/* ============================================================
   /assets/site.css — 必一体育中文站 共享外壳与基础组件
   ============================================================ */

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

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

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

/* ---------- 2. 设计令牌 ---------- */
:root {
  --ink: #08111F;
  --panel: #111D2F;
  --panel-up: #1B2A42;
  --line: #2B3B53;
  --line-soft: #22314A;
  --white: #F3F7FD;
  --muted: #93A4BD;
  --muted-dim: #6C7F9B;
  --red: #E23B3B;
  --red-deep: #971F2B;
  --yellow: #F4C430;
  --yellow-soft: #FFE49A;
  --teal: #2FC3B0;

  --font-sans: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", SFMono-Regular, Consolas, "Courier New", monospace;

  --max: 1440px;
  --gutter: 24px;
  --header-h: 76px;
  --radius: 2px;
  --dur: 160ms;
  --ease: cubic-bezier(.2, .6, .3, 1);
}

/* ---------- 3. 基础排版 ---------- */
body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: .01em;
  color: var(--white);
  background-color: var(--ink);
  background-image:
    linear-gradient(to right, rgba(43, 59, 83, .30) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(43, 59, 83, .30) 1px, transparent 1px);
  background-size: 88px 88px, 88px 88px;
  background-position: center top;
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -.02em;
  color: var(--white);
}
h1 { font-size: clamp(34px, 5.2vw, 64px); line-height: 1.06; }
h2 { font-size: clamp(26px, 3.4vw, 38px); }
h3 { font-size: clamp(19px, 2vw, 24px); line-height: 1.24; }
h4 { font-size: 17px; line-height: 1.4; }

p { color: var(--muted); }
strong { color: var(--white); font-weight: 700; }

a { text-decoration: none; }

:focus-visible {
  outline: 2px solid var(--yellow-soft);
  outline-offset: 2px;
}
:focus:not(:focus-visible) { outline: none; }

::selection { background: var(--yellow); color: var(--ink); }

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: .02em;
}

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

.hairline {
  height: 0;
  border: 0;
  border-top: 1px solid var(--line);
  margin: 32px 0;
}

/* ---------- 4. 布局容器 ---------- */
.container {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

.main-offset { padding-top: calc(var(--header-h) + 32px); }

.section { padding: 72px 0; }
.section--tight { padding: 40px 0; }

.section__title {
  font-size: clamp(26px, 3.4vw, 36px);
  font-weight: 900;
  letter-spacing: -.02em;
  line-height: 1.16;
}

.grid { display: grid; gap: 24px; }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }

.span-3 { grid-column: span 3; }
.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-9 { grid-column: span 9; }

/* ---------- 5. 跳转链接 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 300;
  transform: translateY(-180%);
  padding: 10px 18px;
  background: var(--yellow);
  color: var(--ink);
  font-size: 14px;
  font-weight: 700;
  line-height: 1.2;
  border-radius: var(--radius);
  transition: transform var(--dur) var(--ease);
}
.skip-link:focus { transform: none; }

/* ---------- 6. 页头 ---------- */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 120;
  background: rgba(8, 17, 31, .97);
  border-bottom: 1px solid var(--line);
  transition: background-color var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}

.site-header[data-overlay="true"] {
  background: transparent;
  border-bottom-color: transparent;
}

.site-header[data-overlay="true"] .site-nav__link { color: #C9D6E8; }

.site-header__inner {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--gutter);
  min-height: var(--header-h);
  display: flex;
  align-items: center;
  gap: 28px;
}

.site-header__progress {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 2px;
  transform: scaleX(var(--progress, 0));
  transform-origin: left center;
  background: linear-gradient(90deg, var(--red), var(--yellow));
  pointer-events: none;
}

/* 品牌标记：红黄双罚牌 */
.brand-mark {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--white);
  flex: 0 0 auto;
}
.site-header__brand { flex: 0 0 auto; }

.brand-mark__cards {
  display: flex;
  align-items: flex-end;
  gap: 4px;
  height: 26px;
}
.brand-mark__card {
  display: block;
  width: 11px;
  border-radius: 1px;
  transition: transform var(--dur) var(--ease);
}
.brand-mark__card--red { height: 26px; background: var(--red); }
.brand-mark__card--yellow { height: 18px; background: var(--yellow); }
.brand-mark:hover .brand-mark__card--yellow { transform: translateY(-4px); }

.brand-mark__text { display: flex; flex-direction: column; gap: 1px; }
.brand-mark__name {
  font-size: 17px;
  font-weight: 900;
  letter-spacing: .04em;
  line-height: 1.1;
}
.brand-mark__sub {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: .16em;
  color: var(--muted);
  line-height: 1.4;
  text-transform: uppercase;
}

/* 移动菜单按钮 */
.nav-toggle {
  display: none;
  margin-left: auto;
  align-items: center;
  gap: 10px;
  padding: 9px 13px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--white);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: .08em;
  cursor: pointer;
  transition: border-color var(--dur) var(--ease), color var(--dur) var(--ease);
}
.nav-toggle:hover { border-color: var(--yellow); color: var(--yellow-soft); }
.nav-toggle__bars { display: flex; flex-direction: column; gap: 4px; width: 16px; }
.nav-toggle__bars span {
  display: block;
  height: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) { transform: translateY(3px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) { transform: translateY(-3px) rotate(-45deg); }
.nav-toggle__label { line-height: 1; }

/* 主导航 */
.site-nav {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-left: auto;
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: 2px;
}
.site-nav__item { flex: 0 0 auto; }

.site-nav__link {
  position: relative;
  display: block;
  padding: 10px 12px;
  color: var(--muted);
  font-size: 15px;
  font-weight: 500;
  line-height: 1.4;
  white-space: nowrap;
  transition: color var(--dur) var(--ease);
}
.site-nav__link::after {
  content: "";
  position: absolute;
  left: 12px; right: 12px; bottom: 2px;
  height: 2px;
  background: var(--red);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform var(--dur) var(--ease);
}
.site-nav__link:hover { color: var(--white); }
.site-nav__link:hover::after { transform: scaleX(1); }
.site-nav__link[aria-current="page"] { color: var(--white); }
.site-nav__link[aria-current="page"]::after { transform: scaleX(1); }

/* 页头短入口 */
.header-utility {
  display: flex;
  align-items: center;
  border-left: 1px solid var(--line);
  padding-left: 6px;
}
.header-utility__item { flex: 0 0 auto; }
.header-utility__link {
  display: block;
  padding: 6px 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--muted);
  white-space: nowrap;
  transition: color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
.header-utility__link:hover { color: var(--yellow-soft); background: var(--panel-up); }

.site-nav__cta {
  padding: 10px 16px;
  font-size: 13px;
  white-space: nowrap;
}

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 20px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: .02em;
  color: var(--white);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  cursor: pointer;
  transition: background-color var(--dur) var(--ease),
              color var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}
.btn--primary {
  background: var(--red);
  border-color: var(--red);
  color: #fff;
  font-weight: 700;
}
.btn--primary:hover { background: var(--red-deep); border-color: var(--red-deep); }
.btn--line { border-color: var(--line); color: var(--white); }
.btn--line:hover { border-color: var(--yellow); color: var(--yellow-soft); }
.btn--ghost { border-color: transparent; color: var(--muted); padding-left: 4px; padding-right: 4px; }
.btn--ghost:hover { color: var(--yellow-soft); }

/* ---------- 8. 眉题 / 主题带 / 返回链接 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--yellow);
}
.eyebrow::before {
  content: "";
  width: 18px;
  height: 2px;
  background: var(--red);
  flex: 0 0 auto;
}

.theme-band {
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 14px 20px;
  background: var(--panel-up);
  border-left: 3px solid var(--red);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--muted);
  overflow-x: auto;
}
.theme-band span { white-space: nowrap; }

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding-bottom: 4px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
  border-bottom: 1px solid var(--line);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.back-link::before { content: "←"; }
.back-link:hover { color: var(--yellow-soft); border-bottom-color: var(--yellow); }

/* ---------- 9. 面包屑 ---------- */
.breadcrumbs { margin-bottom: 24px; }
.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
}
.breadcrumbs__item { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumbs__item:not(:last-child)::after {
  content: "/";
  color: #3A4C68;
}
.breadcrumbs__link {
  color: var(--muted);
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.breadcrumbs__link:hover { color: var(--yellow-soft); border-bottom-color: var(--yellow); }
.breadcrumbs__current { color: var(--white); }

/* ---------- 10. 面板 ---------- */
.panel {
  position: relative;
  padding: 28px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color var(--dur) var(--ease), background-color var(--dur) var(--ease);
}
.panel:hover { border-color: #3C5273; }
.panel--raised { background: var(--panel-up); }
.panel--stack {
  box-shadow: 12px 12px 0 -1px rgba(8, 17, 31, .92), 12px 12px 0 0 var(--line);
}
.panel__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 20px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}
.panel__title {
  font-size: 20px;
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -.01em;
  color: var(--white);
}
.panel__body { color: var(--muted); font-size: 15px; line-height: 1.75; }

/* ---------- 11. 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.6;
  letter-spacing: .08em;
  text-transform: uppercase;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 1px;
}
.tag--red { border-color: var(--red); color: #FFD9D9; background: rgba(226, 59, 59, .14); }
.tag--yellow { border-color: var(--yellow); color: var(--yellow-soft); background: rgba(244, 196, 48, .12); }
.tag--teal { border-color: var(--teal); color: #B8F0E8; background: rgba(47, 195, 176, .12); }

/* ---------- 12. 统计数字 ---------- */
.kpi {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 0 0;
  border-top: 2px solid var(--line);
}
.kpi__value {
  font-family: var(--font-mono);
  font-size: clamp(30px, 4vw, 44px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  font-variant-numeric: tabular-nums;
  color: var(--white);
}
.kpi__label {
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
  letter-spacing: .02em;
}
.kpi--red { border-top-color: var(--red); }
.kpi--red .kpi__value { color: var(--red); }
.kpi--yellow { border-top-color: var(--yellow); }
.kpi--yellow .kpi__value { color: var(--yellow); }
.kpi--teal { border-top-color: var(--teal); }
.kpi--teal .kpi__value { color: var(--teal); }

/* ---------- 13. 前端筛选 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.filter-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 1px;
  cursor: pointer;
  transition: color var(--dur) var(--ease),
              background-color var(--dur) var(--ease),
              border-color var(--dur) var(--ease);
}
.filter-chip:hover { color: var(--white); border-color: #3C5273; }
.filter-chip[aria-pressed="true"] {
  color: var(--ink);
  background: var(--yellow);
  border-color: var(--yellow);
  font-weight: 700;
}

.filter-empty {
  display: none;
  padding: 24px;
  border: 1px dashed var(--line);
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .04em;
  text-align: center;
}
.filter-empty[data-visible="true"] { display: block; }

[data-filter-item][hidden] { display: none !important; }

/* ---------- 14. 图片容器基础 ---------- */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background-color: var(--panel);
  background-image:
    radial-gradient(circle at 82% 16%, rgba(226, 59, 59, .22), transparent 55%),
    linear-gradient(to right, rgba(47, 195, 176, .14) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(47, 195, 176, .14) 1px, transparent 1px);
  background-size: auto, 48px 48px, 48px 48px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(8, 17, 31, 0) 46%, rgba(8, 17, 31, .62) 100%);
}
.media-frame img {
  position: relative;
  z-index: 1;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: saturate(.86) contrast(1.06) brightness(.94);
}
.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }
.media-frame--square { aspect-ratio: 1 / 1; }

.media-frame__label {
  position: absolute;
  left: 0;
  bottom: 0;
  z-index: 3;
  padding: 6px 12px;
  background: var(--red);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.5;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.media-frame__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--muted-dim);
}

/* ---------- 15. 长文 ---------- */
.prose { max-width: 760px; }
.prose > * + * { margin-top: 18px; }
.prose h2 {
  font-size: 26px;
  margin-top: 40px;
  letter-spacing: -.01em;
}
.prose h3 {
  font-size: 19px;
  margin-top: 28px;
}
.prose p {
  font-size: 16.5px;
  line-height: 1.8;
  color: var(--muted);
}
.prose ul,
.prose ol {
  padding-left: 20px;
  list-style: disc;
  color: var(--muted);
}
.prose ol { list-style: decimal; }
.prose li + li { margin-top: 8px; }
.prose a {
  color: var(--yellow-soft);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.prose a:hover { color: var(--yellow); }
.prose hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 32px 0;
}

/* ---------- 16. 页脚 ---------- */
.site-footer {
  margin-top: 96px;
  background-color: var(--panel);
  background-image: linear-gradient(to right, rgba(43, 59, 83, .40) 1px, transparent 1px);
  background-size: 64px 64px;
  background-position: center top;
  border-top: 1px solid var(--line);
}
.site-footer__inner {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 56px var(--gutter) 28px;
}
.site-footer__grid {
  display: grid;
  grid-template-columns: 1.4fr .8fr .8fr .8fr 1.5fr;
  gap: 32px;
}

.footer-brand { display: flex; flex-direction: column; align-items: flex-start; gap: 16px; }
.footer-brand__link { color: var(--white); }
.footer-brand__note {
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--muted-dim);
  max-width: 28ch;
}
.footer-brand__cta {
  margin-top: 4px;
  padding: 10px 16px;
  font-size: 13px;
}

.footer-col { min-width: 0; }
.footer-col__title {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--muted);
}
.footer-col__title::before {
  content: "";
  width: 6px;
  height: 6px;
  background: var(--red);
  flex: 0 0 auto;
}
.footer-col--legal .footer-col__title::before { background: var(--yellow); }
.footer-col--contact .footer-col__title::before { background: var(--teal); }

.footer-col__list { display: flex; flex-direction: column; gap: 2px; }
.footer-col__item { display: block; }
.footer-col__link {
  display: inline-block;
  padding: 5px 0;
  font-size: 14.5px;
  line-height: 1.5;
  color: var(--white);
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.footer-col__link:hover { color: var(--yellow-soft); border-bottom-color: var(--yellow); }
.footer-col__link[aria-current="page"] { color: var(--yellow-soft); border-bottom-color: var(--red); }

.footer-contact { display: flex; flex-direction: column; gap: 12px; }
.footer-contact__row { display: flex; flex-direction: column; gap: 1px; }
.footer-contact__key {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--muted-dim);
}
.footer-contact__value {
  font-size: 14px;
  line-height: 1.65;
  color: var(--white);
  word-break: break-word;
}

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 48px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted-dim);
}
.footer-legal__copy { color: var(--muted-dim); font-size: 12px; }
.footer-legal__links { display: flex; flex-wrap: wrap; gap: 18px; }
.footer-legal__link {
  color: var(--muted);
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}
.footer-legal__link:hover { color: var(--yellow-soft); border-bottom-color: var(--yellow); }

/* ---------- 17. 响应式 ---------- */
@media (max-width: 1240px) {
  .header-utility { display: none; }
}

@media (max-width: 1080px) {
  :root { --header-h: 68px; }

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

  body.is-nav-open { overflow: hidden; }

  .site-header[data-open="true"] {
    background: rgba(17, 29, 47, .99);
    border-bottom-color: var(--line);
  }

  .site-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 110;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    margin: 0;
    padding: 16px var(--gutter) 40px;
    background: var(--panel);
    border-top: 1px solid var(--line);
    overflow-y: auto;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    pointer-events: none;
    transition: opacity var(--dur) var(--ease),
                transform var(--dur) var(--ease),
                visibility var(--dur) var(--ease);
  }
  .site-header[data-open="true"] .site-nav,
  .site-nav[data-open="true"] {
    opacity: 1;
    visibility: visible;
    transform: none;
    pointer-events: auto;
  }

  .site-nav__list { flex-direction: column; align-items: stretch; gap: 0; }
  .site-nav__item { border-bottom: 1px solid var(--line-soft); }
  .site-nav__link {
    padding: 16px 4px;
    font-size: 17px;
    font-weight: 700;
    color: var(--white);
  }
  .site-nav__link::after { left: 4px; right: auto; width: 26px; bottom: 10px; }

  .header-utility {
    display: flex;
    flex-wrap: wrap;
    margin-top: 16px;
    padding: 8px 0 0;
    border-left: 0;
    border-top: 1px solid var(--line);
    gap: 4px;
  }
  .header-utility__link {
    padding: 8px 10px;
    font-size: 11.5px;
    border: 1px solid var(--line);
  }

  .site-nav__cta {
    margin-top: 24px;
    width: 100%;
    padding: 14px 20px;
    font-size: 15px;
  }

  .site-footer__grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 36px 28px; }
  .footer-brand { grid-column: 1 / -1; }
  .footer-col--contact { grid-column: 1 / -1; }

  .grid--12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .span-3 { grid-column: span 3; }
  .span-4, .span-5, .span-6, .span-7, .span-8, .span-9 { grid-column: span 6; }
}

@media (max-width: 720px) {
  :root { --gutter: 18px; --header-h: 62px; }

  body { font-size: 15.5px; }

  .section { padding: 52px 0; }
  .section--tight { padding: 32px 0; }

  .brand-mark__name { font-size: 15.5px; }
  .brand-mark__sub { font-size: 9px; letter-spacing: .12em; }
  .brand-mark__cards { height: 22px; }
  .brand-mark__card--red { height: 22px; }
  .brand-mark__card--yellow { height: 15px; }
  .nav-toggle__label { display: none; }

  .panel { padding: 20px; }
  .panel--stack { box-shadow: 8px 8px 0 -1px rgba(8, 17, 31, .92), 8px 8px 0 0 var(--line); }
  .panel__title { font-size: 18px; }

  .grid--12 { grid-template-columns: 1fr; gap: 18px; }
  .span-3, .span-4, .span-5, .span-6, .span-7, .span-8, .span-9 { grid-column: auto; }

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

  .site-footer { margin-top: 64px; }
  .site-footer__inner { padding: 40px var(--gutter) 24px; }
  .site-footer__grid { grid-template-columns: 1fr; gap: 30px; }
  .footer-legal { margin-top: 32px; font-size: 11.5px; }
  .footer-legal__links { gap: 14px; }
}

/* ---------- 18. 可访问性：减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
  }
  .brand-mark:hover .brand-mark__card--yellow { transform: none; }
}