/* =========================================================
   AGE(CHINA) · V4 · Shared Site Kit   /assets/site.css
   深海蓝底 + 电光青识别线 + 暖橙行动点 · 锐利直角 · 1px 精密网格
   ========================================================= */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,h5,h6,p,figure,blockquote,dl,dd,ul,ol{margin:0}
ul,ol{padding:0;list-style:none}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;padding:0;cursor:pointer}
a{color:inherit;text-decoration:none}
img,picture,video,canvas,svg{display:block;max-width:100%}
img,video{height:auto}
table{border-collapse:collapse;width:100%}
hr{border:0;margin:0;height:1px;background:var(--line-300)}

/* ---------- 2. 设计令牌 ---------- */
:root{
  --blue-900:#04182B;
  --blue-700:#0A2A45;
  --blue-500:#12466E;
  --cyan-500:#12D6C8;
  --cyan-700:#0A9A93;
  --orange-500:#FF7A2F;
  --mist-050:#EAF2F7;
  --paper-000:#F8FCFE;
  --ink-800:#152430;
  --line-300:#2F5B7A;
  --green-500:#3FBF7F;

  --rail-w:264px;
  --masthead-h:68px;
  --nav-h:53px;
  --gutter:clamp(16px,3.2vw,44px);
  --maxw:1440px;
  --radius:2px;

  --fs-12:.75rem;
  --fs-14:.875rem;
  --fs-16:1rem;
  --fs-20:1.25rem;
  --fs-28:1.75rem;
  --fs-40:2.5rem;
  --fs-64:4rem;
  --fs-88:5.5rem;

  --font-display:"Helvetica Neue","Arial Narrow",Arial,"PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --font-body:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
  --font-mono:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,"Liberation Mono","Courier New",monospace;

  --ease:cubic-bezier(0.2,0.8,0.2,1);
  --dur-fast:120ms;
  --dur:180ms;
  --dur-slow:220ms;

  --line-soft:rgba(47,91,122,.38);
  --text-soft:rgba(234,242,247,.62);
  --text-mute:rgba(234,242,247,.44);
}

/* ---------- 3. 基础与中文排版 ---------- */
body{
  font-family:var(--font-body);
  font-size:var(--fs-16);
  line-height:1.75;
  letter-spacing:.01em;
  color:var(--mist-050);
  background-color:var(--blue-900);
  min-height:100vh;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:-1;
  pointer-events:none;
  background-image:
    linear-gradient(to right,rgba(47,91,122,.13) 1px,transparent 1px),
    linear-gradient(to bottom,rgba(47,91,122,.13) 1px,transparent 1px);
  background-size:72px 72px;
}
body.is-nav-open{overflow:hidden}
h1,h2,h3,h4,h5,h6{line-height:1.2;font-weight:700}
p{text-wrap:pretty}
strong{font-weight:700;color:var(--paper-000)}
::selection{background:var(--cyan-500);color:var(--blue-900)}

/* ---------- 4. 工具类 ---------- */
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.02em}
.display{font-family:var(--font-display);font-weight:800;letter-spacing:-.02em;line-height:1.08}
.lede{font-size:clamp(1rem,1.4vw,1.25rem);line-height:1.8;color:rgba(234,242,247,.82)}
.text-muted{color:var(--text-soft)}
.hairline{height:1px;background:var(--line-300);border:0;margin:0}
.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--font-mono);font-size:var(--fs-12);
  letter-spacing:.2em;text-transform:uppercase;color:var(--cyan-500);
}
.eyebrow::before{content:"";width:24px;height:1px;background:var(--cyan-500)}

/* ---------- 5. 跳转链接 ---------- */
.skip-link{
  position:fixed;top:-120px;left:var(--gutter);z-index:300;
  padding:10px 18px;
  background:var(--cyan-500);color:var(--blue-900);
  font-size:var(--fs-14);font-weight:700;letter-spacing:.04em;
  border-radius:var(--radius);
  transition:top var(--dur) var(--ease);
}
.skip-link:focus{top:12px}

/* ---------- 6. 头部框架 ---------- */
.site-header{
  position:sticky;top:0;z-index:60;
  background:var(--blue-900);
  border-bottom:1px solid var(--line-300);
}
.scroll-progress{
  position:absolute;left:0;right:0;bottom:0;height:2px;
  background:rgba(47,91,122,.35);pointer-events:none;
}
.scroll-progress__bar{
  display:block;height:100%;width:0;
  background:linear-gradient(90deg,var(--cyan-500),var(--orange-500));
  transition:width 90ms linear;
}
.masthead{
  position:relative;z-index:70;
  display:flex;align-items:center;gap:clamp(12px,2vw,28px);
  min-height:var(--masthead-h);
  padding:0 var(--gutter);
  border-bottom:1px solid var(--line-soft);
  background:var(--blue-900);
}

/* 品牌署名 */
.brand{display:flex;align-items:center;gap:12px;flex:0 0 auto;min-width:0}
.brand__mark{
  display:grid;place-items:center;
  width:40px;height:40px;flex:0 0 auto;
  border:1px solid var(--cyan-500);border-radius:var(--radius);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;
  color:var(--cyan-500);
  background:linear-gradient(155deg,rgba(18,214,200,.18),rgba(18,214,200,0));
  transition:background var(--dur) var(--ease),color var(--dur) var(--ease);
}
.brand:hover .brand__mark{background:var(--cyan-500);color:var(--blue-900)}
.brand__text{display:flex;flex-direction:column;line-height:1.3;min-width:0}
.brand__line{
  font-family:var(--font-display);font-weight:800;
  font-size:1rem;letter-spacing:-.01em;color:var(--paper-000);
}
.brand__sub{font-size:11px;letter-spacing:.06em;color:var(--text-mute);white-space:nowrap}
.brand--footer .brand__mark{width:36px;height:36px}

/* 工具区 */
.utility{display:flex;align-items:center;gap:10px;margin-left:auto}
.utility__link{
  display:inline-flex;align-items:center;gap:8px;
  padding:7px 14px;border:1px solid var(--line-300);border-radius:var(--radius);
  font-size:var(--fs-14);color:rgba(234,242,247,.85);
  transition:border-color var(--dur) var(--ease),color var(--dur) var(--ease),background var(--dur) var(--ease);
}
.utility__link::before{content:"";width:6px;height:6px;background:var(--cyan-500);flex:0 0 auto}
.utility__link:hover,.utility__link:focus-visible{border-color:var(--cyan-500);color:var(--cyan-500);background:rgba(18,214,200,.08)}
.utility__chip{
  padding:7px 11px;border:1px solid var(--line-soft);border-radius:var(--radius);
  font-size:11px;letter-spacing:.06em;color:var(--text-soft);
}
.utility__chip.mono{color:var(--cyan-500);border-color:rgba(18,214,200,.4)}

/* 移动按钮 */
.nav-toggle{
  display:none;align-items:center;gap:10px;
  padding:8px 14px;border:1px solid var(--line-300);border-radius:var(--radius);
  font-size:var(--fs-14);color:var(--mist-050);
  transition:border-color var(--dur) var(--ease),color var(--dur) var(--ease);
}
.nav-toggle:hover,.nav-toggle:focus-visible{border-color:var(--cyan-500);color:var(--cyan-500)}
.nav-toggle__bars{position:relative;display:block;width:16px;height:1px;background:currentColor}
.nav-toggle__bars::before,
.nav-toggle__bars::after{
  content:"";position:absolute;left:0;width:16px;height:1px;background:currentColor;
  transition:transform var(--dur) var(--ease);
}
.nav-toggle__bars::before{top:-5px}
.nav-toggle__bars::after{top:5px}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars{background:transparent}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before{transform:translateY(5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after{transform:translateY(-5px) rotate(-45deg)}

/* 主导航 */
.primary-nav{border-bottom:1px solid var(--line-soft);background:var(--blue-900)}
.primary-nav__list{display:flex;flex-wrap:wrap;padding:0 var(--gutter)}
.primary-nav__link{
  position:relative;display:block;
  padding:15px 24px 15px 0;
  font-size:var(--fs-14);letter-spacing:.08em;
  color:rgba(234,242,247,.72);
  transition:color var(--dur) var(--ease);
}
.primary-nav__link::after{
  content:"";position:absolute;left:0;right:24px;bottom:-1px;height:2px;
  background:var(--cyan-500);
  transform:scaleX(0);transform-origin:left center;
  transition:transform var(--dur-slow) var(--ease);
}
.primary-nav__link:hover,.primary-nav__link:focus-visible{color:var(--paper-000)}
.primary-nav__link:hover::after,.primary-nav__link:focus-visible::after{transform:scaleX(1)}
.primary-nav__link[aria-current="page"]{color:var(--cyan-500)}
.primary-nav__link[aria-current="page"]::after{transform:scaleX(1)}

/* 设备分类栏 */
.device-rail{background:var(--blue-900);border-right:1px solid var(--line-300)}
.device-rail__heading{
  display:flex;align-items:center;gap:10px;
  padding:0 20px 14px;
  font-size:11px;letter-spacing:.2em;color:var(--text-mute);
}
.device-rail__heading .mono{color:var(--cyan-500);letter-spacing:.06em}
.device-rail__heading::after{content:"";flex:1;height:1px;background:var(--line-soft)}
.device-rail__list{display:flex;flex-direction:column}
.device-rail__item{display:block}
.device-rail__link{
  display:flex;align-items:baseline;gap:12px;
  padding:11px 20px;
  border-left:2px solid transparent;
  font-size:var(--fs-14);
  color:rgba(234,242,247,.78);
  transition:background var(--dur) var(--ease),color var(--dur) var(--ease),
             border-color var(--dur) var(--ease),padding-left var(--dur) var(--ease);
}
.device-rail__index{font-size:11px;color:rgba(18,214,200,.72);min-width:20px}
.device-rail__name{flex:1 1 auto}
.device-rail__link:hover,
.device-rail__link:focus-visible,
.device-rail__link[aria-current="page"]{
  background:var(--blue-700);
  color:var(--paper-000);
  border-left-color:var(--cyan-500);
  padding-left:24px;
}
.device-rail__note{
  padding:18px 20px 0;
  font-size:11px;letter-spacing:.08em;color:var(--text-mute);
  border-top:1px solid var(--line-soft);
  margin-top:14px;
}

/* ---------- 7. 桌面框架：左栏固定 + 内容右移 ---------- */
@media (min-width:1024px){
  body{padding-left:var(--rail-w)}
  .nav-drawer{display:contents}
  .device-rail{
    position:fixed;left:0;top:0;bottom:0;width:var(--rail-w);
    z-index:70;
    display:flex;flex-direction:column;
    padding:calc(var(--masthead-h) + var(--nav-h) + 22px) 0 24px;
    overflow-y:auto;overscroll-behavior:contain;
    background:linear-gradient(180deg,var(--blue-900) 0%,#03121f 100%);
    border-right:1px solid var(--line-300);
  }
  .device-rail__list{flex:1 1 auto}
}
@media (max-width:1023.98px){
  .nav-toggle{display:inline-flex;order:3}
  .brand__sub{display:none}
  .nav-drawer{
    position:fixed;inset:0;z-index:65;
    padding:calc(var(--masthead-h) + 20px) var(--gutter) 56px;
    background:var(--blue-900);
    overflow-y:auto;overscroll-behavior:contain;
    opacity:0;visibility:hidden;transform:translateY(-10px);
    transition:opacity var(--dur) var(--ease),transform var(--dur) var(--ease),
               visibility 0s linear var(--dur);
  }
  .nav-drawer[data-open]{
    opacity:1;visibility:visible;transform:translateY(0);
    transition-delay:0s;
  }
  .primary-nav{border-bottom:0}
  .primary-nav__list{flex-direction:column;padding:0}
  .primary-nav__link{
    padding:15px 0;font-size:var(--fs-20);letter-spacing:.02em;
    border-bottom:1px solid var(--line-soft);
  }
  .primary-nav__link::after{display:none}
  .primary-nav__link[aria-current="page"]{border-bottom-color:var(--cyan-500)}
  .device-rail{margin-top:32px;border-right:0}
  .device-rail__heading{padding:0 0 14px}
  .device-rail__list{
    display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));
    gap:1px;background:var(--line-soft);
  }
  .device-rail__link{
    background:var(--blue-900);border-left:0;gap:10px;padding:13px 14px;
  }
  .device-rail__link:hover,.device-rail__link:focus-visible{padding-left:14px}
  .device-rail__note{padding:18px 0 0}
}

/* ---------- 8. 页脚 ---------- */
.site-footer{
  position:relative;z-index:1;
  margin-top:clamp(48px,7vw,110px);
  background:var(--blue-900);
  border-top:1px solid var(--line-300);
  color:rgba(234,242,247,.76);
  font-size:var(--fs-14);
}
.footer-inner{
  width:100%;max-width:var(--maxw);
  margin:0 auto;
  padding:clamp(32px,4.5vw,64px) var(--gutter) clamp(20px,3vw,36px);
}
.footer-brand{
  display:flex;flex-wrap:wrap;align-items:center;gap:12px 24px;
  padding-bottom:clamp(20px,2.6vw,32px);
  border-bottom:1px solid var(--line-soft);
}
.footer-brand__note{font-size:11px;letter-spacing:.14em;color:var(--text-mute)}
.footer-row{
  display:grid;grid-template-columns:184px minmax(0,1fr);
  gap:clamp(10px,2.4vw,36px);
  padding:clamp(18px,2.2vw,28px) 0;
  border-bottom:1px solid var(--line-soft);
}
.footer-row__label{
  font-size:11px;letter-spacing:.16em;color:var(--text-mute);
  padding-top:4px;
}
.footer-links{display:flex;flex-wrap:wrap;gap:10px clamp(18px,3vw,40px)}
.footer-links a{
  position:relative;display:inline-block;
  font-size:var(--fs-14);color:rgba(234,242,247,.82);
  transition:color var(--dur) var(--ease);
}
.footer-links a::after{
  content:"";position:absolute;left:0;right:0;bottom:-3px;height:1px;
  background:var(--cyan-500);transform:scaleX(0);transform-origin:left center;
  transition:transform var(--dur) var(--ease);
}
.footer-links a:hover,.footer-links a:focus-visible{color:var(--cyan-500)}
.footer-links a:hover::after,.footer-links a:focus-visible::after{transform:scaleX(1)}

.footer-row--contact{
  border-bottom-color:rgba(18,214,200,.4);
  background:linear-gradient(115deg,rgba(18,214,200,.10),rgba(255,122,47,.08) 62%,rgba(255,122,47,0));
  padding-inline:clamp(12px,2vw,24px);
  border-left:2px solid var(--orange-500);
}
.footer-row--contact .footer-row__label{color:var(--orange-500)}
.footer-contact{display:flex;flex-direction:column;gap:16px;align-items:flex-start}
.footer-contact__list{
  display:grid;gap:14px;width:100%;
  grid-template-columns:repeat(auto-fit,minmax(230px,1fr));
}
.footer-contact__item{display:flex;flex-direction:column;gap:2px;min-width:0}
.footer-contact__key{font-size:11px;letter-spacing:.14em;color:var(--text-mute)}
.footer-contact__val{
  font-size:var(--fs-14);color:var(--paper-000);word-break:break-word;
}
.footer-contact__val.mono{font-size:.9375rem}
.footer-contact__note{
  font-size:var(--fs-12);line-height:1.7;color:var(--text-soft);
  border-left:1px solid var(--cyan-700);padding-left:12px;
}
.footer-contact__cta{align-self:flex-start}
.footer-row--meta{
  display:flex;flex-wrap:wrap;justify-content:space-between;gap:8px 24px;
  grid-template-columns:1fr;
  border-bottom:0;padding-bottom:0;
  font-size:var(--fs-12);color:var(--text-mute);
}

/* ---------- 9. 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;gap:10px;
  padding:11px 22px;border:1px solid var(--line-300);border-radius:var(--radius);
  font-size:var(--fs-14);letter-spacing:.05em;
  color:var(--mist-050);background:transparent;
  transition:background var(--dur) var(--ease),border-color var(--dur) var(--ease),
             color var(--dur) var(--ease),transform var(--dur) var(--ease);
}
.btn:hover,.btn:focus-visible{transform:translateY(-2px)}
.btn--primary{
  background:var(--orange-500);border-color:var(--orange-500);
  color:var(--blue-900);font-weight:700;
}
.btn--primary:hover,.btn--primary:focus-visible{background:#ff8f4d;border-color:#ff8f4d}
.btn--line{border-color:var(--cyan-500);color:var(--cyan-500);background:rgba(18,214,200,.06)}
.btn--line:hover,.btn--line:focus-visible{background:rgba(18,214,200,.18)}
.btn--ghost{border-color:transparent;padding-inline:2px;color:var(--cyan-500)}
.btn--ghost:hover,.btn--ghost:focus-visible{color:var(--paper-000)}

/* ---------- 10. 面包屑 ---------- */
.breadcrumb{padding:0 0 18px}
.breadcrumb__list{
  display:flex;flex-wrap:wrap;gap:8px;align-items:center;
  font-family:var(--font-mono);font-size:var(--fs-12);
  color:var(--text-mute);letter-spacing:.04em;
}
.breadcrumb__list li{display:inline-flex;align-items:center;gap:8px}
.breadcrumb__list li+li::before{content:"/";color:var(--line-300)}
.breadcrumb a{color:rgba(234,242,247,.7);transition:color var(--dur) var(--ease)}
.breadcrumb a:hover,.breadcrumb a:focus-visible{color:var(--cyan-500)}

/* ---------- 11. 容器与网格 ---------- */
.container{
  width:100%;max-width:var(--maxw);
  margin-inline:auto;
  padding-inline:var(--gutter);
}
.container--narrow{max-width:860px}
#main-content{display:block;scroll-margin-top:calc(var(--masthead-h) + var(--nav-h) + 20px)}
.grid{display:grid;gap:clamp(14px,2.2vw,28px)}
.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-12{grid-column:span 12}
@media (max-width:900px){
  .span-3,.span-4,.span-5,.span-6,.span-7,.span-8{grid-column:span 12}
}

/* ---------- 12. 栏目标题条 ---------- */
.section-head{
  display:flex;flex-wrap:wrap;align-items:baseline;gap:10px 20px;
  padding-bottom:16px;margin-bottom:clamp(20px,3vw,36px);
  border-bottom:1px solid var(--line-300);
}
.section-head__index{
  font-family:var(--font-mono);font-size:var(--fs-12);
  letter-spacing:.16em;color:var(--cyan-500);
}
.section-head__title{
  font-family:var(--font-display);font-weight:800;
  font-size:clamp(1.5rem,3.2vw,2.5rem);letter-spacing:-.02em;line-height:1.12;
  color:var(--paper-000);
}
.section-head__note{
  margin-left:auto;font-size:var(--fs-14);color:var(--text-soft);
}

/* ---------- 13. 卡片 ---------- */
.card{
  position:relative;display:flex;flex-direction:column;gap:12px;
  padding:clamp(16px,2vw,24px);
  background:var(--blue-700);
  border:1px solid var(--line-300);border-radius:var(--radius);
  transition:border-color var(--dur) var(--ease),transform var(--dur) var(--ease),
             background var(--dur) var(--ease);
}
.card:hover,.card:focus-within{border-color:var(--cyan-500);transform:translateY(-2px)}
.card__meta{
  display:flex;flex-wrap:wrap;gap:12px;align-items:center;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--text-mute);
}
.card__title{
  font-family:var(--font-display);font-weight:700;
  font-size:clamp(1.125rem,1.9vw,1.375rem);line-height:1.35;
  letter-spacing:-.01em;color:var(--paper-000);
}
.card__text{font-size:var(--fs-14);line-height:1.7;color:rgba(234,242,247,.72)}
.card__foot{
  margin-top:auto;padding-top:12px;border-top:1px solid var(--line-soft);
  font-size:var(--fs-14);color:var(--cyan-500);
}
.card--muted{background:transparent}
.card--accent{
  background:linear-gradient(150deg,var(--blue-500),var(--blue-700) 70%);
  border-color:rgba(18,214,200,.45);
}

/* ---------- 14. 标签与状态 ---------- */
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:3px 10px;border:1px solid var(--line-300);border-radius:var(--radius);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;
  color:rgba(234,242,247,.78);
}
.tag--cyan{border-color:rgba(18,214,200,.5);color:var(--cyan-500)}
.tag--orange{border-color:rgba(255,122,47,.5);color:var(--orange-500)}
.status{
  display:inline-flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;
  color:var(--text-soft);
}
.status::before{content:"";width:7px;height:7px;border-radius:50%;background:var(--green-500);flex:0 0 auto}
.status--cyan::before{background:var(--cyan-500)}
.status--warn::before{background:var(--orange-500)}

/* ---------- 15. 图片容器基础规则 ---------- */
.media{
  position:relative;display:flex;flex-direction:column;
  margin:0;overflow:hidden;
  border:1px solid var(--line-300);border-radius:var(--radius);
  background:var(--blue-700);
}
.media__frame{
  position:relative;width:100%;aspect-ratio:16 / 9;overflow:hidden;
  background-color:var(--blue-700);
  background-image:
    linear-gradient(to right,rgba(47,91,122,.34) 1px,transparent 1px),
    linear-gradient(to bottom,rgba(47,91,122,.34) 1px,transparent 1px);
  background-size:36px 36px;
}
.media__frame > img,
.media__frame > svg,
.media__frame > picture > img{
  width:100%;height:100%;object-fit:cover;object-position:left center;
}
.media--wide .media__frame{aspect-ratio:21 / 9}
.media--square .media__frame{aspect-ratio:1 / 1}
.media--tall .media__frame{aspect-ratio:3 / 4}
.media__caption{
  display:flex;flex-wrap:wrap;gap:6px 14px;justify-content:space-between;
  padding:10px 14px;border-top:1px solid var(--line-soft);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;
  color:var(--text-mute);
}
.media__index{color:var(--cyan-500)}
.media__tag{
  position:absolute;top:10px;left:10px;z-index:2;
  padding:3px 9px;background:rgba(4,24,43,.86);
  border:1px solid var(--cyan-500);border-radius:var(--radius);
  font-family:var(--font-mono);font-size:11px;color:var(--cyan-500);
}

/* ---------- 16. 浅色分区 ---------- */
.section--light{background:var(--mist-050);color:var(--ink-800)}
.section--light .section-head{border-bottom-color:rgba(21,36,48,.2)}
.section--light .section-head__title{color:var(--ink-800)}
.section--light .section-head__note,
.section--light .lede{color:rgba(21,36,48,.72)}
.section--light .card{background:var(--paper-000);border-color:rgba(21,36,48,.14)}
.section--light .card:hover{border-color:var(--cyan-700)}
.section--light .card__title{color:var(--ink-800)}
.section--light .card__text{color:rgba(21,36,48,.72)}
.surface-paper{
  background:var(--paper-000);color:var(--ink-800);
  border:1px solid rgba(21,36,48,.14);border-radius:var(--radius);
}

/* ---------- 17. 显现与复制 ---------- */
:root.js-ready [data-reveal]{
  opacity:0;transform:translateY(10px);
  transition:opacity 320ms var(--ease),transform 320ms var(--ease);
}
:root.js-ready [data-reveal].is-revealed{opacity:1;transform:none}
.copy-btn{
  display:inline-flex;align-items:center;gap:6px;
  padding:2px 9px;border:1px solid var(--line-soft);border-radius:var(--radius);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;
  color:var(--text-soft);
  transition:border-color var(--dur) var(--ease),color var(--dur) var(--ease);
}
.copy-btn:hover,.copy-btn:focus-visible{border-color:var(--cyan-500);color:var(--cyan-500)}
.copy-btn[data-copied]{border-color:var(--green-500);color:var(--green-500)}

/* ---------- 18. 焦点与无障碍 ---------- */
:focus-visible{outline:2px solid var(--cyan-500);outline-offset:2px;border-radius:var(--radius)}
a:focus:not(:focus-visible),button:focus:not(:focus-visible){outline:none}

/* ---------- 19. 响应式收束 ---------- */
@media (max-width:640px){
  :root{--masthead-h:60px;--gutter:16px}
  .utility__chip:not(.mono){display:none}
  .brand__mark{width:34px;height:34px;font-size:10px}
  .brand__line{font-size:.9375rem}
  .nav-toggle__text{display:none}
  .footer-row{grid-template-columns:1fr;gap:10px}
  .footer-row__label{padding-top:0}
  .footer-row--contact{padding-inline:14px}
  .footer-row--meta{flex-direction:column;gap:6px}
}
@media (min-width:641px) and (max-width:1023.98px){
  .utility__chip:not(.mono){display:none}
}

/* ---------- 20. 减少动效 ---------- */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    transition-delay:0s !important;
  }
  :root.js-ready [data-reveal]{opacity:1;transform:none}
  .btn:hover,.card:hover,.card:focus-within{transform:none}
  .scroll-progress__bar{transition:none}
}