/* ==========================================================================
   快盈3中文站 · 共享样式表 /assets/site.css
   深墨蓝底 + 精密网格 + 电光青/暖金双强调的档案式信息系统
   ========================================================================== */

/* ---------- 1. 令牌 ---------- */
:root{
  --ink-abyss:#0A1626;
  --navy-deck:#122741;
  --grid-line:#1E3A5C;
  --electric-cyan:#1FE0E8;
  --teal-deep:#0E8C99;
  --warm-gold:#E8B44A;
  --gold-pale:#F4D699;
  --cream-paper:#F2ECDF;
  --slate-mist:#A9BED2;
  --muted-ink:#5C7A99;
  --signal-rust:#D2603A;

  --font-display:"Archivo Narrow","Oswald","Noto Sans SC","PingFang SC","Microsoft YaHei",sans-serif;
  --font-body:"Inter","Noto Sans SC",system-ui,-apple-system,"Segoe UI","Microsoft YaHei",sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --ease:cubic-bezier(.22,.61,.36,1);
  --shell:1240px;
  --edge:clamp(1.125rem,4vw,3rem);
  --gap:clamp(1rem,2.2vw,2rem);
}

/* ---------- 2. 重置与基础 ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;}
@media (prefers-reduced-motion: no-preference){html{scroll-behavior:smooth;}}
body,h1,h2,h3,h4,h5,p,ul,ol,figure,blockquote,dl,dd{margin:0;}
img,svg,video{display:block;max-width:100%;}
button,input,select,textarea{font:inherit;color:inherit;}
[hidden]{display:none !important;}
:focus-visible{outline:2px solid var(--electric-cyan);outline-offset:2px;}
::selection{background:var(--electric-cyan);color:var(--ink-abyss);}

body{
  background-color:var(--ink-abyss);
  background-image:
    linear-gradient(to right, rgba(30,58,92,.42) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30,58,92,.42) 1px, transparent 1px);
  background-size:76px 76px;
  color:var(--cream-paper);
  font-family:var(--font-body);
  font-size:clamp(1rem,0.35vw + 0.94rem,1.0625rem);
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}

h1,h2,h3,h4{
  font-family:var(--font-display);
  font-weight:700;
  letter-spacing:-.01em;
  line-height:1.15;
  color:var(--cream-paper);
}
h1{font-size:clamp(2.4rem,5vw,4.2rem);}
h2{font-size:clamp(1.45rem,2.6vw,2.1rem);}
h3{font-size:1.2rem;}
p{max-width:72ch;}
a{color:var(--electric-cyan);text-underline-offset:3px;text-decoration-thickness:1px;}
strong{font-weight:600;color:var(--cream-paper);}
.mono,.num{font-family:var(--font-mono);font-weight:700;font-variant-numeric:tabular-nums;}
.visually-hidden{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0;}
.rule{height:1px;background:var(--grid-line);border:0;}

/* ---------- 3. 布局 ---------- */
.container{width:100%;max-width:var(--shell);margin-inline:auto;padding-inline:var(--edge);}
#main-content{display:block;scroll-margin-top:132px;}

.layout-grid{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:var(--gap);}
.col-2{grid-column:span 2;}
.col-3{grid-column:span 3;}
.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-9{grid-column:span 9;}
.col-10{grid-column:span 10;}
.col-12{grid-column:span 12;}

.section{position:relative;padding-block:clamp(2.25rem,5vw,4rem);}
.section__head{
  display:flex;align-items:baseline;gap:.75rem;flex-wrap:wrap;
  padding-bottom:.7rem;margin-bottom:clamp(1rem,2.4vw,1.75rem);
  border-bottom:1px solid var(--grid-line);
}
.section__index{font-family:var(--font-mono);font-size:.75rem;font-weight:700;letter-spacing:.14em;color:var(--electric-cyan);}
.section__title{font-family:var(--font-display);font-size:clamp(1.3rem,2.4vw,1.9rem);line-height:1.2;}
.section__meta{margin-left:auto;font-family:var(--font-mono);font-size:.75rem;color:var(--muted-ink);}
.eyebrow{display:inline-block;font-family:var(--font-mono);font-size:.6875rem;font-weight:700;letter-spacing:.18em;text-transform:uppercase;color:var(--warm-gold);}

/* ---------- 4. 刊头 ---------- */
.skip-link{
  position:fixed;left:50%;top:-120px;transform:translateX(-50%);z-index:200;
  padding:.6rem 1.15rem;background:var(--electric-cyan);color:var(--ink-abyss);
  font-family:var(--font-mono);font-size:.8125rem;font-weight:700;text-decoration:none;
  transition:top .2s var(--ease);
}
.skip-link:focus{top:.6rem;}

.masthead{
  position:sticky;top:0;z-index:60;
  background:rgba(10,22,38,.94);
  -webkit-backdrop-filter:saturate(140%) blur(10px);
  backdrop-filter:saturate(140%) blur(10px);
  border-bottom:1px solid var(--grid-line);
  transition:background-color .24s var(--ease),box-shadow .24s var(--ease);
}
.masthead::before{
  content:"";position:absolute;top:0;left:0;bottom:0;width:min(30%,340px);
  background:linear-gradient(90deg, rgba(31,224,232,.16), rgba(31,224,232,0));
  clip-path:polygon(0 0,100% 0,76% 100%,0 100%);
  pointer-events:none;
}
.masthead[data-stuck]{background:rgba(10,22,38,.99);box-shadow:0 14px 34px -26px rgba(0,0,0,.95);}
.masthead[data-stuck] .masthead__status{display:none;}
.masthead[data-stuck] .masthead__brand-mark{font-size:1.4rem;}
.masthead[data-stuck] .masthead__top{padding-block:.45rem .3rem;}

.scroll-progress{position:absolute;left:0;right:0;bottom:-1px;height:2px;overflow:hidden;pointer-events:none;}
.scroll-progress__bar{
  display:block;width:100%;height:100%;transform:scaleX(0);transform-origin:left center;
  background:linear-gradient(90deg,var(--electric-cyan),var(--warm-gold));
  transition:transform .1s linear;
}

.masthead__inner{position:relative;}
.masthead__top{
  display:grid;grid-template-columns:minmax(0,1fr) auto minmax(0,1fr);
  align-items:center;gap:1rem;padding-block:.85rem .55rem;
}

.chip-row{display:flex;flex-wrap:wrap;align-items:center;gap:.4rem;list-style:none;padding:0;}
.chip{
  display:inline-flex;align-items:center;gap:.4rem;padding:.25rem .55rem;
  border:1px solid var(--grid-line);background:rgba(18,39,65,.6);
  color:var(--slate-mist);font-size:.75rem;letter-spacing:.02em;white-space:nowrap;
}
.chip::before{content:"";width:6px;height:6px;flex:0 0 auto;background:var(--teal-deep);}
.chip--gold{border-color:rgba(232,180,74,.5);color:var(--gold-pale);}
.chip--gold::before{background:var(--warm-gold);}
.masthead__status{min-width:0;}

.masthead__brand{
  grid-column:2;justify-self:center;display:flex;align-items:baseline;gap:.55rem;
  text-decoration:none;color:var(--cream-paper);
}
.masthead__brand-mark{
  font-family:var(--font-display);font-weight:700;line-height:1;
  font-size:clamp(1.5rem,3.2vw,2.2rem);letter-spacing:.06em;
  transition:color .18s var(--ease),font-size .2s var(--ease);
}
.masthead__brand-suffix{
  font-family:var(--font-mono);font-size:.6875rem;font-weight:700;letter-spacing:.26em;
  color:var(--electric-cyan);padding-left:.55rem;border-left:1px solid var(--grid-line);
}
.masthead__brand:hover .masthead__brand-mark{color:var(--electric-cyan);}

.masthead__tools{justify-self:end;display:flex;align-items:center;gap:.5rem;}
.quick-links{display:flex;align-items:center;gap:.35rem;list-style:none;padding:0;}
.quick-link{
  display:inline-flex;align-items:center;min-height:44px;padding:0 .7rem;
  border:1px solid transparent;color:var(--slate-mist);font-size:.8125rem;text-decoration:none;
  transition:color .18s var(--ease),border-color .18s var(--ease),background-color .18s var(--ease);
}
.quick-link:hover,.quick-link:focus-visible{color:var(--cream-paper);border-color:var(--electric-cyan);background:rgba(31,224,232,.08);}
.quick-link--key{background:var(--electric-cyan);border-color:var(--electric-cyan);color:var(--ink-abyss);font-weight:600;}
.quick-link--key:hover,.quick-link--key:focus-visible{background:var(--warm-gold);border-color:var(--warm-gold);color:var(--ink-abyss);}

.nav-toggle{
  display:none;align-items:center;gap:.55rem;min-height:44px;padding:0 .7rem;
  background:transparent;border:1px solid var(--grid-line);color:var(--cream-paper);
  font-family:var(--font-mono);font-size:.75rem;font-weight:700;letter-spacing:.1em;cursor:pointer;
  transition:border-color .18s var(--ease),color .18s var(--ease);
}
.nav-toggle:hover{border-color:var(--electric-cyan);color:var(--electric-cyan);}
.nav-toggle__bars{display:grid;gap:3px;width:16px;}
.nav-toggle__bars span{display:block;height:2px;background:currentColor;}
.nav-toggle__text{white-space:nowrap;}

.nav{display:flex;align-items:center;gap:1rem;border-top:1px solid var(--grid-line);}
.nav__list{
  display:flex;align-items:stretch;flex:1 1 auto;justify-content:center;
  list-style:none;padding:0;overflow-x:auto;scrollbar-width:none;
}
.nav__list::-webkit-scrollbar{height:0;}
.nav__item{flex:0 0 auto;}
.nav__link{
  position:relative;display:inline-flex;align-items:center;gap:.5rem;
  min-height:46px;padding:0 clamp(.7rem,1.4vw,1.15rem);
  color:var(--slate-mist);font-size:.9375rem;font-weight:500;text-decoration:none;
  transition:color .18s var(--ease);
}
.nav__link:hover{color:var(--cream-paper);}
.nav__link::after{content:"";position:absolute;left:.5rem;right:.5rem;bottom:0;height:2px;background:transparent;transition:background-color .18s var(--ease);}
.nav__link:hover::after{background:var(--grid-line);}
.nav__link[aria-current="page"]{color:var(--cream-paper);}
.nav__link[aria-current="page"]::after{background:var(--electric-cyan);}
.nav__index{font-family:var(--font-mono);font-size:.6875rem;font-weight:700;letter-spacing:.04em;color:var(--teal-deep);}
.nav__link[aria-current="page"] .nav__index{color:var(--electric-cyan);}
.nav__note{flex:0 0 auto;max-width:26ch;padding-block:.4rem;font-size:.6875rem;line-height:1.5;color:var(--muted-ink);text-align:right;}

/* ---------- 5. 页脚 ---------- */
.site-footer{
  position:relative;margin-top:clamp(2.5rem,6vw,5rem);
  padding:clamp(2rem,4vw,3.25rem) 0 1.25rem;
  background:linear-gradient(180deg,#0D1C30,var(--ink-abyss));
  border-top:1px solid var(--grid-line);
  color:var(--slate-mist);
}
.site-footer::before{
  content:"";position:absolute;top:-1px;left:0;width:min(38%,420px);height:3px;
  background:linear-gradient(90deg,var(--electric-cyan),var(--warm-gold));
}
.footer__grid{display:grid;grid-template-columns:1.4fr 2.1fr 1.5fr;gap:var(--gap);}
.footer__col{min-width:0;}
.footer__brandcol{display:grid;gap:.85rem;align-content:start;}
.footer__brand{display:inline-flex;align-items:baseline;gap:.5rem;text-decoration:none;color:var(--cream-paper);}
.footer__brand-mark{font-family:var(--font-display);font-weight:700;font-size:1.5rem;line-height:1;letter-spacing:.06em;}
.footer__brand-suffix{font-family:var(--font-mono);font-size:.6875rem;font-weight:700;letter-spacing:.24em;color:var(--electric-cyan);}
.footer__brand:hover .footer__brand-mark{color:var(--electric-cyan);}
.footer__intro{max-width:34ch;font-size:.9375rem;line-height:1.75;color:var(--slate-mist);}
.footer__trust{
  max-width:34ch;padding-left:.7rem;border-left:2px solid var(--warm-gold);
  font-family:var(--font-mono);font-size:.6875rem;line-height:1.6;color:var(--gold-pale);
}
.footer__cols{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1rem;}
.footer__col-title{
  font-family:var(--font-mono);font-size:.6875rem;font-weight:700;letter-spacing:.18em;
  color:var(--warm-gold);margin-bottom:.6rem;
}
.footer__links{list-style:none;padding:0;display:grid;}
.footer__links a{
  display:inline-flex;align-items:center;min-height:44px;
  color:var(--slate-mist);font-size:.9rem;text-decoration:none;
  transition:color .18s var(--ease);
}
.footer__links a:hover,.footer__links a:focus-visible{color:var(--electric-cyan);}
.footer__contact{display:grid;gap:.35rem;align-content:start;}
.footer__contact-row{
  display:grid;grid-template-columns:5.5rem minmax(0,1fr);
  gap:.2rem .6rem;align-items:center;max-width:none;
}
.footer__contact-label{font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.08em;color:var(--muted-ink);}
.footer__mono{font-family:var(--font-mono);font-size:.8125rem;font-weight:700;line-height:1.5;color:var(--cream-paper);word-break:break-all;}
.footer__baseline{
  display:flex;flex-wrap:wrap;gap:.75rem 1.5rem;justify-content:space-between;align-items:center;
  margin-top:clamp(1.5rem,3vw,2.5rem);padding-top:1rem;
  border-top:1px solid var(--grid-line);
  font-size:.75rem;color:var(--muted-ink);
}
.footer__legal{font-family:var(--font-mono);letter-spacing:.04em;color:var(--slate-mist);}
.footer__meta{font-family:var(--font-mono);letter-spacing:.02em;}

/* ---------- 6. 通用组件 ---------- */
.panel{position:relative;background:var(--navy-deck);border:1px solid var(--grid-line);padding:clamp(1rem,2vw,1.5rem);}
.panel--deck{background:rgba(18,39,65,.55);}
.panel--flat{background:transparent;}
.panel--paper{background:var(--cream-paper);border-color:#C9BC9C;color:#16222F;}
.panel--paper h2,.panel--paper h3{color:#0A1626;}
.panel--paper p{color:#3B4A59;}
.panel--paper .eyebrow{color:#8A6420;}
.panel--paper a{color:#0B5B64;}

.card{
  position:relative;display:block;background:var(--navy-deck);border:1px solid var(--grid-line);
  padding:clamp(1rem,2vw,1.4rem);text-decoration:none;color:var(--cream-paper);
  transition:transform .22s var(--ease),border-color .22s var(--ease),background-color .22s var(--ease);
}
.card:hover,.card:focus-visible{transform:translate(-4px,-4px);border-color:var(--electric-cyan);background:#16304F;}
.card__title{font-family:var(--font-display);font-size:1.125rem;line-height:1.3;margin-bottom:.35rem;}
.card__meta{font-family:var(--font-mono);font-size:.6875rem;letter-spacing:.04em;color:var(--muted-ink);}

.tag{
  display:inline-flex;align-items:center;gap:.35rem;padding:.2rem .5rem;
  border:1px solid var(--teal-deep);background:rgba(14,140,153,.14);color:var(--electric-cyan);
  font-family:var(--font-mono);font-size:.6875rem;font-weight:700;letter-spacing:.04em;white-space:nowrap;
}
.tag--gold{border-color:var(--warm-gold);background:rgba(232,180,74,.16);color:var(--gold-pale);}
.tag--rust{border-color:var(--signal-rust);background:rgba(210,96,58,.16);color:#F0B79F;}
.tag--plain{border-color:var(--grid-line);background:transparent;color:var(--slate-mist);}

.index-list{list-style:none;padding:0;}
.index-list__item{
  display:grid;grid-template-columns:3.25rem minmax(0,1fr);gap:1rem;
  padding:.9rem 0;border-bottom:1px solid var(--grid-line);
}
.index-list__num{font-family:var(--font-mono);font-size:.8125rem;font-weight:700;letter-spacing:.06em;color:var(--electric-cyan);}

.stat{display:grid;gap:.15rem;}
.stat__value{
  font-family:var(--font-mono);font-weight:700;line-height:1.05;font-variant-numeric:tabular-nums;
  font-size:clamp(1.5rem,3vw,2.25rem);color:var(--cream-paper);
}
.stat__label{font-size:.8125rem;color:var(--slate-mist);}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5rem;
  min-height:44px;padding:0 1.1rem;border:1px solid var(--electric-cyan);
  background:transparent;color:var(--electric-cyan);
  font-family:var(--font-body);font-size:.9rem;font-weight:600;letter-spacing:.02em;
  text-decoration:none;cursor:pointer;
  transition:background-color .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease);
}
.btn:hover,.btn:focus-visible{background:var(--electric-cyan);color:var(--ink-abyss);}
.btn--solid{background:var(--electric-cyan);color:var(--ink-abyss);}
.btn--solid:hover,.btn--solid:focus-visible{background:var(--warm-gold);border-color:var(--warm-gold);color:var(--ink-abyss);}
.btn--gold{border-color:var(--warm-gold);color:var(--gold-pale);}
.btn--gold:hover,.btn--gold:focus-visible{background:var(--warm-gold);color:var(--ink-abyss);}
.btn--ghost{border-color:var(--grid-line);color:var(--slate-mist);}
.btn--ghost:hover,.btn--ghost:focus-visible{background:transparent;border-color:var(--cream-paper);color:var(--cream-paper);}

.breadcrumbs{
  display:flex;flex-wrap:wrap;align-items:center;gap:.5rem;list-style:none;padding:0;
  font-family:var(--font-mono);font-size:.75rem;color:var(--muted-ink);
}
.breadcrumbs__item{display:inline-flex;align-items:center;gap:.5rem;min-height:44px;}
.breadcrumbs__item + .breadcrumbs__item::before{content:"/";color:var(--grid-line);}
.breadcrumbs a{color:var(--slate-mist);text-decoration:none;}
.breadcrumbs a:hover,.breadcrumbs a:focus-visible{color:var(--electric-cyan);}

.content-body{max-width:72ch;font-size:1rem;color:var(--cream-paper);}
.content-body > * + *{margin-top:1.1em;}
.content-body h2{font-size:clamp(1.3rem,2.2vw,1.75rem);margin-top:1.6em;}
.content-body h3{margin-top:1.4em;}
.content-body ul{list-style:none;padding:0;display:grid;gap:.5rem;}
.content-body ul li{position:relative;padding-left:1.25rem;}
.content-body ul li::before{content:"";position:absolute;left:0;top:.78em;width:8px;height:1px;background:var(--warm-gold);}
.content-body ol{list-style:none;counter-reset:cb;padding:0;display:grid;gap:.6rem;}
.content-body ol li{counter-increment:cb;position:relative;padding-left:2.6rem;}
.content-body ol li::before{
  content:counter(cb,decimal-leading-zero);position:absolute;left:0;top:.15em;
  font-family:var(--font-mono);font-size:.8125rem;font-weight:700;color:var(--electric-cyan);
}
.content-body blockquote{margin:0;padding:.75rem 0 .75rem 1.1rem;border-left:2px solid var(--warm-gold);color:var(--slate-mist);}
.content-body code{font-family:var(--font-mono);font-size:.9em;background:rgba(30,58,92,.5);padding:.1em .35em;}
.content-body table{width:100%;border-collapse:collapse;font-size:.9rem;}
.content-body th,.content-body td{border-bottom:1px solid var(--grid-line);padding:.6rem .5rem;text-align:left;vertical-align:top;}
.content-body th{font-family:var(--font-mono);font-size:.75rem;letter-spacing:.08em;color:var(--gold-pale);}

.media-frame{
  position:relative;overflow:hidden;aspect-ratio:16/10;
  background:var(--navy-deck);border:1px solid var(--grid-line);
}
.media-frame > img,.media-frame > video,.media-frame > svg{width:100%;height:100%;object-fit:cover;}
.media-frame--slant{clip-path:polygon(0 0,100% 0,100% 86%,0 100%);}
.media-frame--cut{clip-path:polygon(0 0,88% 0,100% 14%,100% 100%,0 100%);}
.media-frame--wide{aspect-ratio:21/9;}
.media-frame--tall{aspect-ratio:4/5;}
.media-frame--screen{aspect-ratio:3/2;}
.media-frame__caption{
  position:absolute;left:0;bottom:0;padding:.4rem .6rem;
  background:rgba(10,22,38,.86);border-top:1px solid var(--grid-line);
  font-family:var(--font-mono);font-size:.6875rem;color:var(--slate-mist);
}
.media-frame__grid{
  position:absolute;inset:0;pointer-events:none;
  background-image:
    linear-gradient(to right, rgba(31,224,232,.12) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(31,224,232,.12) 1px, transparent 1px);
  background-size:32px 32px;
}
.media-frame__placeholder{
  display:grid;place-items:center;height:100%;padding:1rem;text-align:center;
  color:var(--muted-ink);font-family:var(--font-mono);font-size:.75rem;letter-spacing:.1em;
  background:repeating-linear-gradient(135deg, rgba(30,58,92,.55) 0 12px, transparent 12px 24px);
}

.filter-bar{display:flex;flex-wrap:wrap;gap:.4rem;}
.filter-chip{
  display:inline-flex;align-items:center;min-height:44px;padding:0 .85rem;
  border:1px solid var(--grid-line);background:transparent;color:var(--slate-mist);
  font-family:var(--font-mono);font-size:.75rem;font-weight:700;letter-spacing:.06em;cursor:pointer;
  transition:background-color .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease);
}
.filter-chip:hover,.filter-chip:focus-visible{border-color:var(--electric-cyan);color:var(--cream-paper);}
.filter-chip[aria-pressed="true"]{background:var(--electric-cyan);border-color:var(--electric-cyan);color:var(--ink-abyss);}

.copy-field{
  display:inline-flex;align-items:center;min-height:44px;padding:0;
  background:none;border:0;border-bottom:1px dashed var(--teal-deep);
  color:var(--slate-mist);font-family:var(--font-mono);font-size:.8125rem;font-weight:700;
  text-align:left;word-break:break-all;cursor:pointer;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.copy-field:hover,.copy-field:focus-visible{color:var(--electric-cyan);border-color:var(--electric-cyan);}
.copy-hint{
  grid-column:2;font-family:var(--font-mono);font-size:.6875rem;color:var(--electric-cyan);
  opacity:0;transition:opacity .2s var(--ease);
}
.copy-hint[data-visible]{opacity:1;}

/* ---------- 7. 动效协议 ---------- */
[data-reveal]{
  opacity:0;transform:translateY(14px);
  transition:opacity .32s var(--ease),transform .32s var(--ease);
  transition-delay:var(--reveal-delay,0ms);
}
[data-reveal].is-visible{opacity:1;transform:none;}
[data-highlight]{animation:target-flash 1.2s var(--ease);}
@keyframes target-flash{
  0%{box-shadow:0 0 0 2px var(--electric-cyan);}
  100%{box-shadow:0 0 0 2px rgba(31,224,232,0);}
}

/* ---------- 8. 响应式 ---------- */
@media (max-width:1024px){
  .layout-grid{grid-template-columns:repeat(6,minmax(0,1fr));}
  .col-2,.col-3,.col-4,.col-5,.col-6,.col-7,.col-8,.col-9,.col-10,.col-12{grid-column:span 6;}
  .footer__grid{grid-template-columns:1fr 1fr;}
  .footer__contact{grid-column:1/-1;}
  .nav__note{display:none;}
}

@media (max-width:900px){
  .masthead__top{grid-template-columns:minmax(0,1fr) auto;gap:.5rem;padding-block:.6rem .45rem;}
  .masthead__brand{grid-column:1;grid-row:1;justify-self:start;}
  .masthead__tools{grid-column:2;grid-row:1;}
  .quick-links{display:none;}
  .nav-toggle{display:inline-flex;}
  .masthead__status{
    grid-column:1/-1;grid-row:2;flex-wrap:nowrap;overflow-x:auto;
    padding-bottom:.2rem;scrollbar-width:none;
  }
  .masthead__status::-webkit-scrollbar{height:0;}

  .nav{display:none;border-top:1px solid var(--grid-line);}
  .nav[data-open]{display:block;}
  .nav__list{display:block;overflow:visible;padding-block:.35rem .85rem;}
  .nav__item{border-bottom:1px solid var(--grid-line);}
  .nav__link{width:100%;min-height:52px;padding-inline:.25rem;font-size:1rem;}
  .nav__link::after{left:0;right:auto;top:.7rem;bottom:.7rem;width:0;height:auto;transition:width .18s var(--ease);}
  .nav__link:hover::after{width:3px;background:var(--grid-line);}
  .nav__link[aria-current="page"]::after{width:3px;background:var(--electric-cyan);}

  .footer__grid{grid-template-columns:1fr;gap:1.75rem;}
  .footer__cols{grid-template-columns:repeat(3,minmax(0,1fr));}
  .footer__intro,.footer__trust{max-width:52ch;}
}

@media (max-width:640px){
  body{background-size:48px 48px;}
  #main-content{scroll-margin-top:150px;}
  .chip{font-size:.6875rem;}
  .footer__cols{grid-template-columns:repeat(2,minmax(0,1fr));}
  .footer__contact-row{grid-template-columns:1fr;}
  .footer__contact-row .copy-hint{grid-column:1;}
  .footer__baseline{flex-direction:column;align-items:flex-start;}
}

/* ---------- 9. 无障碍与降级 ---------- */
@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  html{scroll-behavior:auto !important;}
  [data-reveal]{opacity:1;transform:none;}
  .scroll-progress__bar{transition:none;}
  [data-highlight]{animation:none;box-shadow:0 0 0 2px var(--electric-cyan);}
}