255, 0.07);
  text-decoration: none;
}

.nav-link[aria-current="page"] {
  color: var(--cyan);
  border-color: var(--cyan);
  background-color: rgba(0, 229, 255, 0.08);
}

/* 移动端切换按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  padding: 8px 16px;
  font-size: 14px;
  letter-spacing: 0.06em;
  color: var(--fog);
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  transition: border-color 0.2s var(--ease), color 0.2s var(--ease);
}

.nav-toggle:hover { border-color: rgba(0, 229, 255, 0.5); color: var(--cyan); }

.nav-toggle-bars {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
  width: 16px;
}

.nav-toggle-bars i {
  display: block;
  height: 1.5px;
  background-color: currentColor;
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}

.nav-island[data-open="true"] .nav-toggle-bars i:first-child {
  transform: translateY(2.75px) rotate(45deg);
}

.nav-island[data-open="true"] .nav-toggle-bars i:last-child {
  transform: translateY(-2.75px) rotate(-45deg);
}

/* 页头行动区 */
.header-actions {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 8px;
}

.header-actions .btn {
  padding: 8px 15px;
  font-size: 13.5px;
}

/* 阅读进度刻度 */
.header-progress {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 2px;
  background-color: rgba(29, 74, 122, 0.35);
  pointer-events: none;
}

.header-progress-bar {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(0);
  transform-origin: left center;
  background-image: linear-gradient(90deg, var(--cyan) 0%, var(--cyan) 55%, var(--signal) 100%);
}

/* ---------- 9. 页脚 ---------- */
.site-footer {
  position: relative;
  background-color: var(--ink-900);
  color: var(--text-dark);
  border-top: 1px solid var(--rule);
}

.footer-scale {
  position: relative;
  height: 30px;
  overflow: hidden;
  border-bottom: 1px solid var(--rule);
}

.footer-scale::before {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 16px;
  background-image:
    repeating-linear-gradient(to right, var(--rule-soft) 0 1px, transparent 1px 18px),
    repeating-linear-gradient(to right, var(--rule) 0 1px, transparent 1px 90px);
  background-size: auto 50%, auto 100%;
  background-position: left bottom, left bottom;
  background-repeat: repeat-x, repeat-x;
}

.footer-rail {
  max-width: var(--rail);
  margin-inline: auto;
  padding: clamp(48px, 6vw, 72px) var(--gutter) 30px;
}

.footer-top {
  display: grid;
  grid-template-columns: 1.5fr 0.8fr 0.8fr 0.8fr 1.4fr;
  gap: clamp(28px, 3vw, 40px);
  padding-bottom: clamp(36px, 5vw, 56px);
  border-bottom: 1px solid var(--rule);
}

.footer-brand-link {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--fog);
}

.footer-brand-link:hover { color: var(--cyan); text-decoration: none; }

.footer-brand-note {
  margin-top: 14px;
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-dark-dim);
}

.footer-brand-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 18px;
}

.footer-col-title {
  padding-bottom: 12px;
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.16em;
  color: var(--cyan);
  border-bottom: 1px solid var(--rule-soft);
}

.footer-links li + li { margin-top: 11px; }

.footer-links a {
  position: relative;
  display: inline-block;
  font-size: 14.5px;
  color: #A9C0D8;
  transition: color 0.2s var(--ease);
}

.footer-links a::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1px;
  background-color: var(--cyan);
  transition: width 0.22s var(--ease);
}

.footer-links a:hover { color: var(--fog); text-decoration: none; }
.footer-links a:hover::after { width: 100%; }

.footer-contact-list { display: grid; gap: 14px; }

.footer-contact-list li { display: grid; gap: 4px; }

.footer-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--mist);
}

.footer-value {
  font-size: 14.5px;
  line-height: 1.65;
  color: var(--text-dark);
  overflow-wrap: anywhere;
}

.footer-value--mono {
  font-family: var(--font-mono);
  font-size: 13.5px;
  letter-spacing: 0.03em;
  color: var(--cyan);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 28px;
  padding-top: 26px;
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.footer-version { color: var(--cyan); }
.footer-legal { color: var(--mist); }

.footer-closing {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--signal);
}

/* ---------- 10. 通用组件 ---------- */
.panel {
  position: relative;
  padding: clamp(20px, 3vw, 30px);
  background-color: var(--ink-800);
  color: var(--text-dark);
  clip-path: polygon(0 0, calc(100% - var(--notch)) 0, 100% var(--notch), 100% 100%, 0 100%);
  transition: transform 0.2s var(--ease), background-color 0.2s var(--ease);
}

a.panel:hover,
a.panel:focus-visible {
  transform: translateY(-2px);
  text-decoration: none;
  background-color: var(--ink-700);
}

.band-light .panel {
  background-color: #FFFFFF;
  color: var(--text-light);
}

.band-light a.panel:hover,
.band-light a.panel:focus-visible { background-color: #FFFFFF; }

.panel-title {
  font-family: var(--font-display);
  font-size: clamp(18px, 1.8vw, 22px);
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--fog);
}

.band-light .panel-title { color: var(--ink-900); }

.panel-note {
  margin-top: 10px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--text-dark-dim);
}

.band-light .panel-note { color: var(--text-light-dim); }

/* 图片容器基础规则 */
.media-frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background-color: var(--ink-800);
  background-image:
    linear-gradient(to right, rgba(29, 74, 122, 0.75) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(29, 74, 122, 0.75) 1px, transparent 1px);
  background-size: 44px 44px, 44px 44px;
  clip-path: polygon(0 0, calc(100% - var(--notch)) 0, 100% var(--notch), 100% 100%, 0 100%);
}

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

.media-frame::after {
  content: "";
  position: absolute;
  left: 14px;
  bottom: 14px;
  width: 9px;
  height: 9px;
  border: 1px solid var(--cyan);
  border-radius: 50%;
  box-shadow: 0 0 0 4px rgba(0, 229, 255, 0.12);
  pointer-events: none;
}

.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--wide { aspect-ratio: 21 / 9; }

/* 刻度带 */
.scale-band {
  position: relative;
  height: 44px;
  overflow: hidden;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  background-color: var(--ink-900);
}

.scale-band::before {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 22px;
  background-image:
    repeating-linear-gradient(to right, rgba(110, 138, 168, 0.45) 0 1px, transparent 1px 16px),
    repeating-linear-gradient(to right, var(--rule) 0 1px, transparent 1px 96px);
  background-size: auto 45%, auto 100%;
  background-position: left bottom, left bottom;
  background-repeat: repeat-x, repeat-x;
}

.scale-band-label {
  position: absolute;
  top: 8px;
  left: var(--gutter);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}

.band-light .scale-band {
  background-color: var(--fog);
  border-color: rgba(29, 74, 122, 0.35);
}

.band-light .scale-band-label { color: var(--text-light-dim); }

/* 面包屑 */
.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.breadcrumbs li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.breadcrumbs li + li::before {
  content: "/";
  color: var(--rule);
}

.breadcrumbs a { color: var(--mist); }
.breadcrumbs a:hover { color: var(--cyan); text-decoration: none; }
.breadcrumbs [aria-current="page"] { color: var(--fog); }

.band-light .breadcrumbs { color: var(--text-light-dim); }
.band-light .breadcrumbs a { color: var(--text-light-dim); }
.band-light .breadcrumbs a:hover { color: #00697F; }
.band-light .breadcrumbs [aria-current="page"] { color: var(--ink-900); }

/* ---------- 11. 滚动显形 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.45s var(--ease), transform 0.45s var(--ease);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

html:not(.has-js) [data-reveal] {
  opacity: 1;
  transform: none;
}

/* ---------- 12. 响应式 ---------- */
@media (max-width: 1180px) {
  .nav-link { padding: 8px 11px; font-size: 13.5px; }
  .header-actions .btn { padding: 8px 13px; font-size: 13px; }
}

@media (max-width: 1080px) {
  .footer-top {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .footer-brand,
  .footer-contact { grid-column: 1 / -1; }
}

@media (max-width: 1024px) {
  :root { --header-space: 78px; }

  .header-rail {
    grid-template-columns: 1fr auto;
    gap: 12px;
  }

  .brand-island { justify-self: start; }

  .nav-island { justify-self: end; }

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

  .nav-list {
    position: absolute;
    top: calc(100% + 10px);
    right: 0;
    min-width: 232px;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 8px;
    background-color: rgba(11, 31, 58, 0.97);
    border: 1px solid var(--rule);
    border-radius: 20px;
    box-shadow: 0 18px 40px rgba(4, 12, 24, 0.5);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: opacity 0.2s var(--ease), transform 0.2s var(--ease), visibility 0.2s;
  }

  .nav-island[data-open="true"] .nav-list {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .nav-link {
    display: block;
    width: 100%;
    padding: 11px 14px;
    font-size: 15px;
    border-radius: 12px;
  }

  .nav-link[aria-current="page"] { border-radius: 12px; }

  .header-actions { display: none; }

  .site-header.is-pinned .nav-island { box-shadow: 0 8px 22px rgba(4, 12, 24, 0.5); }
}

@media (max-width: 900px) {
  .col-4,
  .col-5,
  .col-6,
  .col-7,
  .col-8 { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  :root { --header-space: 74px; }

  body { font-size: 16px; }

  .brand-lockup { display: none; }
  .brand-island { padding: 6px 10px 6px 7px; }
  .brand-chips { margin-left: 0; }

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

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

  .media-frame { aspect-ratio: 4 / 3; }
  .media-frame--wide { aspect-ratio: 16 / 9; }
}

@media (max-width: 400px) {
  .chip-region { display: none; }
}

/* ---------- 13. 减少动态 ---------- */
@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;
  }

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

  .btn:hover,
  .brand-island:hover,
  a.panel:hover {
    transform: none;
  }
}