/* =========================================================
   欧宝看台 · 共享站点样式 /assets/site.css
   转播台框架：入口轨 + 框架导航 + 精密网格 + 矿物色收束
   ========================================================= */

/* ---------- 0. 设计令牌 ---------- */
:root{
  --indigo-900:#0B1533;
  --indigo-850:#0A1229;
  --indigo-800:#0F1C42;
  --indigo-700:#14224E;
  --blue:#1450C8;
  --blue-bright:#2D7DFF;
  --orange:#FF6A1A;
  --lime:#B6FF3B;
  --gold:#F2B84B;
  --rock:#59606E;
  --bone:#F4F1E8;
  --paper:#FBFCFE;
  --moss:#6F7F5A;
  --clay:#B86B4B;
  --line-dark:#2A3550;
  --line-light:#C9CEDB;
  --ink:#0B1533;
  --ink-soft:#3A4152;
  --text-dim:rgba(244,241,232,.72);
  --text-faint:rgba(244,241,232,.52);

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

  --maxw:1440px;
  --gutter:64px;
  --gap:24px;

  --dur-fast:160ms;
  --dur-base:280ms;
  --dur-slow:420ms;
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{
  -webkit-text-size-adjust:100%;
  scroll-padding-top:130px;
}
@media (prefers-reduced-motion:no-preference){
  html{scroll-behavior:smooth;}
}
body,h1,h2,h3,h4,h5,p,ul,ol,dl,figure,blockquote{margin:0}
ul,ol{padding:0;list-style:none}
img,svg,video{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
a{color:inherit;text-decoration:none}
b,strong{font-weight:700}

/* ---------- 2. 基础排版与页面底色 ---------- */
body{
  min-height:100vh;
  display:flex;
  flex-direction:column;
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.7;
  font-weight:400;
  color:var(--paper);
  background-color:var(--indigo-900);
  background-image:
    linear-gradient(to right, rgba(42,53,80,.55) 0 1px, transparent 1px 100%),
    linear-gradient(to bottom, rgba(42,53,80,.34) 0 1px, transparent 1px 100%),
    radial-gradient(1100px 620px at 82% -8%, rgba(45,125,255,.30), transparent 72%),
    radial-gradient(820px 480px at 2% 4%, rgba(255,106,26,.12), transparent 66%),
    linear-gradient(180deg,#0B1533 0%,#0E1B41 42%,#0A1330 100%);
  background-size:88px 88px, 88px 88px, auto, auto, auto;
  background-attachment:fixed;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
  overflow-x:hidden;
}
main{display:block;flex:1 0 auto}

::selection{background:var(--blue);color:#fff}

:focus-visible{
  outline:3px solid var(--blue-bright);
  outline-offset:3px;
}

h1,h2,h3,h4,h5{
  font-family:var(--font-display);
  font-weight:900;
  line-height:1.16;
  letter-spacing:-.01em;
}

/* ---------- 3. 排版工具 ---------- */
.title-xl{font-size:clamp(32px,4.6vw,64px);line-height:1.1;letter-spacing:-.02em}
.title-lg{font-size:clamp(26px,3vw,40px);line-height:1.15}
.title-md{font-size:clamp(20px,2vw,26px);line-height:1.25}

.lede{
  font-size:clamp(16px,1.15vw,19px);
  line-height:1.82;
  color:var(--text-dim);
  max-width:68ch;
}

.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:10px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.16em;
  line-height:1;
  color:var(--lime);
  margin-bottom:14px;
}
.eyebrow::before{
  content:"";
  width:22px;height:2px;
  background:currentColor;
  flex:none;
}

.mono{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  letter-spacing:.04em;
}

.rule{height:1px;background:var(--line-dark);border:0}
.rule--light{background:var(--line-light)}

.visually-hidden{
  position:absolute!important;
  width:1px;height:1px;
  margin:-1px;padding:0;
  overflow:hidden;
  clip:rect(0 0 0 0);
  clip-path:inset(50%);
  white-space:nowrap;
  border:0;
}

/* ---------- 4. 布局 ---------- */
.shell{
  width:100%;
  max-width:var(--maxw);
  margin-inline:auto;
  padding-inline:var(--gutter);
}

.section{
  position:relative;
  padding-block:clamp(48px,7vw,104px);
}

.section--bone{
  background:var(--bone);
  color:var(--ink);
}
.section--bone .lede{color:var(--ink-soft)}
.section--bone .eyebrow{color:var(--clay)}
.section--bone .rule{background:var(--line-light)}

.grid-12{
  display:grid;
  grid-template-columns:repeat(12,minmax(0,1fr));
  gap:var(--gap);
}
.grid-12 > *{min-width:0}
.span-4{grid-column:span 4}
.span-6{grid-column:span 6}
.span-8{grid-column:span 8}
.span-12{grid-column:span 12}

/* ---------- 5. 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  min-height:44px;
  padding:12px 18px;
  border:1px solid transparent;
  font-family:var(--font-body);
  font-size:14px;
  font-weight:700;
  line-height:1;
  letter-spacing:.02em;
  color:var(--paper);
  background:transparent;
  text-align:center;
  transition:background var(--dur-fast) var(--ease),
             color var(--dur-fast) var(--ease),
             border-color var(--dur-fast) var(--ease),
             transform var(--dur-fast) var(--ease);
}
.btn-primary{
  background:var(--blue);
  border-color:var(--blue-bright);
  color:#fff;
  box-shadow:inset 0 1px 0 rgba(255,255,255,.18);
}
.btn-primary:hover{background:var(--blue-bright);transform:translateY(-1px)}
.btn-ghost{
  border-color:var(--line-dark);
  color:var(--text-dim);
}
.btn-ghost:hover{
  border-color:var(--blue-bright);
  color:#fff;
  background:rgba(45,125,255,.14);
}
.btn-gold{
  border-color:var(--gold);
  color:var(--gold);
}
.btn-gold:hover{background:var(--gold);color:var(--indigo-900)}
.btn-sm{
  min-height:36px;
  padding:9px 13px;
  font-size:12.5px;
}

/* ---------- 6. 标签 ---------- */
.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:4px 9px;
  border:1px solid var(--line-light);
  font-family:var(--font-mono);
  font-size:11.5px;
  font-weight:600;
  line-height:1.4;
  letter-spacing:.08em;
  color:var(--rock);
  background:transparent;
}
.tag--blue{color:var(--blue-bright);border-color:rgba(45,125,255,.55);background:rgba(45,125,255,.10)}
.tag--orange{color:var(--orange);border-color:rgba(255,106,26,.55);background:rgba(255,106,26,.10)}
.tag--lime{color:var(--lime);border-color:rgba(182,255,59,.45);background:rgba(182,255,59,.10)}
.tag--gold{color:var(--gold);border-color:rgba(242,184,75,.55);background:rgba(242,184,75,.10)}
.tag--solid{background:var(--blue);border-color:var(--blue);color:#fff}

/* ---------- 7. 图像容器基础 ---------- */
.media-frame{
  position:relative;
  display:block;
  overflow:hidden;
  aspect-ratio:16/10;
  border:1px solid var(--line-dark);
  background:
    linear-gradient(140deg,var(--indigo-700),var(--indigo-900));
}
.media-frame img{
  width:100%;
  height:100%;
  object-fit:cover;
  filter:contrast(1.06) saturate(.92) brightness(.95);
}
.media-frame::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background:
    linear-gradient(200deg, rgba(45,125,255,.20), transparent 46%, rgba(255,106,26,.16));
  mix-blend-mode:screen;
}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--tall{aspect-ratio:4/5}
.media-frame--square{aspect-ratio:1/1}
.media-frame--bone{
  border-color:var(--line-light);
  background:linear-gradient(140deg,#E7E3D6,#F4F1E8);
}
.media-frame > .tag{
  position:absolute;
  left:0;top:0;
  z-index:2;
}

/* ---------- 8. 面板 / 研究板 ---------- */
.panel{
  position:relative;
  padding:22px;
  border:1px solid var(--line-dark);
  background:rgba(19,31,66,.72);
}
.panel--bone{
  background:var(--paper);
  border-color:var(--line-light);
  color:var(--ink);
}
.panel-head{
  display:flex;
  align-items:baseline;
  justify-content:space-between;
  gap:12px;
  padding-bottom:12px;
  margin-bottom:14px;
  border-bottom:1px solid var(--line-dark);
}
.panel--bone .panel-head{border-bottom-color:var(--line-light)}

/* ---------- 9. 面包屑 ---------- */
.breadcrumb{
  padding-block:18px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.06em;
  color:var(--text-faint);
}
.breadcrumb ol{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
}
.breadcrumb li{display:flex;align-items:center;gap:8px}
.breadcrumb li + li::before{
  content:"/";
  color:var(--line-dark);
}
.breadcrumb a{color:var(--text-dim);border-bottom:1px solid transparent}
.breadcrumb a:hover{color:var(--lime);border-bottom-color:var(--lime)}
.breadcrumb [aria-current="page"]{color:var(--gold)}

/* ---------- 10. 正文窄栏 ---------- */
.prose{
  max-width:72ch;
  font-size:16.5px;
  line-height:1.85;
  color:rgba(244,241,232,.86);
}
.prose > * + *{margin-top:1.1em}
.prose h2{margin-top:2em;font-size:clamp(22px,2.2vw,28px)}
.prose h3{margin-top:1.6em;font-size:clamp(18px,1.6vw,22px)}
.prose ul,.prose ol{padding-left:1.3em;list-style:disc}
.prose ol{list-style:decimal}
.prose a{color:var(--blue-bright);border-bottom:1px solid rgba(45,125,255,.5)}
.prose a:hover{color:var(--lime);border-bottom-color:var(--lime)}
.section--bone .prose{color:var(--ink-soft)}
.prose--legal{font-size:15.5px;line-height:1.8}
.prose--legal h2{margin-top:1.9em}

/* ---------- 11. 跳转链接 ---------- */
.skip-link{
  position:fixed;
  left:16px;
  top:12px;
  z-index:400;
  padding:10px 16px;
  font-weight:700;
  font-size:14px;
  color:var(--indigo-900);
  background:var(--lime);
  transform:translateY(-180%);
  transition:transform var(--dur-fast) var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible{transform:translateY(0)}

/* =========================================================
   12. 头部：入口轨 + 框架导航
   ========================================================= */
.site-header{
  position:sticky;
  top:0;
  z-index:100;
  background:rgba(9,17,40,.90);
  border-bottom:1px solid var(--line-dark);
  -webkit-backdrop-filter:blur(14px) saturate(140%);
  backdrop-filter:blur(14px) saturate(140%);
  transition:box-shadow var(--dur-base) var(--ease);
}
.site-header[data-scrolled]{
  box-shadow:0 18px 40px -24px rgba(0,0,0,.9), 0 1px 0 rgba(45,125,255,.22);
}

/* 12.1 入口轨 */
.rail{
  border-bottom:1px solid rgba(42,53,80,.9);
  background:linear-gradient(90deg, rgba(20,80,200,.22), rgba(11,21,51,0) 55%, rgba(255,106,26,.16));
}
.rail-inner{
  display:flex;
  align-items:center;
  gap:16px;
  min-height:36px;
  max-width:var(--maxw);
  margin-inline:auto;
  padding-inline:var(--gutter);
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.1em;
  overflow-x:auto;
  scrollbar-width:none;
}
.rail-inner::-webkit-scrollbar{display:none}
.rail-label{
  flex:none;
  color:var(--orange);
  font-weight:600;
}
.rail-links{
  display:flex;
  align-items:center;
  flex:none;
}
.rail-links li{display:flex;align-items:center}
.rail-links li + li::before{
  content:"";
  width:1px;height:11px;
  margin-inline:12px;
  background:var(--line-dark);
}
.rail-link{
  display:inline-flex;
  align-items:center;
  padding:5px 2px;
  min-height:24px;
  color:var(--text-dim);
  border-bottom:1px solid transparent;
  transition:color var(--dur-fast) var(--ease),border-color var(--dur-fast) var(--ease);
}
.rail-link:hover{color:var(--lime);border-bottom-color:var(--lime)}
.rail-link:focus-visible{color:var(--lime)}

.version-tag{
  margin-left:auto;
  flex:none;
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding-left:16px;
  color:var(--text-faint);
  white-space:nowrap;
}
.version-tag b{color:var(--paper);font-size:11.5px}
.version-text{color:var(--text-faint)}
.status-dot{
  width:7px;height:7px;
  border-radius:50%;
  background:var(--lime);
  box-shadow:0 0 0 3px rgba(182,255,59,.16);
  animation:statusPulse 2.4s ease-in-out infinite;
}
@keyframes statusPulse{
  0%,100%{box-shadow:0 0 0 0 rgba(182,255,59,.45)}
  50%{box-shadow:0 0 0 5px rgba(182,255,59,0)}
}

/* 12.2 框架条 */
.frame-bar{
  border-bottom:1px solid var(--line-dark);
  background:linear-gradient(180deg, rgba(16,28,64,.94), rgba(10,18,42,.94));
}
.frame-inner{
  display:flex;
  align-items:stretch;
  max-width:var(--maxw);
  min-height:72px;
  margin-inline:auto;
  padding-inline:var(--gutter);
}

/* 品牌 */
.brand{
  display:flex;
  align-items:center;
  gap:12px;
  padding-block:12px;
  margin-right:auto;
  flex:none;
}
.brand-mark{
  position:relative;
  display:grid;
  place-items:center;
  width:38px;height:38px;
  flex:none;
  font-family:var(--font-mono);
  font-size:13px;
  font-weight:700;
  letter-spacing:.02em;
  color:#fff;
  background:linear-gradient(135deg,var(--blue),#0B2E86);
  border:1px solid rgba(45,125,255,.6);
}
.brand-mark::after{
  content:"";
  position:absolute;
  right:0;bottom:0;
  width:10px;height:10px;
  background:var(--orange);
  clip-path:polygon(100% 0,100% 100%,0 100%);
}
.brand-text strong{
  display:block;
  font-family:var(--font-display);
  font-size:19px;
  font-weight:900;
  letter-spacing:.06em;
  line-height:1.2;
  color:var(--paper);
}
.brand-text em{
  display:block;
  font-style:normal;
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.1em;
  line-height:1.4;
  color:var(--text-faint);
  white-space:nowrap;
}
.brand:hover .brand-mark{border-color:var(--lime)}
.brand:hover .brand-text strong{color:var(--lime)}

/* 主导航 */
.primary-nav{
  display:flex;
  align-items:stretch;
  max-height:none;
  visibility:visible;
}
.nav-list{
  display:flex;
  align-items:stretch;
}
.nav-item{display:flex}
.nav-link{
  position:relative;
  display:flex;
  align-items:center;
  gap:7px;
  min-height:72px;
  padding:0 13px;
  border-left:1px solid rgba(42,53,80,.7);
  font-size:14px;
  font-weight:600;
  color:var(--text-dim);
  transition:color var(--dur-fast) var(--ease),background var(--dur-fast) var(--ease);
}
.nav-item:last-child .nav-link{border-right:1px solid rgba(42,53,80,.7)}
.nav-num{
  font-size:9.5px;
  color:rgba(244,241,232,.38);
  transition:color var(--dur-fast) var(--ease);
}
.nav-link:hover{
  color:var(--paper);
  background:rgba(45,125,255,.12);
}
.nav-link:hover .nav-num{color:var(--blue-bright)}
.nav-link[aria-current="page"]{
  color:#fff;
  background:linear-gradient(180deg, rgba(20,80,200,.46), rgba(20,80,200,.06));
}
.nav-link[aria-current="page"] .nav-num{color:var(--orange)}
.nav-link[aria-current="page"]::after{
  content:"";
  position:absolute;
  left:0;right:0;bottom:-1px;
  height:3px;
  background:linear-gradient(90deg,var(--blue-bright),var(--lime));
}

/* 工具区 */
.utility-actions{
  display:flex;
  align-items:center;
  gap:14px;
  margin-left:18px;
  flex:none;
}
.util-link{
  padding:10px 2px;
  font-size:13px;
  color:var(--text-dim);
  border-bottom:1px solid transparent;
  transition:color var(--dur-fast) var(--ease),border-color var(--dur-fast) var(--ease);
}
.util-link:hover{color:var(--paper);border-bottom-color:var(--blue-bright)}

/* 移动端按钮 */
.nav-toggle{
  display:none;
  align-items:center;
  gap:8px;
  min-height:44px;
  margin-left:12px;
  padding:10px 12px;
  border:1px solid var(--line-dark);
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.08em;
  color:var(--paper);
  background:rgba(20,80,200,.10);
  transition:background var(--dur-fast) var(--ease),border-color var(--dur-fast) var(--ease);
}
.nav-toggle:hover{border-color:var(--blue-bright);background:rgba(45,125,255,.20)}
.nav-toggle-bars{
  display:block;
  width:18px;height:12px;
  background:linear-gradient(to bottom,
    currentColor 0 2px, transparent 2px 5px,
    currentColor 5px 7px, transparent 7px 10px,
    currentColor 10px 12px);
}

/* 滚动进度 */
.header-progress{
  position:absolute;
  left:0;bottom:-1px;
  width:100%;height:2px;
  transform:scaleX(0);
  transform-origin:0 50%;
  background:linear-gradient(90deg,var(--blue-bright),var(--lime));
  transition:transform 120ms linear;
  pointer-events:none;
}

/* =========================================================
   13. 页脚
   ========================================================= */
.site-footer{
  position:relative;
  margin-top:auto;
  padding-top:clamp(40px,6vw,72px);
  border-top:1px solid var(--line-dark);
  background:
    linear-gradient(180deg, rgba(10,19,48,.65), rgba(7,14,36,.98)),
    repeating-linear-gradient(90deg, rgba(42,53,80,.42) 0 1px, transparent 1px 88px);
  color:var(--paper);
}
.site-footer::before{
  content:"";
  position:absolute;
  left:0;right:0;top:-1px;
  height:3px;
  background:linear-gradient(90deg,var(--blue) 0 34%,var(--orange) 34% 46%,var(--gold) 46% 56%,var(--lime) 56% 62%,transparent 62%);
}
.footer-shell{padding-bottom:0}

.footer-brand{
  display:block;
  padding-bottom:clamp(24px,3vw,36px);
  border-bottom:1px solid var(--line-dark);
}
.footer-tagline{
  max-width:46ch;
  margin-top:16px;
  font-size:14px;
  line-height:1.8;
  color:var(--text-dim);
}
.footer-contact{
  display:flex;
  flex-direction:column;
  gap:8px;
  margin-top:16px;
}
.contact-row{
  display:flex;
  align-items:center;
  flex-wrap:wrap;
  gap:10px;
  font-size:13px;
}
.contact-label{
  min-width:64px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.1em;
  color:var(--text-faint);
}
.contact-value{color:var(--bone)}
.copy-btn{
  min-height:28px;
  padding:4px 8px;
  border:1px solid var(--line-dark);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  color:var(--text-dim);
  transition:border-color var(--dur-fast) var(--ease),color var(--dur-fast) var(--ease);
}
.copy-btn:hover{border-color:var(--gold);color:var(--gold)}
.copy-btn[data-copied="true"]{border-color:var(--lime);color:var(--lime)}

.footer-cols{
  display:grid;
  grid-template-columns:repeat(4,minmax(0,1fr));
  gap:32px;
  margin-top:clamp(28px,4vw,44px);
}
.footer-col{min-width:0}
.footer-heading{
  padding-bottom:10px;
  margin-bottom:14px;
  border-bottom:1px solid var(--line-dark);
  font-family:var(--font-mono);
  font-size:11.5px;
  font-weight:600;
  letter-spacing:.12em;
  color:var(--text-faint);
}
.footer-list{display:flex;flex-direction:column;gap:2px}
.footer-link{
  display:inline-block;
  padding-block:6px;
  font-size:14px;
  color:var(--text-dim);
  border-bottom:1px solid transparent;
  transition:color var(--dur-fast) var(--ease),border-color var(--dur-fast) var(--ease);
}
.footer-link:hover{color:var(--lime);border-bottom-color:rgba(182,255,59,.55)}
.footer-note{
  margin-top:10px;
  font-size:12.5px;
  line-height:1.7;
  color:var(--text-faint);
}
.footer-note--mono{
  font-size:13px;
  color:var(--gold);
  letter-spacing:.06em;
}

.version-strip{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  margin-top:clamp(32px,4vw,48px);
  border:1px solid var(--line-dark);
  background:rgba(14,26,58,.6);
}
.version-cell{
  padding:16px 20px;
  min-width:0;
}
.version-cell + .version-cell{border-left:1px solid var(--line-dark)}
.version-kicker{
  display:block;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--gold);
}
.version-value{
  display:block;
  margin-top:6px;
  font-size:14px;
  color:var(--paper);
}
.version-link{
  display:inline-block;
  margin-top:6px;
  font-size:14px;
  color:var(--bone);
  border-bottom:1px solid rgba(242,184,75,.5);
  transition:color var(--dur-fast) var(--ease),border-color var(--dur-fast) var(--ease);
}
.version-link:hover{color:var(--lime);border-bottom-color:var(--lime)}

.footer-legal{
  display:grid;
  gap:10px;
  margin-top:clamp(28px,4vw,40px);
  padding-block:24px 36px;
  border-top:1px solid var(--line-dark);
  font-size:12.5px;
  line-height:1.7;
  color:var(--text-faint);
}
.legal-links{
  display:flex;
  flex-wrap:wrap;
  gap:8px 20px;
}
.legal-link{
  color:var(--text-dim);
  border-bottom:1px solid transparent;
  transition:color var(--dur-fast) var(--ease),border-color var(--dur-fast) var(--ease);
}
.legal-link:hover{color:var(--lime);border-bottom-color:var(--lime)}
.legal-meta{max-width:80ch}
.legal-meta--address{color:rgba(244,241,232,.42)}

/* =========================================================
   14. 响应式
   ========================================================= */
@media (max-width:1340px) and (min-width:1201px){
  .nav-link{padding-inline:9px;font-size:13px}
  .util-link{font-size:12px}
}

@media (max-width:1200px){
  .nav-toggle{display:inline-flex}
  .utility-actions{display:none}

  .primary-nav{
    position:absolute;
    top:100%;left:0;right:0;
    display:block;
    max-height:0;
    overflow:hidden;
    visibility:hidden;
    background:linear-gradient(180deg,#0D1A40,#0A1330);
    border-bottom:1px solid var(--line-dark);
    box-shadow:0 28px 48px -30px rgba(0,0,0,.95);
    transition:max-height var(--dur-base) var(--ease), visibility 0s linear var(--dur-base);
  }
  .site-header[data-open] .primary-nav{
    max-height:min(74vh,560px);
    overflow-y:auto;
    visibility:visible;
    transition:max-height var(--dur-base) var(--ease), visibility 0s;
  }
  .site-header[data-open] .nav-toggle{
    background:var(--blue);
    border-color:var(--blue-bright);
    color:#fff;
  }
  .nav-list{flex-direction:column;align-items:stretch}
  .nav-item{width:100%}
  .nav-link{
    justify-content:flex-start;
    min-height:54px;
    padding:0 20px;
    border-left:0;
    border-top:1px solid rgba(42,53,80,.7);
    font-size:15px;
  }
  .nav-item:last-child .nav-link{border-right:0}
  .nav-num{font-size:10px;min-width:20px}
  .nav-link[aria-current="page"]{background:rgba(20,80,200,.30)}
  .nav-link[aria-current="page"]::after{
    left:0;right:auto;top:0;bottom:0;
    width:3px;height:auto;
    background:linear-gradient(180deg,var(--blue-bright),var(--lime));
  }
}

@media (max-width:1024px){
  :root{--gutter:36px}
  .footer-cols{grid-template-columns:repeat(2,minmax(0,1fr));gap:28px}
  .version-strip{grid-template-columns:1fr}
  .version-cell + .version-cell{border-left:0;border-top:1px solid var(--line-dark)}
}

@media (max-width:860px){
  :root{--gutter:24px;--gap:18px}
  .span-4,.span-6,.span-8{grid-column:span 12}
  .frame-inner{min-height:64px}
  .nav-link{min-height:52px}
  .brand-mark{width:34px;height:34px;font-size:12px}
  .brand-text strong{font-size:17px}
  .brand-text em{font-size:9px;letter-spacing:.08em}
  .rail-inner{font-size:11px;gap:12px}
  .version-tag{padding-left:12px}
  .version-text{display:none}
}

@media (max-width:600px){
  :root{--gutter:18px}
  body{font-size:15.5px}
  .footer-cols{grid-template-columns:1fr;gap:24px}
  .rail-links li + li::before{margin-inline:9px}
  .brand-text em{display:none}
  .nav-toggle-text{font-size:11px}
  .contact-label{min-width:auto}
  .footer-legal{padding-block:20px 28px}
}

/* =========================================================
   15. 动效可访问性
   ========================================================= */
@media (prefers-reduced-motion:reduce){
  *,
  *::before,
  *::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  html{scroll-behavior:auto}
  .status-dot{animation:none}
  .header-progress{transition:none}
  .btn:hover{transform:none}
}