/* ============================================================
   B体育官方 · 共享样式表 /assets/site.css
   深墨绿控制台基底 · 青柠信号 · 切角面板 · 展览标签
   ============================================================ */

/* ---------- 1. 变量 ---------- */
:root{
  --ink-950:#05130F;
  --ink-900:#0A1F18;
  --ink-700:#16382C;
  --lime-400:#C9FF4A;
  --lime-100:#EBFFC2;
  --orange-500:#FF6A2E;
  --paper-050:#F4F7F3;
  --paper-200:#DCE5DE;
  --slate-400:#93A39B;
  --forest-grad:linear-gradient(135deg,#0E3327 0%,#1C6B4E 100%);

  --font-body:"Noto Sans SC","Source Han Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-display:"Barlow Condensed","Noto Sans SC","Source Han Sans SC","PingFang SC",system-ui,sans-serif;
  --font-mono:"JetBrains Mono","SFMono-Regular","Consolas","Noto Sans SC",ui-monospace,monospace;

  --shell:1240px;
  --shell-wide:1440px;
  --header-h:72px;
  --header-h-compact:56px;
  --cut:18px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --line:1px solid var(--ink-700);
}

/* ---------- 2. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:calc(var(--header-h) + 18px)}
body{
  margin:0;
  background:var(--ink-950);
  color:var(--paper-050);
  font-family:var(--font-body);
  font-size:1rem;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
img,svg,video,canvas{display:block;max-width:100%;height:auto}
ul,ol{margin:0;padding:0;list-style:none}
figure,blockquote{margin:0}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer}
input,textarea,select{font:inherit}
h1,h2,h3,h4,h5{font-family:var(--font-display);font-weight:800;line-height:1.22;letter-spacing:-.01em}
p{margin:0;text-wrap:pretty}
:focus-visible{outline:2px solid var(--lime-400);outline-offset:3px;border-radius:2px}
.section--paper :focus-visible{outline-color:#16382C}

/* ---------- 3. 文本工具 ---------- */
.mono{font-family:var(--font-mono);letter-spacing:.04em;font-size:.9375rem}
.eyebrow{
  display:inline-block;
  font-family:var(--font-mono);
  font-size:.75rem;
  font-weight:700;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:var(--lime-400);
}
.section--paper .eyebrow{color:#1C6B4E}
.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;
}
.prose{
  max-width:36em;
  display:flex;
  flex-direction:column;
  gap:1.05em;
  font-size:1.0625rem;
  line-height:1.75;
}
.prose h2{font-size:clamp(1.4rem,2.4vw,2rem)}
.prose h3{font-size:1.2rem;letter-spacing:0}
.prose ul{display:grid;gap:.5em}
.prose li{position:relative;padding-left:1.15em}
.prose li::before{
  content:"";position:absolute;left:0;top:.72em;
  width:8px;height:2px;background:var(--lime-400);
}
.prose a{color:var(--lime-400);text-decoration:underline;text-underline-offset:3px}
.section--paper .prose li::before{background:#1C6B4E}
.section--paper .prose a{color:#1C6B4E}

/* ---------- 4. 布局容器 ---------- */
.container{
  width:100%;
  max-width:var(--shell);
  margin-inline:auto;
  padding-inline:clamp(16px,4vw,48px);
}
.container--wide{max-width:var(--shell-wide)}

.section{
  position:relative;
  padding-block:clamp(48px,7vw,104px);
}
.section--tight{padding-block:clamp(28px,4vw,56px)}
.section--dark{background:var(--ink-950);color:var(--paper-050)}
.section--paper{background:var(--paper-050);color:var(--ink-950)}
.section--grad{background:var(--forest-grad);color:var(--paper-050)}

.section-head{
  display:flex;
  flex-wrap:wrap;
  align-items:flex-end;
  justify-content:space-between;
  gap:.75rem 2rem;
  margin-bottom:clamp(20px,3vw,40px);
}
.section-head__title{font-size:clamp(1.4rem,2.4vw,2rem)}
.section-head__note{
  font-family:var(--font-mono);
  font-size:.75rem;
  letter-spacing:.06em;
  line-height:1.7;
  color:var(--slate-400);
  max-width:34ch;
}

.grid{display:grid;gap:clamp(16px,2.4vw,32px);align-items:start}
.grid--8-4{grid-template-columns:minmax(0,8fr) minmax(0,4fr)}
.grid--7-5{grid-template-columns:minmax(0,7fr) minmax(0,5fr)}
.grid--trio{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}

/* ---------- 5. 展览标签 ---------- */
.exhibit-label{
  display:inline-flex;
  align-items:center;
  gap:.7rem;
  color:var(--slate-400);
  font-size:.75rem;
  font-weight:700;
  letter-spacing:.12em;
}
.exhibit-label__num{font-family:var(--font-mono);color:var(--lime-400);letter-spacing:.06em}
.exhibit-label__name{color:inherit;letter-spacing:.14em}
.exhibit-label__rule{width:24px;height:3px;background:currentColor;flex:none}
.section--paper .exhibit-label{color:#4A6357}
.section--paper .exhibit-label__num{color:#1C6B4E}
.section--paper .exhibit-label__rule{background:#1C6B4E}

/* ---------- 6. 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.5rem;
  padding:.78rem 1.35rem;
  font-size:.9rem;
  font-weight:700;
  letter-spacing:.03em;
  line-height:1.2;
  border:1px solid transparent;
  clip-path:polygon(0 0,100% 0,100% calc(100% - 10px),calc(100% - 10px) 100%,0 100%);
  transition:transform .18s var(--ease),background-color .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease);
}
.btn:hover{transform:translateY(-2px)}
.btn--primary{background:var(--lime-400);color:var(--ink-950)}
.btn--primary:hover{background:var(--lime-100)}
.btn--ghost{border-color:rgba(244,247,243,.35);color:var(--paper-050)}
.btn--ghost:hover{border-color:var(--lime-400);color:var(--lime-400)}
.section--paper .btn--ghost{border-color:rgba(5,19,15,.28);color:var(--ink-950)}
.section--paper .btn--ghost:hover{border-color:#1C6B4E;color:#1C6B4E}
.btn--signal{background:var(--orange-500);color:#0B0D08}
.btn--signal:hover{background:#FF8555}

/* ---------- 7. 面包屑 ---------- */
.breadcrumbs{margin-bottom:clamp(18px,3vw,32px)}
.breadcrumbs__list{display:flex;flex-wrap:wrap;align-items:center;gap:.35rem .6rem}
.breadcrumbs__item{
  display:inline-flex;align-items:center;gap:.6rem;
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.06em;
  color:var(--slate-400);
}
.breadcrumbs__item + .breadcrumbs__item::before{
  content:"/";color:var(--ink-700);
}
.breadcrumbs__link{color:inherit;border-bottom:1px solid transparent;transition:color .18s,border-color .18s}
.breadcrumbs__link:hover{color:var(--lime-400);border-bottom-color:var(--lime-400)}
.breadcrumbs__item[aria-current="page"]{color:var(--paper-050)}

/* ---------- 8. 面板与数据 ---------- */
.panel{
  background:var(--ink-900);
  border:var(--line);
  padding:clamp(18px,2.4vw,28px);
}
.panel--cut{clip-path:polygon(0 0,100% 0,100% calc(100% - var(--cut)),calc(100% - var(--cut)) 100%,0 100%)}
.panel--grad{background:var(--forest-grad);border-color:rgba(201,255,74,.28)}
.panel--paper{background:var(--paper-200);border-color:rgba(5,19,15,.14);color:var(--ink-950)}

.stat{display:grid;gap:.15rem}
.stat__num{
  font-family:var(--font-display);
  font-weight:800;
  font-size:clamp(2rem,4vw,3.25rem);
  line-height:1;
  letter-spacing:-.02em;
  color:var(--lime-400);
  font-variant-numeric:tabular-nums;
}
.section--paper .stat__num{color:#16382C}
.stat__label{
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.1em;
  color:var(--slate-400);
}
.section--paper .stat__label{color:#4A6357}

.chip{
  display:inline-flex;align-items:center;gap:.35rem;
  padding:.2rem .55rem;
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.08em;
  color:var(--slate-400);
  border:1px solid var(--ink-700);
  background:rgba(22,56,44,.5);
}
.chip--signal{color:var(--orange-500);border-color:rgba(255,106,46,.55);background:rgba(255,106,46,.08)}

/* ---------- 9. 索引带 ---------- */
.index-band{
  display:grid;
  grid-auto-flow:column;
  grid-auto-columns:minmax(238px,1fr);
  overflow-x:auto;
  scroll-snap-type:x proximity;
  border-top:var(--line);
  border-bottom:var(--line);
  -webkit-overflow-scrolling:touch;
}
.index-band__cell{
  position:relative;
  scroll-snap-align:start;
  padding:1.15rem clamp(14px,1.8vw,22px);
  display:grid;
  gap:.3rem;
  min-height:104px;
  align-content:start;
}
.index-band__cell + .index-band__cell::before{
  content:"";
  position:absolute;left:0;top:16%;bottom:16%;width:1px;
  background:var(--ink-700);
  transform:skewX(-24deg);
}
.index-band__num{
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.1em;
  color:var(--lime-400);
}
.index-band__text{font-size:.9375rem;line-height:1.6;color:var(--paper-050)}
.section--paper .index-band{border-color:rgba(5,19,15,.16)}
.section--paper .index-band__cell + .index-band__cell::before{background:rgba(5,19,15,.16)}
.section--paper .index-band__num{color:#1C6B4E}
.section--paper .index-band__text{color:var(--ink-950)}

/* ---------- 10. 折叠块 ---------- */
.fold{border-bottom:var(--line)}
.fold__toggle{
  display:flex;
  width:100%;
  align-items:center;
  justify-content:space-between;
  gap:1rem;
  padding:.95rem 0;
  text-align:left;
}
.fold__title{font-family:var(--font-body);font-weight:600;font-size:.98rem;letter-spacing:0}
.fold__icon{
  flex:none;
  width:24px;height:24px;
  display:grid;place-items:center;
  border:1px solid var(--ink-700);
  color:var(--lime-400);
  font-family:var(--font-mono);
  font-size:.85rem;
  line-height:1;
  transition:transform .18s var(--ease),background-color .18s var(--ease);
}
.fold__toggle:hover .fold__icon{background:rgba(201,255,74,.12)}
.fold__toggle[aria-expanded="true"] .fold__icon{transform:rotate(45deg);background:rgba(201,255,74,.16)}
.fold__panel{padding-bottom:1.1rem;font-size:.95rem}
.fold__panel[data-open="false"]{display:none}
.fold__panel[data-open="true"]{display:block;animation:foldIn .22s var(--ease) both}
.section--paper .fold{border-color:rgba(5,19,15,.16)}
.section--paper .fold__icon{border-color:rgba(5,19,15,.24);color:#1C6B4E}
@keyframes foldIn{from{opacity:0;transform:translateY(-6px)}to{opacity:1;transform:none}}

/* ---------- 11. 图片容器基础 ---------- */
.media-frame{
  position:relative;
  overflow:hidden;
  aspect-ratio:16/10;
  background:var(--ink-900);
  border:var(--line);
  clip-path:polygon(0 0,100% 0,100% calc(100% - 20px),calc(100% - 20px) 100%,0 100%);
}
.media-frame__img,
.media-frame > img{
  width:100%;height:100%;
  object-fit:cover;
  display:block;
}
.media-frame__grid{
  position:absolute;inset:0;
  pointer-events:none;
  opacity:.5;
  background-image:
    repeating-linear-gradient(to right,rgba(201,255,74,.16) 0 1px,transparent 1px 8px),
    repeating-linear-gradient(to bottom,rgba(201,255,74,.16) 0 1px,transparent 1px 8px);
  mix-blend-mode:screen;
}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--square{aspect-ratio:1/1}
.media-frame--tall{aspect-ratio:4/5}
.section--paper .media-frame{border-color:rgba(5,19,15,.16)}

/* ---------- 12. 分隔斜块 ---------- */
.divider-slash{
  height:clamp(28px,5vw,58px);
  background:linear-gradient(135deg,rgba(28,107,78,.55) 0%,rgba(201,255,74,.22) 100%);
  clip-path:polygon(0 58%,100% 0,100% 38%,0 100%);
}

/* ---------- 13. 跳转链接 ---------- */
.skip-link{
  position:fixed;
  top:8px;left:8px;
  z-index:200;
  padding:.6rem 1rem;
  background:var(--lime-400);
  color:var(--ink-950);
  font-weight:700;
  font-size:.85rem;
  transform:translateY(-160%);
  transition:transform .18s var(--ease);
}
.skip-link:focus{transform:translateY(0)}

/* ---------- 14. 页头 ---------- */
.site-header{
  position:sticky;
  top:0;
  z-index:60;
  background:rgba(5,19,15,.96);
  border-bottom:1px solid var(--ink-700);
  isolation:isolate;
}
.header-progress{
  position:absolute;
  left:0;right:0;bottom:-1px;
  height:2px;
  pointer-events:none;
  overflow:hidden;
}
.header-progress__bar{
  display:block;
  height:100%;width:100%;
  transform:scaleX(0);
  transform-origin:0 50%;
  background:linear-gradient(90deg,var(--lime-400) 0%,var(--orange-500) 100%);
  transition:transform .1s linear;
}
.site-header__inner{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:1.5rem;
  min-height:var(--header-h);
  transition:min-height .2s var(--ease);
}
.site-header.is-compact .site-header__inner{min-height:var(--header-h-compact)}

.brand{display:flex;align-items:center;gap:.7rem;min-width:0}
.brand__mark{
  flex:none;
  width:38px;height:38px;
  display:grid;place-items:center;
  background:var(--lime-400);
  color:var(--ink-950);
  font-family:var(--font-display);
  font-weight:800;
  font-size:1.5rem;
  line-height:1;
  clip-path:polygon(0 0,100% 0,100% 68%,68% 100%,0 100%);
  transition:width .2s var(--ease),height .2s var(--ease);
}
.site-header.is-compact .brand__mark{width:32px;height:32px;font-size:1.25rem}
.brand__meta{display:flex;flex-direction:column;gap:.1rem;min-width:0}
.brand__name{
  display:inline-flex;align-items:center;gap:.45rem;
  font-family:var(--font-body);
  font-weight:700;
  font-size:.98rem;
  letter-spacing:.02em;
  color:var(--paper-050);
  white-space:nowrap;
}
.brand__tag{
  font-family:var(--font-mono);
  font-size:.62rem;
  font-weight:700;
  letter-spacing:.08em;
  padding:.1rem .3rem;
  color:var(--lime-400);
  border:1px solid rgba(201,255,74,.45);
  line-height:1.4;
}
.brand__line{
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.08em;
  color:var(--slate-400);
  white-space:nowrap;
}

.nav{display:flex;align-items:center;gap:.5rem}
.nav__list{display:flex;align-items:center;gap:clamp(.85rem,1.6vw,1.7rem)}
.nav__item{display:block}
.nav__link{
  position:relative;
  display:inline-block;
  padding:.5rem .1rem;
  font-size:.875rem;
  letter-spacing:.03em;
  color:rgba(244,247,243,.76);
  transition:color .18s var(--ease);
}
.nav__link::after{
  content:"";
  position:absolute;
  left:.1rem;bottom:.15rem;
  width:0;height:2px;
  background:var(--lime-400);
  transition:width .18s var(--ease);
}
.nav__link:hover{color:var(--paper-050)}
.nav__link:hover::after{width:56%}
.nav__link[aria-current="page"]{color:var(--lime-400)}
.nav__link[aria-current="page"]::after{width:22px}
.nav__cta{
  margin-left:clamp(.75rem,1.4vw,1.5rem);
  flex:none;
  padding:.5rem .9rem;
  font-size:.8rem;
  font-weight:700;
  letter-spacing:.04em;
  color:var(--lime-400);
  border:1px solid rgba(201,255,74,.5);
  clip-path:polygon(0 0,100% 0,100% calc(100% - 8px),calc(100% - 8px) 100%,0 100%);
  transition:background-color .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease);
}
.nav__cta:hover{background:var(--lime-400);color:var(--ink-950);border-color:var(--lime-400)}

.nav__toggle{
  display:none;
  align-items:center;
  gap:.55rem;
  padding:.45rem .7rem;
  border:1px solid var(--ink-700);
  color:var(--paper-050);
  font-size:.78rem;
  letter-spacing:.1em;
  clip-path:polygon(0 0,100% 0,100% calc(100% - 8px),calc(100% - 8px) 100%,0 100%);
}
.nav__toggle-bars{position:relative;display:block;width:18px;height:2px;background:var(--lime-400);transition:background-color .18s var(--ease)}
.nav__toggle-bars::before,
.nav__toggle-bars::after{
  content:"";position:absolute;left:0;
  width:18px;height:2px;background:var(--lime-400);
  transition:transform .18s var(--ease),top .18s var(--ease);
}
.nav__toggle-bars::before{top:-6px}
.nav__toggle-bars::after{top:6px}
.nav__toggle-text{font-family:var(--font-mono)}
.site-header[data-open="true"] .nav__toggle{border-color:rgba(201,255,74,.55)}
.site-header[data-open="true"] .nav__toggle-bars{background:transparent}
.site-header[data-open="true"] .nav__toggle-bars::before{top:0;transform:rotate(45deg)}
.site-header[data-open="true"] .nav__toggle-bars::after{top:0;transform:rotate(-45deg)}

.nav-scrim{
  position:fixed;inset:0;
  z-index:50;
  background:rgba(5,19,15,.68);
  opacity:0;
  pointer-events:none;
  transition:opacity .22s var(--ease);
}
.site-header[data-open="true"] .nav-scrim{opacity:1;pointer-events:auto}

/* ---------- 15. 页脚 ---------- */
.site-footer{
  position:relative;
  background:var(--ink-950);
  color:var(--paper-050);
  border-top:1px solid var(--ink-700);
}
.footer-slash{
  height:clamp(36px,5vw,58px);
  background:linear-gradient(135deg,#0E3327 0%,#1C6B4E 46%,#C9FF4A 100%);
  clip-path:polygon(0 0,100% 0,100% 16%,0 100%);
}
.site-footer__inner{padding-block:clamp(36px,5.5vw,68px) 0}
.footer-grid{
  display:grid;
  grid-template-columns:minmax(220px,1.4fr) minmax(140px,.85fr) minmax(220px,1.2fr) minmax(120px,.6fr);
  gap:clamp(24px,3.4vw,52px);
  padding-bottom:clamp(28px,4vw,48px);
}
.footer-col{display:grid;gap:.85rem;align-content:start;min-width:0}
.footer-col--brand{gap:.7rem}
.footer-brand__mark{
  display:inline-flex;align-items:center;gap:.5rem;
  font-family:var(--font-display);
  font-weight:800;
  font-size:1.15rem;
  letter-spacing:.02em;
}
.footer-brand__mark::before{
  content:"";width:12px;height:12px;background:var(--lime-400);
  clip-path:polygon(0 0,100% 0,100% 60%,60% 100%,0 100%);
}
.footer-brand__text{font-size:.85rem;line-height:1.75;color:rgba(244,247,243,.72);max-width:30em}
.footer-icp,.footer-mono{
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.04em;
  color:var(--slate-400);
}
.footer-title{
  font-family:var(--font-mono);
  font-weight:700;
  font-size:.72rem;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:var(--slate-400);
}
.footer-links,.footer-legal{display:grid;gap:.5rem}
.footer-link{
  display:inline-block;
  font-size:.88rem;
  color:rgba(244,247,243,.8);
  border-bottom:1px solid transparent;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.footer-link:hover{color:var(--lime-400);border-bottom-color:rgba(201,255,74,.5)}
.footer-contact{display:grid;gap:.7rem}
.footer-contact__item{
  display:flex;flex-wrap:wrap;align-items:center;gap:.4rem .55rem;
  color:rgba(244,247,243,.82);
}
.footer-contact__value{
  font-family:var(--font-mono);
  font-size:.78rem;
  letter-spacing:.02em;
  overflow-wrap:anywhere;
}
.footer-contact__copy{
  font-family:var(--font-mono);
  font-size:.66rem;
  letter-spacing:.06em;
  padding:.12rem .4rem;
  color:var(--slate-400);
  border:1px solid var(--ink-700);
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.footer-contact__copy:hover{color:var(--lime-400);border-color:rgba(201,255,74,.55)}
.footer-contact__copy.is-copied{color:var(--lime-400);border-color:var(--lime-400)}
.footer-note{
  font-size:.75rem;
  line-height:1.7;
  color:var(--slate-400);
}
.footer-bottom{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:.6rem 1.5rem;
  padding-block:1.15rem 1.35rem;
  border-top:1px solid var(--ink-700);
}

.to-top{
  position:fixed;
  right:clamp(14px,3vw,28px);
  bottom:clamp(14px,3vw,28px);
  z-index:80;
  width:48px;height:48px;
  display:grid;place-items:center;
  background:var(--ink-900);
  border:1px solid var(--ink-700);
  color:var(--lime-400);
  font-size:1rem;
  clip-path:polygon(0 0,100% 0,100% calc(100% - 12px),calc(100% - 12px) 100%,0 100%);
  opacity:0;
  pointer-events:none;
  transform:translateY(10px);
  transition:opacity .2s var(--ease),transform .2s var(--ease),background-color .18s var(--ease),color .18s var(--ease);
}
.to-top.is-visible{opacity:1;pointer-events:auto;transform:none}
.to-top:hover{background:var(--lime-400);color:var(--ink-950);border-color:var(--lime-400)}

/* ---------- 16. 响应式 ---------- */
@media (max-width:1024px){
  .grid--8-4,.grid--7-5{grid-template-columns:minmax(0,1fr)}
  .grid--trio{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}

@media (max-width:900px){
  .site-header__inner{min-height:var(--header-h-compact)}
  .nav__toggle{display:inline-flex}
  .nav{
    position:fixed;
    top:0;left:0;bottom:0;
    z-index:55;
    width:min(86vw,340px);
    flex-direction:column;
    align-items:stretch;
    justify-content:flex-start;
    gap:1.25rem;
    padding:calc(var(--header-h-compact) + 1.25rem) clamp(18px,5vw,26px) 2rem;
    background:var(--ink-900);
    border-right:1px solid var(--ink-700);
    overflow-y:auto;
    transform:translateX(-102%);
    transition:transform .24s var(--ease);
  }
  .site-header[data-open="true"] .nav{transform:translateX(0)}
  .nav__list{flex-direction:column;align-items:stretch;gap:0;width:100%}
  .nav__item{border-bottom:1px solid var(--ink-700)}
  .nav__link{display:block;padding:.85rem 0;font-size:1rem}
  .nav__link::after{left:0;bottom:.55rem}
  .nav__link:hover::after{width:32px}
  .nav__link[aria-current="page"]::after{width:26px}
  .nav__cta{margin-left:0;text-align:center;padding:.7rem 1rem;font-size:.85rem}
  body.is-nav-open{overflow:hidden}
}

@media (max-width:640px){
  .grid--trio,.grid--2{grid-template-columns:minmax(0,1fr)}
  .footer-grid{grid-template-columns:minmax(0,1fr);gap:28px}
  .brand__line{display:none}
  .index-band{grid-auto-columns:minmax(210px,1fr)}
  .section-head__note{max-width:none}
}

@media (max-width:380px){
  .brand__mark{width:34px;height:34px;font-size:1.3rem}
  .nav__toggle-text{display:none}
}

/* ---------- 17. 动效偏好 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  .btn:hover,.to-top{transform:none}
}