/* ============================================================
   /assets/site.css — k1体育入口 共享外壳样式
   展区 / 展签 / 说明牌 三段式展览画册语汇
   ============================================================ */

/* ---------- 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}

img,svg,video{display:block;max-width:100%;height:auto}

button,input,select,textarea{font:inherit;color:inherit}

button{background:none;border:0;padding:0;cursor:pointer}

a{color:inherit;text-decoration:none}

hr{border:0;border-top:1px solid var(--steel);margin:0}

/* ---------- 2. Design Tokens ---------- */
:root{
  /* 色板 */
  --deep:#0A2540;
  --abyss:#061627;
  --mid:#1C4E80;
  --mist:#E8EFF7;
  --paper:#FBFCFE;
  --orange:#FF6A17;
  --amber:#FFA53C;
  --neon:#3CFFA6;
  --forest:#0C8F63;
  --ink:#44566B;
  --steel:#C3D4E6;
  --plate-paper:#F1EADC;

  /* 字体 */
  --font-display:"Noto Serif SC","Source Han Serif SC","Songti SC","SimSun",serif;
  --font-sans:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono:"IBM Plex Mono","JetBrains Mono","SFMono-Regular",ui-monospace,Menlo,Consolas,monospace;

  /* 尺度 */
  --gutter:clamp(18px,4.2vw,56px);
  --shell:min(1240px,100%);
  --radius-s:6px;
  --radius-m:16px;
  --radius-l:26px;
  --radius-pill:999px;

  --rule:1px solid var(--steel);
  --rule-dark:1px solid rgba(195,212,230,.24);
  --shadow-plate:0 24px 48px -34px rgba(6,22,39,.55);
  --shadow-deep:0 34px 68px -36px rgba(6,22,39,.85);

  --ease:cubic-bezier(.22,1,.36,1);
  --dur:340ms;
}

/* ---------- 3. 基础排版 ---------- */
body{
  background:var(--paper);
  color:var(--ink);
  font-family:var(--font-sans);
  font-size:clamp(16px,1.05vw,18px);
  line-height:1.75;
  font-weight:400;
  letter-spacing:.01em;
  overflow-x:hidden;
}

h1,h2,h3,h4{color:var(--deep);line-height:1.2;font-weight:700}

strong{color:var(--deep);font-weight:700}

::selection{background:var(--orange);color:#08121f}

/* 文字协议 */
.t-display{
  font-family:var(--font-display);
  font-weight:900;
  font-size:clamp(40px,6.4vw,96px);
  line-height:1.08;
  letter-spacing:-.012em;
  color:var(--deep);
}

.t-data{
  font-family:var(--font-sans);
  font-weight:800;
  font-size:clamp(26px,2.6vw,40px);
  line-height:1.16;
  letter-spacing:-.01em;
  color:var(--deep);
}

.t-num{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-weight:600;
  letter-spacing:.02em;
}

.t-label{
  display:inline-block;
  font-family:var(--font-sans);
  font-size:12px;
  font-weight:700;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--ink);
}

.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;
}

/* ---------- 4. 焦点与可访问性 ---------- */
a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible,
summary:focus-visible{
  outline:2px solid var(--orange);
  outline-offset:3px;
  border-radius:4px;
}

.site-footer a:focus-visible,
.site-footer button:focus-visible,
.site-header a:focus-visible,
.site-header button:focus-visible{
  outline-color:var(--neon);
}

.skip-link{
  position:absolute;
  left:50%;
  top:-100px;
  transform:translateX(-50%);
  z-index:200;
  padding:12px 22px;
  border-radius:0 0 var(--radius-m) var(--radius-m);
  background:var(--orange);
  color:#08121f;
  font-weight:800;
  font-size:14px;
  letter-spacing:.04em;
  transition:top .22s var(--ease);
}

.skip-link:focus{
  top:0;
  color:#08121f;
}

#main-content{scroll-margin-top:104px}
main:focus{outline:none}

/* ---------- 5. 布局容器 ---------- */
.shell{
  width:var(--shell);
  margin-inline:auto;
  padding-inline:var(--gutter);
  position:relative;
}

.section{padding-block:clamp(56px,9vw,120px)}
.section--tight{padding-block:clamp(36px,5vw,64px)}
.section--mist{background:var(--mist)}
.section--paper{background:var(--paper)}

.section--deep{
  background:var(--deep);
  color:var(--mist);
}
.section--deep h1,
.section--deep h2,
.section--deep h3,
.section--deep .t-display,
.section--deep .t-data{color:var(--paper)}

.section--band{
  background:linear-gradient(112deg,var(--abyss) 0%,var(--deep) 44%,var(--mid) 100%);
  color:var(--mist);
  position:relative;
  overflow:hidden;
}

/* ---------- 6. 网格 ---------- */
.grid{display:grid;gap:clamp(18px,2.4vw,32px)}
.grid-12{grid-template-columns:repeat(12,minmax(0,1fr))}

.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}

/* ---------- 7. 正文区 ---------- */
.prose{max-width:66ch}
.prose > * + *{margin-top:1.1em}
.prose p{color:var(--ink)}
.prose h2{
  font-family:var(--font-display);
  font-weight:900;
  font-size:clamp(24px,2.4vw,34px);
  line-height:1.2;
  margin-top:1.9em;
}
.prose h3{font-size:clamp(19px,1.7vw,23px);margin-top:1.6em}
.prose ul,.prose ol{display:grid;gap:.6em;padding-left:1.15em}
.prose ul{list-style:none;padding-left:0}
.prose ul li{position:relative;padding-left:22px}
.prose ul li::before{
  content:"";
  position:absolute;
  left:2px;top:.72em;
  width:9px;height:2px;
  background:var(--orange);
}
.prose a{
  color:var(--forest);
  text-decoration:underline;
  text-underline-offset:3px;
  text-decoration-thickness:1px;
}
.prose a:hover{color:var(--orange)}

/* ---------- 8. 面包屑 ---------- */
.breadcrumbs{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  font-size:13px;
  letter-spacing:.05em;
  color:var(--ink);
}
.breadcrumbs li{display:flex;align-items:center;gap:8px}
.breadcrumbs li + li::before{content:"/";color:var(--steel)}
.breadcrumbs a{transition:color .2s var(--ease)}
.breadcrumbs a:hover{color:var(--orange)}
.breadcrumbs [aria-current="page"]{color:var(--deep);font-weight:700}

/* ---------- 9. 展签 / 说明牌 / 主题带 ---------- */
.plate{
  position:relative;
  display:block;
  background:var(--paper);
  border:var(--rule);
  border-radius:var(--radius-s);
  padding:clamp(20px,2.6vw,32px);
  box-shadow:var(--shadow-plate);
}

.plate--paper{background:var(--plate-paper)}

.plate--deep{
  background:linear-gradient(150deg,var(--deep),var(--abyss));
  border-color:rgba(195,212,230,.26);
  color:var(--mist);
}
.plate--deep h1,
.plate--deep h2,
.plate--deep h3{color:var(--paper)}

.plate__no{
  display:block;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.18em;
  color:var(--orange);
  margin-bottom:12px;
}

.caption{
  font-size:14px;
  line-height:1.7;
  color:var(--ink);
  border-left:2px solid var(--steel);
  padding-left:15px;
}

.band{
  position:relative;
  overflow:hidden;
  background:linear-gradient(110deg,var(--abyss) 0%,var(--deep) 42%,var(--mid) 100%);
  color:var(--paper);
}
.band::after{
  content:"";
  position:absolute;
  top:-40%;
  right:-12%;
  width:56%;
  aspect-ratio:1 / 1;
  border-radius:50%;
  background:radial-gradient(circle,rgba(255,106,23,.34),transparent 64%);
  pointer-events:none;
}
.band::before{
  content:"";
  position:absolute;
  inset:0;
  background-image:repeating-linear-gradient(115deg,rgba(195,212,230,.07) 0 1px,transparent 1px 96px);
  pointer-events:none;
}
.band__inner{
  position:relative;
  z-index:1;
  padding-block:clamp(40px,6vw,84px);
}

/* ---------- 10. Chips / 标签 ---------- */
.chip{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:8px 15px;
  border-radius:var(--radius-pill);
  border:1px solid var(--steel);
  background:var(--paper);
  font-size:13px;
  font-weight:600;
  letter-spacing:.04em;
  color:var(--deep);
  transition:border-color .22s var(--ease),color .22s var(--ease),background .22s var(--ease),transform .22s var(--ease);
}
.chip:hover{border-color:var(--orange);color:var(--orange);transform:translateY(-2px)}
.chip[aria-pressed="true"],
.chip.is-active{
  background:var(--deep);
  border-color:var(--deep);
  color:var(--paper);
}

/* ---------- 11. 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:12px 22px;
  border-radius:var(--radius-pill);
  border:1px solid transparent;
  font-family:var(--font-sans);
  font-size:14px;
  font-weight:700;
  letter-spacing:.03em;
  line-height:1;
  white-space:nowrap;
  transition:transform .22s var(--ease),background .22s var(--ease),border-color .22s var(--ease),color .22s var(--ease),box-shadow .22s var(--ease);
}
.btn:hover{transform:translateY(-2px)}
.btn:active{transform:translateY(0)}

.btn--solid{
  background:linear-gradient(135deg,var(--orange),var(--amber));
  color:#08121f;
  box-shadow:0 12px 26px -16px rgba(255,106,23,.95);
}
.btn--solid:hover{box-shadow:0 16px 32px -16px rgba(255,106,23,1)}

.btn--ghost{
  border-color:rgba(195,212,230,.42);
  background:transparent;
  color:var(--paper);
}
.btn--ghost:hover{border-color:var(--neon);color:var(--neon)}

.btn--outline{
  border-color:var(--steel);
  background:var(--paper);
  color:var(--deep);
}
.btn--outline:hover{border-color:var(--orange);color:var(--orange)}

.btn--dark{
  background:var(--deep);
  color:var(--paper);
}
.btn--dark:hover{background:var(--abyss)}

.btn--sm{padding:9px 16px;font-size:13px}

/* ---------- 12. 响应式图片容器（页面阶段放置图片） ---------- */
.frame{
  position:relative;
  display:block;
  overflow:hidden;
  border:var(--rule);
  border-radius:var(--radius-m);
  background:linear-gradient(145deg,var(--deep),var(--mid));
  box-shadow:var(--shadow-plate);
}
.frame::before{
  content:"";
  display:block;
  padding-top:var(--frame-ratio,62.5%);
}
.frame__media,
.frame img{
  position:absolute;
  inset:0;
  width:100%;
  height:100%;
  object-fit:cover;
}
.frame__plate{
  position:absolute;
  left:14px;
  bottom:14px;
  z-index:2;
  padding:7px 13px;
  border-radius:4px;
  background:rgba(251,252,254,.93);
  color:var(--deep);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
}
.frame--wide{--frame-ratio:42%}
.frame--square{--frame-ratio:100%}
.frame--tall{--frame-ratio:126%}

/* ---------- 13. 可展开内容组 ---------- */
.accordion{border-top:var(--rule)}
.accordion__item{border-bottom:var(--rule)}
.accordion__trigger{
  display:flex;
  align-items:center;
  gap:16px;
  width:100%;
  padding:20px 4px;
  text-align:left;
  font-family:var(--font-sans);
  font-size:clamp(16px,1.5vw,19px);
  font-weight:700;
  color:var(--deep);
  transition:color .22s var(--ease);
}
.accordion__trigger:hover{color:var(--orange)}
.accordion__index{
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.14em;
  color:var(--orange);
  flex:0 0 auto;
}
.accordion__icon{
  position:relative;
  margin-left:auto;
  width:16px;
  height:16px;
  flex:0 0 auto;
}
.accordion__icon::before,
.accordion__icon::after{
  content:"";
  position:absolute;
  background:currentColor;
  transition:transform .3s var(--ease);
}
.accordion__icon::before{top:50%;left:0;width:16px;height:1.5px;transform:translateY(-50%)}
.accordion__icon::after{left:50%;top:0;width:1.5px;height:16px;transform:translateX(-50%)}
[data-accordion-item][data-open] .accordion__icon::after{transform:translateX(-50%) scaleY(0)}
.accordion__panel{
  display:grid;
  grid-template-rows:0fr;
  transition:grid-template-rows .34s var(--ease);
}
[data-accordion-item][data-open] .accordion__panel{grid-template-rows:1fr}
.accordion__panel-inner{overflow:hidden;min-height:0}
.accordion__panel-inner > *:last-child{padding-bottom:24px}

/* ---------- 14. 显现与计数 ---------- */
[data-reveal]{
  opacity:0;
  transform:translateY(12px);
  transition:opacity .42s var(--ease),transform .42s var(--ease);
}
[data-reveal].is-visible{opacity:1;transform:none}

/* ============================================================
   15. 头部：悬浮胶囊浮岛
   ============================================================ */
.site-header{
  position:sticky;
  top:0;
  z-index:80;
  padding:clamp(10px,1.6vw,18px) var(--gutter) 0;
  background:linear-gradient(180deg,rgba(6,22,39,.55),rgba(6,22,39,0));
}

.scroll-progress{
  position:fixed;
  top:0;
  left:0;
  right:0;
  height:3px;
  z-index:140;
  transform:scaleX(0);
  transform-origin:0 50%;
  background:linear-gradient(90deg,var(--neon),var(--amber),var(--orange));
  pointer-events:none;
}

.header-island{
  position:relative;
  width:var(--shell);
  margin-inline:auto;
  display:flex;
  align-items:center;
  gap:clamp(10px,1.6vw,26px);
  padding:9px 11px 9px 16px;
  border-radius:var(--radius-pill);
  border:1px solid rgba(195,212,230,.28);
  background:rgba(10,37,64,.82);
  -webkit-backdrop-filter:blur(14px) saturate(140%);
  backdrop-filter:blur(14px) saturate(140%);
  color:var(--paper);
  box-shadow:0 20px 44px -30px rgba(6,22,39,.95);
  transition:padding .3s var(--ease),background .3s var(--ease),box-shadow .3s var(--ease),border-color .3s var(--ease);
}

.site-header[data-scrolled] .header-island{
  padding:6px 10px 6px 14px;
  background:rgba(6,22,39,.95);
  border-color:rgba(60,255,166,.24);
  box-shadow:0 26px 52px -32px rgba(0,0,0,.95);
}

/* 品牌 */
.brand{
  display:flex;
  align-items:center;
  gap:11px;
  flex:0 0 auto;
  color:var(--paper);
}
.brand__mark{
  display:grid;
  place-items:center;
  width:38px;
  height:38px;
  border-radius:12px;
  background:linear-gradient(140deg,var(--orange),var(--amber));
  color:#08121f;
  font-family:var(--font-mono);
  font-size:15px;
  font-weight:700;
  letter-spacing:.02em;
  box-shadow:0 10px 22px -12px rgba(255,106,23,.95);
  transition:transform .3s var(--ease);
}
.brand:hover .brand__mark{transform:rotate(-6deg)}
.brand__text{display:flex;flex-direction:column;line-height:1.1}
.brand__name{font-size:clamp(15px,1.35vw,17px);font-weight:800;letter-spacing:.02em}
.brand__tagline{
  font-family:var(--font-mono);
  font-size:10.5px;
  letter-spacing:.14em;
  color:rgba(232,239,247,.6);
  margin-top:3px;
}

/* 导航 */
.nav{
  flex:1 1 auto;
  min-width:0;
  display:flex;
  align-items:center;
  justify-content:center;
}
.nav__list{display:flex;align-items:center;gap:2px}
.nav__link{
  display:block;
  padding:10px 14px;
  border-radius:var(--radius-pill);
  font-size:14px;
  font-weight:600;
  letter-spacing:.03em;
  color:rgba(232,239,247,.76);
  transition:background .24s var(--ease),color .24s var(--ease),box-shadow .24s var(--ease);
}
.nav__link:hover{
  background:rgba(232,239,247,.1);
  color:var(--paper);
}
.nav__link[aria-current="page"]{
  color:#ffffff;
  background:linear-gradient(180deg,rgba(255,106,23,.3),rgba(255,106,23,.12));
  box-shadow:inset 0 0 0 1px rgba(255,165,60,.5);
}
.nav__link[aria-current="page"]:hover{
  background:linear-gradient(180deg,rgba(255,106,23,.38),rgba(255,106,23,.18));
}

.nav__quick{display:none}

.header__actions{
  display:flex;
  align-items:center;
  gap:8px;
  flex:0 0 auto;
}

/* 汉堡 */
.nav-toggle{
  display:none;
  align-items:center;
  gap:9px;
  padding:9px 14px 9px 12px;
  border-radius:var(--radius-pill);
  border:1px solid rgba(195,212,230,.32);
  color:var(--paper);
  flex:0 0 auto;
  transition:border-color .22s var(--ease),background .22s var(--ease);
}
.nav-toggle:hover{border-color:var(--neon)}
.nav-toggle[aria-expanded="true"]{
  background:rgba(60,255,166,.14);
  border-color:rgba(60,255,166,.55);
}
.nav-toggle__bars{
  display:grid;
  gap:4px;
  width:18px;
}
.nav-toggle__bars span{
  display:block;
  height:2px;
  border-radius:2px;
  background:currentColor;
  transition:transform .3s var(--ease),opacity .3s var(--ease);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1){transform:translateY(6px) 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(-6px) rotate(-45deg)}
.nav-toggle__text{
  font-size:12px;
  font-weight:700;
  letter-spacing:.14em;
}

/* ============================================================
   16. 页脚
   ============================================================ */
.site-footer{
  position:relative;
  overflow:hidden;
  color:var(--mist);
  border-top:1px solid rgba(195,212,230,.18);
  background:
    radial-gradient(120% 90% at 10% -12%,rgba(28,78,128,.78),transparent 62%),
    radial-gradient(78% 68% at 92% 4%,rgba(255,106,23,.18),transparent 64%),
    linear-gradient(180deg,var(--abyss) 0%,var(--deep) 66%,var(--abyss) 100%);
}
.site-footer::before{
  content:"";
  position:absolute;
  inset:0;
  background-image:repeating-linear-gradient(115deg,rgba(195,212,230,.05) 0 1px,transparent 1px 92px);
  pointer-events:none;
}
.site-footer__inner{
  position:relative;
  z-index:1;
  padding-block:clamp(48px,7vw,96px) clamp(24px,3.4vw,40px);
}

.site-footer__grid{
  display:grid;
  grid-template-columns:minmax(0,1.1fr) minmax(0,1.6fr);
  gap:clamp(30px,4vw,60px);
}

.site-footer__brand{max-width:46ch}

.footer-logo{
  display:inline-flex;
  align-items:center;
  gap:11px;
  color:var(--paper);
}
.footer-logo__mark{
  display:grid;
  place-items:center;
  width:36px;
  height:36px;
  border-radius:11px;
  background:linear-gradient(140deg,var(--orange),var(--amber));
  color:#08121f;
  font-family:var(--font-mono);
  font-size:14px;
  font-weight:700;
}
.footer-logo__name{font-size:19px;font-weight:800;letter-spacing:.02em}

.footer-tagline{
  margin-top:16px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.16em;
  color:var(--neon);
}
.footer-desc{
  margin-top:12px;
  font-size:14.5px;
  line-height:1.8;
  color:rgba(232,239,247,.72);
}

.footer-stats{
  display:flex;
  flex-wrap:wrap;
  gap:clamp(18px,2.6vw,36px);
  margin-top:26px;
  padding-top:22px;
  border-top:1px dashed rgba(195,212,230,.3);
}
.footer-stat{min-width:76px}
.footer-stat__num{
  display:block;
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  font-size:clamp(28px,3.2vw,42px);
  line-height:1;
  letter-spacing:.02em;
  color:var(--neon);
}
.footer-stat__label{
  display:block;
  margin-top:8px;
  font-size:12px;
  letter-spacing:.14em;
  color:rgba(232,239,247,.6);
}

.footer-nav{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:clamp(22px,2.6vw,38px);
}
.footer-col__title{
  font-size:12px;
  font-weight:700;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:rgba(232,239,247,.5);
}
.footer-col__links{
  display:grid;
  gap:11px;
  margin-top:16px;
}
.footer-col__links a{
  display:inline-flex;
  align-items:center;
  gap:9px;
  font-size:14.5px;
  color:rgba(232,239,247,.84);
  transition:color .22s var(--ease),transform .22s var(--ease);
}
.footer-col__links a::before{
  content:"";
  width:7px;
  height:1px;
  background:currentColor;
  opacity:.55;
  transition:width .22s var(--ease),background .22s var(--ease);
}
.footer-col__links a:hover{color:var(--orange)}
.footer-col__links a:hover::before{width:14px;background:var(--orange)}

.footer-contact{
  margin-top:clamp(34px,4.4vw,56px);
  padding-top:clamp(24px,3vw,36px);
  border-top:1px solid rgba(195,212,230,.18);
}
.footer-contact__title{
  font-size:12px;
  font-weight:700;
  letter-spacing:.16em;
  text-transform:uppercase;
  color:rgba(232,239,247,.5);
  font-family:var(--font-sans);
}
.footer-contact__list{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(272px,1fr));
  gap:14px;
  margin-top:18px;
}
.footer-contact__item{
  display:flex;
  align-items:center;
  flex-wrap:wrap;
  gap:10px 12px;
  padding:13px 16px;
  border:1px solid rgba(195,212,230,.22);
  border-radius:14px;
  background:rgba(251,252,254,.05);
  transition:border-color .22s var(--ease),background .22s var(--ease);
}
.footer-contact__item:hover{
  border-color:rgba(60,255,166,.4);
  background:rgba(251,252,254,.08);
}
.footer-contact__item--wide{grid-column:1 / -1}
.footer-contact__key{
  font-size:11px;
  letter-spacing:.16em;
  color:rgba(232,239,247,.52);
  flex:0 0 auto;
}
.footer-contact__val{
  font-family:var(--font-mono);
  font-size:13.5px;
  color:var(--paper);
  word-break:break-all;
}
.footer-contact__status{
  font-size:12px;
  color:var(--neon);
  opacity:0;
  transition:opacity .2s var(--ease);
}
.footer-contact__status[data-visible]{opacity:1}
.footer-contact__note{
  margin-top:16px;
  font-size:13px;
  line-height:1.75;
  color:rgba(232,239,247,.58);
  max-width:70ch;
}

.copy-btn{
  margin-left:auto;
  padding:6px 13px;
  border-radius:var(--radius-pill);
  border:1px solid rgba(60,255,166,.42);
  color:var(--neon);
  font-size:12px;
  font-weight:700;
  letter-spacing:.08em;
  transition:background .22s var(--ease),color .22s var(--ease),border-color .22s var(--ease);
}
.copy-btn:hover{background:rgba(60,255,166,.15)}
.copy-btn[data-copied="true"]{
  background:var(--neon);
  border-color:var(--neon);
  color:#08121f;
}

.site-footer__base{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px 26px;
  margin-top:clamp(28px,4vw,46px);
  padding-top:20px;
  border-top:1px solid rgba(195,212,230,.18);
  font-size:12.5px;
  color:rgba(232,239,247,.6);
}
.footer-base__line{
  font-family:var(--font-mono);
  letter-spacing:.06em;
}
.footer-base__legal{letter-spacing:.04em}

/* ============================================================
   17. 响应式
   ============================================================ */
@media (max-width:1120px){
  .brand__tagline{display:none}
  .header__actions .btn--ghost{display:none}
  .nav__link{padding:10px 11px;font-size:13.5px}
}

@media (max-width:1000px){
  .site-footer__grid{grid-template-columns:1fr}
  .grid-12{grid-template-columns:repeat(6,minmax(0,1fr))}
  .col-2,.col-3,.col-4,.col-5,.col-6{grid-column:span 6}
  .col-7,.col-8,.col-9,.col-10{grid-column:span 6}
}

@media (max-width:940px){
  .header__actions{display:none}
  .nav-toggle{display:inline-flex}

  .site-header{padding-top:10px}

  .nav{
    position:absolute;
    left:0;
    right:0;
    top:calc(100% + 10px);
    display:block;
    padding:14px;
    border-radius:var(--radius-l);
    border:1px solid rgba(195,212,230,.24);
    background:rgba(6,22,39,.97);
    -webkit-backdrop-filter:blur(16px);
    backdrop-filter:blur(16px);
    box-shadow:var(--shadow-deep);
    opacity:0;
    visibility:hidden;
    transform:translateY(-10px);
    transition:opacity .26s var(--ease),transform .26s var(--ease),visibility .26s linear;
  }
  .nav[data-open]{
    opacity:1;
    visibility:visible;
    transform:none;
  }

  .nav__list{flex-direction:column;align-items:stretch;gap:2px}
  .nav__link{
    padding:13px 15px;
    border-radius:14px;
    font-size:15.5px;
  }
  .nav__link[aria-current="page"]{box-shadow:inset 0 0 0 1px rgba(255,165,60,.5)}

  .nav__quick{
    display:grid;
    grid-template-columns:1fr 1fr;
    gap:10px;
    margin-top:12px;
    padding-top:14px;
    border-top:1px solid rgba(195,212,230,.18);
  }
  .nav__quick .btn{width:100%}
}

@media (max-width:820px){
  .footer-nav{grid-template-columns:repeat(2,minmax(0,1fr))}
}

@media (max-width:620px){
  .header-island{gap:10px;padding:8px 9px 8px 12px}
  .brand__mark{width:34px;height:34px;border-radius:10px;font-size:13.5px}

  .footer-nav{grid-template-columns:1fr}
  .footer-contact__list{grid-template-columns:1fr}
  .footer-contact__item{align-items:flex-start}
  .copy-btn{margin-left:0}

  .site-footer__base{flex-direction:column;align-items:flex-start}
}

@media (max-width:400px){
  .brand__name{font-size:14px}
  .nav-toggle{padding:8px 11px}
  .nav-toggle__text{display:none}
}

/* ---------- 18. 动效退化 ---------- */
@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;
  }
  [data-reveal]{opacity:1;transform:none}
  [data-reveal].is-visible{opacity:1;transform:none}
  .btn:hover,
  .chip:hover{transform:none}
  .footer-col__links a:hover{transform:none}
}