/* ============================================================
   /assets/site.css — 共享外壳：reset、变量、排版、页头、页脚、
   通用按钮、面包屑、容器、网格、基础组件
   ============================================================ */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:132px}
body,h1,h2,h3,h4,h5,p,ul,ol,li,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}
:focus-visible{outline:2px solid var(--gold-soft);outline-offset:3px;border-radius:2px}
::selection{background:rgba(230,180,92,.3);color:#fff}

/* ---------- 2. Tokens ---------- */
:root{
  --ink:#07111F;
  --ink-2:#0D1A2E;
  --ink-3:#172A45;
  --deep:#050C16;
  --gold:#E6B45C;
  --gold-soft:#F3D08A;
  --celadon:#63C79B;
  --clay:#D9824C;
  --paper:#F2E8D5;
  --text:#F2F6FC;
  --muted:#A7B5C9;
  --line:#2A3B55;
  --line-strong:#3C5175;
  --wrap:1180px;
  --pad:clamp(16px,4vw,40px);
  --radius:3px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --shadow:0 20px 44px -24px rgba(0,0,0,.92);
  --sans:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --mono:"IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,"Courier New",monospace;
}

/* ---------- 3. Base / 中文排版 ---------- */
body{
  min-height:100vh;
  color:var(--text);
  font-family:var(--sans);
  font-size:clamp(15px,.35vw + 14px,17px);
  line-height:1.8;
  letter-spacing:.01em;
  background-color:var(--ink);
  background-image:
    radial-gradient(1100px 640px at 86% -14%, rgba(230,180,92,.11), transparent 60%),
    radial-gradient(780px 520px at 2% 6%, rgba(99,199,155,.075), transparent 58%),
    repeating-linear-gradient(0deg, rgba(42,59,85,.26) 0 1px, transparent 1px 76px),
    repeating-linear-gradient(90deg, rgba(42,59,85,.18) 0 1px, transparent 1px 76px);
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{font-family:var(--sans);font-weight:700;line-height:1.26;letter-spacing:-.012em;color:var(--text)}
h1{font-size:clamp(2.05rem,4.4vw,3.35rem);letter-spacing:-.024em}
h2{font-size:clamp(1.45rem,2.4vw,2rem)}
h3{font-size:clamp(1.1rem,1.5vw,1.32rem);font-weight:600}
h4{font-size:1rem;font-weight:600}
p{max-width:72ch}
strong{font-weight:600;color:var(--text)}

/* ---------- 4. 布局工具 ---------- */
.wrap{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:var(--pad)}
.section{padding-block:clamp(46px,6.6vw,92px)}
.section-head{display:grid;gap:14px;max-width:70ch}
.eyebrow{display:inline-flex;align-items:center;gap:9px;font-family:var(--mono);font-size:11px;letter-spacing:.16em;text-transform:uppercase;color:var(--gold-soft)}
.eyebrow::before{content:"";width:24px;height:1px;background:linear-gradient(90deg,var(--gold),rgba(230,180,92,0))}
.idx{font-family:var(--mono);font-size:clamp(1.9rem,4.6vw,3rem);line-height:1;color:var(--line-strong);font-variant-numeric:tabular-nums;letter-spacing:-.02em}
.lede{font-size:clamp(1rem,1.1vw,1.125rem);line-height:1.85;color:var(--muted);max-width:62ch}
.mono{font-family:var(--mono);font-size:12px;letter-spacing:.08em;font-variant-numeric:tabular-nums}
.text-muted{color:var(--muted)}
.flow > * + *{margin-top:var(--flow,1.1rem)}
.grid{display:grid;gap:clamp(16px,2.4vw,28px)}
.grid--2{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.grid--3{grid-template-columns:repeat(auto-fit,minmax(232px,1fr))}
.grid--sidebar{grid-template-columns:minmax(0,1fr)}
@media (min-width:900px){.grid--sidebar{grid-template-columns:minmax(0,1fr) 280px;align-items:start}}

/* ---------- 5. Skip link ---------- */
.skip-link{
  position:fixed;top:10px;left:10px;z-index:200;
  transform:translateY(-180%);
  background:var(--gold);color:#07111F;
  font-family:var(--mono);font-size:12px;letter-spacing:.08em;
  padding:10px 18px;border-radius:2px;
  transition:transform .18s var(--ease);
}
.skip-link:focus,.skip-link:focus-visible{transform:none;outline-offset:2px}

/* ---------- 6. 页头 ---------- */
.site-header{
  position:sticky;top:0;z-index:60;
  background:rgba(7,17,31,.97);
  border-bottom:1px solid var(--line);
  -webkit-backdrop-filter:blur(10px);
  backdrop-filter:blur(10px);
}
.progress-bar{position:absolute;left:0;right:0;bottom:-1px;height:2px;z-index:3;background:rgba(42,59,85,.55);pointer-events:none}
.progress-bar__fill{
  display:block;height:100%;width:100%;
  transform:scaleX(0);transform-origin:0 50%;
  background:linear-gradient(90deg,var(--celadon) 0%,var(--gold) 62%,var(--gold-soft) 100%);
  transition:transform .1s linear;
}

.header-rail{background:rgba(4,10,18,.82);border-bottom:1px solid rgba(42,59,85,.7)}
.header-rail__inner{
  display:flex;align-items:center;justify-content:space-between;gap:14px;
  min-height:38px;padding-block:4px;
  font-family:var(--mono);font-size:11px;letter-spacing:.1em;color:var(--muted);
}
.rail-status{display:inline-flex;align-items:center;gap:9px;white-space:nowrap;color:var(--muted)}
.dot{
  display:inline-block;flex:none;width:7px;height:7px;border-radius:50%;
  background:var(--celadon);
  box-shadow:0 0 0 3px rgba(99,199,155,.16),0 0 10px rgba(99,199,155,.55);
}
.rail-index{
  min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;
  color:var(--line-strong);letter-spacing:.14em;
}
.rail-cta{
  white-space:nowrap;color:var(--gold);
  border-bottom:1px solid rgba(230,180,92,.35);padding-bottom:1px;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.rail-cta:hover{color:var(--gold-soft);border-bottom-color:var(--gold-soft)}

.header-main{position:relative}
.header-main__inner{
  display:flex;align-items:center;justify-content:space-between;gap:20px;
  min-height:78px;padding-block:12px;
}

.brand{display:inline-flex;align-items:center;gap:12px;flex:none;min-width:0}
.brand__glyph{
  display:grid;place-items:center;flex:none;
  width:38px;height:38px;color:var(--gold);
  background:var(--ink-3);border:1px solid var(--line);border-radius:2px;
  box-shadow:3px 3px 0 rgba(230,180,92,.16);
  transition:box-shadow .2s var(--ease),transform .2s var(--ease);
}
.brand:hover .brand__glyph{transform:translateY(-1px);box-shadow:0 0 0 1px rgba(230,180,92,.45),3px 3px 0 rgba(230,180,92,.3)}
.brand__text{display:flex;flex-direction:column;gap:2px;min-width:0}
.brand__name{font-size:17px;font-weight:700;line-height:1.2;letter-spacing:.012em;color:var(--text);white-space:nowrap}
.brand__sub{font-family:var(--mono);font-size:10px;line-height:1.3;letter-spacing:.14em;color:var(--muted);text-transform:uppercase;white-space:nowrap}

.nav-toggle{
  display:none;align-items:center;gap:10px;
  padding:9px 14px;border:1px solid var(--line);border-radius:2px;
  background:var(--ink-2);color:var(--text);
  font-family:var(--mono);font-size:12px;letter-spacing:.12em;cursor:pointer;
  transition:border-color .18s var(--ease),color .18s var(--ease),background .18s var(--ease);
}
.nav-toggle:hover{border-color:rgba(230,180,92,.65);color:var(--gold-soft)}
.nav-toggle__bars{display:inline-flex;flex-direction:column;justify-content:space-between;width:16px;height:11px}
.nav-toggle__bars span{display:block;height:1.5px;background:currentColor;transition:transform .2s var(--ease),opacity .2s var(--ease)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1){transform:translateY(4.75px) 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(-4.75px) rotate(-45deg)}
.nav-toggle__text{white-space:nowrap}

.site-nav{display:block}
.site-nav__list{display:flex;align-items:center;justify-content:flex-end;flex-wrap:wrap;gap:4px}
.site-nav__item{flex:none}
.site-nav__link{
  position:relative;display:block;padding:9px 12px;border:1px solid transparent;border-radius:2px;
  font-size:14px;line-height:1.3;color:var(--muted);white-space:nowrap;
  transition:color .18s var(--ease),background .18s var(--ease),border-color .18s var(--ease),box-shadow .18s var(--ease);
}
.site-nav__link::before{
  content:attr(data-index);
  font-family:var(--mono);font-size:10px;letter-spacing:.08em;
  color:var(--line-strong);margin-right:6px;vertical-align:1px;
  transition:color .18s var(--ease);
}
.site-nav__link:hover{color:var(--text);background:var(--ink-2);border-color:var(--line)}
.site-nav__link:hover::before{color:var(--gold)}
.site-nav__link[aria-current="page"]{
  color:var(--gold-soft);
  background:rgba(230,180,92,.1);
  border-color:rgba(230,180,92,.45);
  box-shadow:inset 0 -2px 0 var(--gold);
}
.site-nav__link[aria-current="page"]::before{color:var(--celadon)}

/* ---------- 7. 页脚 ---------- */
.site-footer{
  position:relative;
  background:linear-gradient(180deg,#08131F 0%,var(--deep) 100%);
  border-top:1px solid var(--line);
  color:var(--muted);
}
.site-footer::before{
  content:"";display:block;height:2px;
  background:linear-gradient(90deg,var(--gold) 0%,rgba(230,180,92,.12) 46%,rgba(99,199,155,.6) 100%);
}
.footer-inner{
  display:grid;
  grid-template-columns:1.5fr .85fr 1.25fr;
  gap:clamp(28px,4vw,56px);
  padding-block:clamp(36px,5.4vw,68px);
}
.footer-brand__kicker{
  display:inline-flex;align-items:center;gap:9px;
  margin-bottom:14px;
  font-family:var(--mono);font-size:11px;letter-spacing:.16em;text-transform:uppercase;color:var(--gold);
}
.footer-brand__kicker::before{content:"";width:20px;height:1px;background:var(--gold)}
.footer-brand__name{font-size:clamp(1.15rem,2vw,1.4rem);font-weight:700;color:var(--text);letter-spacing:.01em;line-height:1.35}
.footer-brand__line{margin-top:10px;max-width:28ch;font-size:14px;line-height:1.8;color:var(--muted)}
.footer-brand__cta{
  display:inline-flex;align-items:center;gap:8px;margin-top:18px;
  font-family:var(--mono);font-size:12px;letter-spacing:.1em;color:var(--gold);
  border-bottom:1px solid rgba(230,180,92,.4);padding-bottom:3px;
  transition:color .18s var(--ease),border-color .18s var(--ease),gap .18s var(--ease);
}
.footer-brand__cta:hover{color:var(--gold-soft);border-bottom-color:var(--gold-soft);gap:13px}

.footer-col{min-width:0}
.footer-col__title{
  display:flex;align-items:center;gap:9px;
  margin-bottom:16px;
  font-family:var(--mono);font-size:11px;font-weight:500;letter-spacing:.16em;text-transform:uppercase;color:var(--gold-soft);
}
.footer-col__title::before{content:"";width:2px;height:12px;background:var(--gold);flex:none}
.footer-list{display:grid;gap:10px;font-size:14px}
.footer-link{
  display:inline-block;color:var(--muted);
  border-bottom:1px solid transparent;padding-bottom:1px;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.footer-link:hover{color:var(--gold-soft);border-bottom-color:rgba(230,180,92,.55)}

.footer-fact{display:flex;flex-wrap:wrap;align-items:baseline;gap:4px 10px}
.footer-fact__key{
  flex:none;min-width:36px;
  font-family:var(--mono);font-size:10px;letter-spacing:.14em;text-transform:uppercase;color:var(--line-strong);
}
.footer-fact__val{font-size:13.5px;line-height:1.65;color:var(--text);word-break:break-word}
.copy-btn{
  flex:none;cursor:pointer;appearance:none;
  padding:3px 9px;border:1px solid var(--line);border-radius:2px;
  background:rgba(23,42,69,.85);color:var(--muted);
  font-family:var(--mono);font-size:11px;letter-spacing:.08em;
  transition:color .18s var(--ease),border-color .18s var(--ease),background .18s var(--ease);
}
.copy-btn:hover{color:var(--gold-soft);border-color:rgba(230,180,92,.6);background:rgba(230,180,92,.1)}
.copy-status{
  margin-top:12px;min-height:1.5em;
  font-family:var(--mono);font-size:11px;letter-spacing:.04em;line-height:1.5;color:var(--celadon);
}
.copy-status:empty{display:none}
.footer-note{
  margin-top:16px;padding-left:11px;
  border-left:1px solid var(--line);
  font-size:12.5px;line-height:1.75;color:var(--line-strong);
}

.footer-base{border-top:1px solid rgba(42,59,85,.85);background:rgba(3,8,15,.72)}
.footer-base__inner{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px 28px;
  padding-block:18px;
  font-family:var(--mono);font-size:11.5px;letter-spacing:.06em;color:var(--line-strong);
}
.footer-legal{display:flex;flex-wrap:wrap;align-items:center;gap:6px 18px}
.footer-legal__link{
  color:var(--muted);padding-bottom:2px;border-bottom:1px solid transparent;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.footer-legal__link:hover{color:var(--gold-soft);border-bottom-color:rgba(230,180,92,.6)}
.footer-meta{display:flex;flex-wrap:wrap;align-items:center;gap:4px 18px}
.footer-meta__item{white-space:nowrap}

/* ---------- 8. 通用按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:9px;
  padding:12px 22px;border:1px solid transparent;border-radius:2px;
  font-size:14px;font-weight:600;line-height:1.4;letter-spacing:.01em;
  cursor:pointer;
  transition:background .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease),transform .18s var(--ease),box-shadow .18s var(--ease);
}
.btn--primary{background:var(--gold);color:#08131F;border-color:var(--gold);box-shadow:0 10px 24px -14px rgba(230,180,92,.9)}
.btn--primary:hover{background:var(--gold-soft);border-color:var(--gold-soft);transform:translateY(-1px)}
.btn--ghost{background:transparent;color:var(--text);border-color:var(--line)}
.btn--ghost:hover{color:var(--gold-soft);border-color:rgba(230,180,92,.6);background:rgba(230,180,92,.08)}
.btn--quiet{padding:4px 0;color:var(--gold);border:0;border-bottom:1px solid rgba(230,180,92,.45);border-radius:0}
.btn--quiet:hover{color:var(--gold-soft);border-bottom-color:var(--gold-soft)}

/* ---------- 9. 标签 ---------- */
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 9px;border:1px solid var(--line);border-radius:2px;
  background:rgba(23,42,69,.6);color:var(--muted);
  font-family:var(--mono);font-size:11px;line-height:1.5;letter-spacing:.1em;text-transform:uppercase;
  white-space:nowrap;
}
.tag--gold{color:var(--gold-soft);border-color:rgba(230,180,92,.55);background:rgba(230,180,92,.1)}
.tag--celadon{color:var(--celadon);border-color:rgba(99,199,155,.5);background:rgba(99,199,155,.1)}
.tag--clay{color:var(--clay);border-color:rgba(217,130,76,.5);background:rgba(217,130,76,.1)}
.tag--paper{color:#16202F;background:var(--paper);border-color:var(--paper)}

/* ---------- 10. 面板与卡片 ---------- */
.panel{
  position:relative;
  padding:clamp(20px,3vw,34px);
  background:var(--ink-2);border:1px solid var(--line);border-radius:var(--radius);
}
.panel--paper{background:var(--paper);color:#16202F;border-color:rgba(230,180,92,.55)}
.panel--paper h2,.panel--paper h3,.panel--paper h4,.panel--paper strong{color:#101A29}
.panel--paper .lede,.panel--paper p{color:#3C4959}
.panel--paper .idx{color:rgba(22,32,47,.28)}

.card{
  position:relative;
  padding:clamp(18px,2.2vw,26px);
  background:linear-gradient(180deg,var(--ink-2) 0%,rgba(13,26,46,.72) 100%);
  border:1px solid var(--line);border-radius:var(--radius);
  transition:transform .18s var(--ease),border-color .18s var(--ease),box-shadow .18s var(--ease);
}
.card:hover{transform:translateY(-3px);border-color:var(--line-strong);box-shadow:var(--shadow)}
.card-grid{display:grid;gap:clamp(14px,2vw,22px);grid-template-columns:repeat(auto-fit,minmax(248px,1fr))}

/* ---------- 11. 可复用图片容器 ---------- */
.media-frame{
  position:relative;display:grid;place-items:center;overflow:hidden;
  aspect-ratio:16/9;border:1px solid var(--line);border-radius:var(--radius);
  background:linear-gradient(160deg,rgba(23,42,69,.95) 0%,rgba(7,17,31,.98) 100%);
}
.media-frame::before{
  content:"";position:absolute;inset:0;
  background-image:
    repeating-linear-gradient(0deg,rgba(42,59,85,.55) 0 1px,transparent 1px 40px),
    repeating-linear-gradient(90deg,rgba(42,59,85,.4) 0 1px,transparent 1px 40px);
  opacity:.75;
}
.media-frame::after{
  content:"";position:absolute;left:7%;right:7%;top:50%;height:1px;
  background:linear-gradient(90deg,rgba(230,180,92,0),var(--gold),rgba(230,180,92,0));
  opacity:.6;
}
.media-frame > img{position:relative;z-index:1;width:100%;height:100%;object-fit:cover}
.media-frame__note{
  position:relative;z-index:1;
  padding:5px 10px;border:1px solid var(--line);border-radius:2px;
  background:rgba(7,17,31,.78);
  font-family:var(--mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase;color:var(--muted);
}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--tall{aspect-ratio:4/5}
.media-frame--square{aspect-ratio:1/1}

/* ---------- 12. 面包屑 ---------- */
.breadcrumbs{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--mono);font-size:12px;letter-spacing:.06em;color:var(--muted);
}
.breadcrumbs__item{display:inline-flex;align-items:center;gap:8px;min-width:0}
.breadcrumbs__item + .breadcrumbs__item::before{content:"/";color:var(--line-strong)}
.breadcrumbs__link{color:var(--muted);border-bottom:1px solid transparent;transition:color .18s var(--ease),border-color .18s var(--ease)}
.breadcrumbs__link:hover{color:var(--gold-soft);border-bottom-color:rgba(230,180,92,.55)}
.breadcrumbs [aria-current="page"]{color:var(--text)}

/* ---------- 13. 长文排版 ---------- */
.prose{max-width:74ch;font-size:1rem;line-height:1.92;color:var(--muted)}
.prose > * + *{margin-top:1.1em}
.prose h2{color:var(--text);margin-top:2em;font-size:clamp(1.25rem,2vw,1.55rem)}
.prose h3{color:var(--text);margin-top:1.6em}
.prose ul,.prose ol{display:grid;gap:.55em}
.prose ul li{position:relative;padding-left:1.15em}
.prose ul li::before{content:"";position:absolute;left:0;top:.78em;width:9px;height:1px;background:var(--gold)}
.prose ol{counter-reset:prose;padding-left:1.4em;list-style:decimal}
.prose ol li::marker{color:var(--gold);font-family:var(--mono);font-size:.85em}
.prose blockquote{
  padding:18px 22px;border-left:3px solid var(--gold);border-radius:2px;
  background:var(--paper);color:#1B2634;font-size:.95rem;line-height:1.85;
}
.prose code{
  padding:2px 6px;border-radius:2px;background:var(--ink-3);
  font-family:var(--mono);font-size:.85em;color:var(--gold-soft);
}
.prose a{color:var(--gold);border-bottom:1px solid rgba(230,180,92,.45)}
.prose a:hover{color:var(--gold-soft);border-bottom-color:var(--gold-soft)}

/* ---------- 14. 分段切换 Tabs ---------- */
.tabs{display:block}
.tabs__list{
  display:flex;flex-wrap:wrap;gap:6px;
  padding:6px;border:1px solid var(--line);border-radius:var(--radius);background:var(--ink-2);
}
.tabs__btn{
  appearance:none;cursor:pointer;
  padding:9px 16px;border:1px solid transparent;border-radius:2px;
  background:transparent;color:var(--muted);
  font-size:14px;font-weight:600;line-height:1.4;letter-spacing:.01em;
  transition:color .18s var(--ease),background .18s var(--ease),border-color .18s var(--ease),box-shadow .18s var(--ease);
}
.tabs__btn:hover{color:var(--text);background:rgba(23,42,69,.9);border-color:var(--line)}
.tabs__btn[aria-selected="true"]{
  color:var(--gold-soft);background:rgba(230,180,92,.12);
  border-color:rgba(230,180,92,.5);box-shadow:inset 0 -2px 0 var(--gold);
}
.tabs__panel{padding-top:clamp(18px,2.4vw,26px)}
.tabs__panel[hidden]{display:none}

/* ---------- 15. 入场显现 ---------- */
.reveal{
  opacity:0;transform:translateY(14px);
  transition:opacity .5s var(--ease),transform .5s var(--ease);
  transition-delay:calc(var(--i,0) * 60ms);
}
.reveal.is-in{opacity:1;transform:none}

/* ---------- 16. 动效关键帧 ---------- */
@keyframes navDrop{
  from{opacity:0;transform:translateY(-8px)}
  to{opacity:1;transform:none}
}

/* ---------- 17. 响应式 ---------- */
@media (max-width:1100px){
  .rail-index{display:none}
  .site-nav__link{font-size:13.5px;padding:9px 10px}
}
@media (max-width:960px){
  html{scroll-padding-top:120px}
  .nav-toggle{display:inline-flex}
  .header-main__inner{min-height:70px;flex-wrap:nowrap}
  .site-nav{
    position:absolute;left:0;right:0;top:100%;z-index:5;
    display:none;
    padding:8px var(--pad) 22px;
    background:var(--ink-2);
    border-top:1px solid var(--line);
    border-bottom:1px solid var(--line);
    box-shadow:0 32px 60px -24px rgba(0,0,0,.92);
  }
  .site-nav[data-open]{display:block;animation:navDrop .22s var(--ease)}
  .site-nav__list{flex-direction:column;align-items:stretch;gap:0}
  .site-nav__item + .site-nav__item{border-top:1px dashed rgba(42,59,85,.85)}
  .site-nav__link{padding:14px 4px;font-size:16px;border:1px solid transparent}
  .site-nav__link[aria-current="page"]{border-color:rgba(230,180,92,.4)}
  .site-nav__link::before{font-size:11px;margin-right:9px}
  .footer-inner{grid-template-columns:1fr 1fr}
  .footer-brand{grid-column:1 / -1}
  .footer-brand__line{max-width:44ch}
}
@media (max-width:820px){
  .rail-status{font-size:10.5px;letter-spacing:.08em}
  .rail-cta{font-size:10.5px}
}
@media (max-width:560px){
  .header-main__inner{gap:12px}
  .brand__sub{display:none}
  .brand__name{font-size:15.5px}
  .brand__glyph{width:34px;height:34px}
  .nav-toggle{padding:8px 11px;font-size:11px;letter-spacing:.08em}
  .footer-inner{grid-template-columns:1fr;gap:30px}
  .footer-base__inner{justify-content:flex-start;font-size:11px}
  .footer-meta{gap:2px 14px}
  .btn{padding:11px 18px;font-size:13.5px}
}

/* ---------- 18. 无障碍偏好 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .reveal{opacity:1;transform:none}
  .card:hover{transform:none}
  .btn--primary:hover{transform:none}
  .brand:hover .brand__glyph{transform:none}
  .site-nav[data-open]{animation:none}
}