/* ============================================================
   北单官网 · 中文站 /assets/site.css
   共享外壳：索引轨道页头 + 记分牌页脚 + 通用组件
   ============================================================ */

:root{
  --ink:#0A1320;
  --ink-deep:#060C14;
  --char:#10161E;
  --graph:#1A2430;
  --mint:#35F2C0;
  --mint-soft:#A8F8DF;
  --mint-deep:#0E6B57;
  --orange:#FF9B4A;
  --fog:#E9F0F7;
  --cool:#9AA9BA;
  --line:#2B3B4E;

  --rail-w:246px;
  --content-max:1120px;

  --radius-sm:8px;
  --radius-md:12px;
  --radius-lg:18px;
  --radius-pill:999px;

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

  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ---------- 01 重置 ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%}
body,h1,h2,h3,h4,p,ul,ol,li,figure,blockquote,dl,dd{margin:0}
ul,ol{list-style:none;padding:0}
img,svg{display:block;max-width:100%;height:auto}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
table{border-collapse:collapse;width:100%}
::selection{background:var(--mint);color:#06110D}

/* ---------- 02 中文排版与页面底 ---------- */
body{
  min-height:100vh;
  background-color:var(--ink);
  background-image:
    radial-gradient(1100px 560px at 92% -12%,rgba(53,242,192,.09),transparent 62%),
    radial-gradient(900px 520px at -6% 108%,rgba(255,155,74,.06),transparent 60%);
  background-repeat:no-repeat;
  background-attachment:fixed;
  color:var(--fog);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.75;
  font-weight:400;
  letter-spacing:.005em;
}
h1,.h1{font-size:clamp(34px,4.4vw,56px);line-height:1.07;font-weight:800;letter-spacing:-.03em}
h2,.h2{font-size:clamp(26px,2.7vw,36px);line-height:1.22;font-weight:800;letter-spacing:-.02em}
h3,.h3{font-size:clamp(19px,1.7vw,24px);line-height:1.33;font-weight:700;letter-spacing:-.01em}
p + p{margin-top:1.2em}
.mono{font-family:var(--font-mono);letter-spacing:.04em}
.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.divider{height:1px;border:0;background:var(--line);margin:clamp(28px,4vw,48px) 0}

:where(a,button,[tabindex],summary):focus-visible{
  outline:2px solid var(--mint);
  outline-offset:2px;
  box-shadow:0 0 0 4px rgba(6,12,20,.92);
  border-radius:var(--radius-sm);
}

/* ---------- 03 跳转链接 ---------- */
.skip-link{
  position:fixed;
  top:10px;
  left:14px;
  z-index:400;
  padding:10px 16px;
  border-radius:var(--radius-sm);
  background:var(--mint);
  color:#06110D;
  font-size:14px;
  font-weight:700;
  letter-spacing:.01em;
  transform:translateY(-200%);
  transition:transform .22s var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible{transform:translateY(0)}

/* ---------- 04 页头 · 索引轨道 ---------- */
.site-header{
  position:fixed;
  top:0;
  left:0;
  bottom:0;
  width:var(--rail-w);
  z-index:120;
  background:transparent;
  border-right:1px solid transparent;
  transition:background-color .35s var(--ease),border-color .35s var(--ease),box-shadow .35s var(--ease);
}
.site-header.is-scrolled{
  background:var(--char);
  border-right-color:var(--line);
  box-shadow:24px 0 50px -46px #000;
}
.header-inner{
  position:relative;
  display:flex;
  flex-direction:column;
  gap:24px;
  height:100%;
  padding:26px 20px 22px;
}

/* 品牌 */
.brand{display:flex;align-items:center;gap:11px;min-height:40px;flex:0 0 auto}
.brand-mark{
  position:relative;
  display:grid;
  place-items:center;
  width:38px;
  height:38px;
  flex:0 0 auto;
  border:1px solid var(--line);
  border-radius:11px;
  background:linear-gradient(155deg,rgba(53,242,192,.24),rgba(53,242,192,0) 72%);
  transition:border-color .25s var(--ease),transform .25s var(--ease);
}
.brand-mark::before{
  content:"";
  width:9px;height:9px;border-radius:50%;
  background:var(--mint);
  box-shadow:0 0 12px rgba(53,242,192,.85);
}
.brand-mark::after{
  content:"";
  position:absolute;inset:6px;
  border:1px solid rgba(53,242,192,.26);
  border-radius:7px;
}
.brand:hover .brand-mark{border-color:rgba(53,242,192,.6);transform:translateY(-1px)}
.brand-text{display:flex;flex-direction:column;line-height:1.15;min-width:0}
.brand-name{font-size:17px;font-weight:800;letter-spacing:-.015em;color:var(--fog)}
.brand-sub{
  margin-top:3px;
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.26em;
  color:var(--cool);
}

/* 导航 */
.site-nav{
  display:flex;
  flex-direction:column;
  gap:18px;
  flex:1 1 auto;
  min-height:0;
  overflow-y:auto;
  scrollbar-width:thin;
  scrollbar-color:var(--line) transparent;
}
.nav-list{display:flex;flex-direction:column;gap:2px}
.nav-link{
  position:relative;
  display:flex;
  align-items:center;
  gap:10px;
  padding:9px 11px;
  border-radius:9px;
  font-size:14.5px;
  font-weight:600;
  letter-spacing:.01em;
  color:var(--cool);
  transition:color .2s var(--ease),background-color .2s var(--ease),transform .2s var(--ease);
}
.nav-index{
  font-family:var(--font-mono);
  font-size:10.5px;
  font-weight:400;
  letter-spacing:.06em;
  color:#54677D;
  transition:color .2s var(--ease);
}
.nav-text{min-width:0}
.nav-link:hover{color:var(--fog);background:rgba(53,242,192,.08);transform:translateX(2px)}
.nav-link:hover .nav-index{color:var(--mint)}
.nav-link[aria-current="page"]{
  background:var(--mint);
  color:#06110D;
  box-shadow:0 10px 24px -16px rgba(53,242,192,.95);
}
.nav-link[aria-current="page"] .nav-index{color:rgba(6,17,13,.58)}
.nav-link[aria-current="page"]:hover{background:var(--mint-soft);color:#06110D;transform:none}

/* 工具入口 */
.header-tools{
  display:flex;
  flex-wrap:wrap;
  gap:6px;
  margin-top:auto;
  padding-top:14px;
  border-top:1px solid var(--line);
}
.tool-link{
  padding:4px 8px;
  border:1px solid var(--line);
  border-radius:6px;
  font-size:11px;
  letter-spacing:.02em;
  color:var(--cool);
  transition:color .2s var(--ease),background-color .2s var(--ease),border-color .2s var(--ease);
}
.tool-link:hover{background:var(--mint-soft);border-color:var(--mint-soft);color:var(--ink)}
.header-cta{width:100%;flex:0 0 auto}

/* 抽屉按钮 */
.nav-toggle{
  display:none;
  position:relative;
  flex-direction:column;
  align-items:center;
  justify-content:center;
  gap:5px;
  width:44px;
  height:44px;
  flex:0 0 auto;
  border:1px solid var(--line);
  border-radius:10px;
  transition:border-color .2s var(--ease),background-color .2s var(--ease);
}
.nav-toggle:hover{border-color:rgba(53,242,192,.55)}
.nav-toggle-bar{
  display:block;
  width:18px;
  height:2px;
  border-radius:2px;
  background:var(--fog);
  transition:transform .25s var(--ease),opacity .2s var(--ease);
}
.nav-toggle[aria-expanded="true"]{border-color:rgba(53,242,192,.55)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1){transform:translateY(7px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3){transform:translateY(-7px) rotate(-45deg)}

/* 进度线 */
.header-progress{
  position:absolute;
  top:0;
  right:0;
  width:2px;
  height:100%;
  overflow:hidden;
  opacity:0;
  pointer-events:none;
  transition:opacity .3s var(--ease);
}
.site-header.is-scrolled .header-progress{opacity:1}
.header-progress-bar{
  display:block;
  width:100%;
  height:100%;
  background:linear-gradient(180deg,var(--mint),var(--orange));
  transform:scaleY(var(--scroll-progress,0));
  transform-origin:top center;
  transition:transform .12s linear;
}

/* ---------- 05 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:11px 18px;
  border-radius:9px;
  font-size:14px;
  font-weight:700;
  line-height:1.2;
  letter-spacing:.01em;
  text-align:center;
  transition:transform .2s var(--ease),background-color .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease),box-shadow .2s var(--ease);
}
.btn-primary{
  background:var(--mint);
  color:#06110D;
  box-shadow:0 14px 30px -18px rgba(53,242,192,.9);
}
.btn-primary:hover{background:var(--mint-soft);transform:translateY(-2px)}
.btn-ghost{
  border:1px solid var(--line);
  background:rgba(26,36,48,.62);
  color:var(--fog);
}
.btn-ghost:hover{border-color:var(--mint);color:var(--mint);transform:translateY(-2px)}
.btn-orange{
  background:var(--orange);
  color:#1A0E05;
  box-shadow:0 14px 30px -20px rgba(255,155,74,.9);
}
.btn-orange:hover{background:#FFB273;transform:translateY(-2px)}

/* ---------- 06 内容容器与网格 ---------- */
.content-wrap{
  width:100%;
  max-width:var(--content-max);
  margin-inline:auto;
  padding-inline:clamp(18px,4vw,36px);
}
.grid-12{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:22px}
.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-12{grid-column:span 12}

/* ---------- 07 文本组件 ---------- */
.section-head{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  gap:10px 18px;
  margin-bottom:clamp(18px,2.4vw,28px);
}
.eyebrow{
  display:inline-flex;
  align-items:center;
  gap:9px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:500;
  letter-spacing:.22em;
  color:var(--mint);
}
.eyebrow::before{
  content:"";
  width:18px;
  height:1px;
  background:var(--mint);
  opacity:.8;
}
.lede{
  max-width:64ch;
  font-size:clamp(16px,1.3vw,18.5px);
  line-height:1.85;
  color:#C4D1DF;
}

/* ---------- 08 面板 / 条带 / 标签 ---------- */
.panel{
  position:relative;
  padding:clamp(18px,2.4vw,28px);
  border:1px solid var(--line);
  border-radius:var(--radius-lg);
  background:linear-gradient(158deg,var(--graph),#141D27 72%);
  transition:transform .25s var(--ease),border-color .25s var(--ease),box-shadow .25s var(--ease);
}
.panel:hover{
  transform:translateY(-2px);
  border-color:#3A5068;
  box-shadow:0 26px 48px -34px #000;
}
.panel-head{
  display:flex;
  align-items:center;
  gap:9px;
  margin-bottom:14px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.16em;
  color:var(--cool);
}
.band{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:14px 20px;
  padding:18px 22px;
  border:1px solid var(--line);
  border-left:3px solid var(--orange);
  border-radius:var(--radius-md);
  background:
    linear-gradient(90deg,rgba(255,155,74,.10),rgba(255,155,74,0) 66%),
    var(--char);
}
.status-dot{
  display:inline-block;
  width:7px;
  height:7px;
  flex:0 0 auto;
  border-radius:50%;
  background:var(--mint);
  box-shadow:0 0 0 4px rgba(53,242,192,.15);
}
.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:3px 10px;
  border:1px solid var(--line);
  border-radius:var(--radius-pill);
  background:rgba(26,36,48,.72);
  font-size:11.5px;
  font-weight:600;
  letter-spacing:.02em;
  color:var(--cool);
}
.tag-mint{background:rgba(53,242,192,.13);border-color:rgba(53,242,192,.42);color:var(--mint-soft)}
.tag-orange{background:rgba(255,155,74,.14);border-color:rgba(255,155,74,.45);color:var(--orange)}

/* ---------- 09 面包屑 ---------- */
.breadcrumbs{
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.08em;
  color:#6C7D91;
}
.breadcrumb-list{display:flex;flex-wrap:wrap;align-items:center;gap:2px}
.breadcrumb-item{display:inline-flex;align-items:center}
.breadcrumb-item:not(:first-child)::before{content:"/";margin-inline:9px;color:#38495C}
.breadcrumb-link{color:#8496AB;transition:color .2s var(--ease)}
.breadcrumb-link:hover{color:var(--mint)}
.breadcrumb-current{color:var(--fog)}

/* ---------- 10 图片容器基础 ---------- */
.media-frame{
  position:relative;
  overflow:hidden;
  border:1px solid var(--line);
  border-radius:var(--radius-lg);
  background:linear-gradient(150deg,var(--graph),#0C131B 78%);
  aspect-ratio:16/10;
}
.media-frame img,
.media-frame svg{width:100%;height:100%;object-fit:cover}
.media-frame-wide{aspect-ratio:21/9}
.media-frame-tall{aspect-ratio:4/5}
.media-caption{
  margin-top:10px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  color:#6C7D91;
}

/* ---------- 11 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:clamp(64px,8vw,104px);
  background:linear-gradient(180deg,#0D141D 0%,var(--ink-deep) 100%);
  border-top:1px solid var(--line);
  color:var(--cool);
}
.site-footer::before{
  content:"";
  position:absolute;
  top:0;left:0;right:0;
  height:1px;
  background:linear-gradient(90deg,transparent 8%,rgba(53,242,192,.55) 50%,transparent 92%);
}
.footer-inner{
  max-width:var(--content-max);
  margin-inline:auto;
  padding:clamp(44px,6vw,72px) clamp(18px,4vw,36px) 26px;
}
.footer-main{
  display:grid;
  grid-template-columns:minmax(240px,1.5fr) repeat(3,minmax(0,1fr));
  gap:clamp(24px,3vw,44px);
}
.footer-brand-name{font-size:22px;font-weight:800;letter-spacing:-.02em;color:var(--fog)}
.footer-brand-sub{
  margin-top:6px;
  font-family:var(--font-mono);
  font-size:10.5px;
  letter-spacing:.22em;
  color:#5F7185;
}
.footer-tagline{
  max-width:34ch;
  margin-top:14px;
  font-size:14px;
  line-height:1.8;
  color:var(--cool);
}
.footer-actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:20px}
.footer-col-title{
  margin-bottom:14px;
  font-family:var(--font-mono);
  font-size:10.5px;
  font-weight:500;
  letter-spacing:.2em;
  color:#5F7185;
}
.footer-links{display:flex;flex-direction:column;gap:9px}
.footer-link{
  display:inline-block;
  font-size:14.5px;
  color:#B7C4D3;
  transition:color .2s var(--ease),transform .2s var(--ease);
}
.footer-link:hover{color:var(--mint);transform:translateX(2px)}

.footer-contact{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(230px,1fr));
  gap:20px 30px;
  margin-top:clamp(30px,4vw,48px);
  padding-top:26px;
  border-top:1px solid var(--line);
}
.contact-row{display:flex;flex-wrap:wrap;align-items:baseline;gap:6px 8px;min-width:0}
.contact-label{
  flex:0 0 100%;
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.18em;
  color:#5F7185;
}
.contact-value{
  font-size:14px;
  color:var(--fog);
  letter-spacing:.01em;
  overflow-wrap:anywhere;
}
.copy-btn{
  padding:2px 9px;
  border:1px solid var(--line);
  border-radius:6px;
  font-size:11px;
  line-height:1.6;
  color:var(--cool);
  transition:color .2s var(--ease),border-color .2s var(--ease),background-color .2s var(--ease);
}
.copy-btn:hover{border-color:var(--mint);color:var(--mint)}
.copy-btn[data-state="copied"]{background:var(--mint);border-color:var(--mint);color:#06110D}
.copy-btn[data-state="failed"]{border-color:var(--orange);color:var(--orange)}

.footer-feedback{
  display:flex;
  align-items:flex-start;
  gap:10px;
  margin-top:26px;
  padding:14px 16px;
  border:1px solid var(--line);
  border-radius:var(--radius-md);
  background:rgba(26,36,48,.5);
  font-size:13.5px;
  line-height:1.7;
  color:var(--cool);
}
.footer-feedback .status-dot{margin-top:9px}

.footer-bottom{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:10px 22px;
  margin-top:30px;
  padding-top:20px;
  border-top:1px solid var(--line);
}
.footer-legal{
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.06em;
  color:#61738A;
}
.footer-legal-links{display:flex;flex-wrap:wrap;gap:8px 16px;margin-left:auto}
.footer-legal-links a{font-size:12.5px;color:#8496AB;transition:color .2s var(--ease)}
.footer-legal-links a:hover{color:var(--mint)}

/* ---------- 12 响应式 ---------- */
@media (max-width:1080px){
  .footer-main{grid-template-columns:minmax(220px,1.4fr) repeat(3,minmax(0,1fr));gap:26px}
}
@media (max-width:900px){
  .col-3,.col-4,.col-5,.col-6,.col-7,.col-8,.col-9{grid-column:1 / -1}
  .footer-main{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-brand{grid-column:1 / -1}
}
@media (max-width:1023px){
  body{padding-left:0;font-size:16.5px}
  .site-header{
    position:sticky;
    top:0;
    left:0;
    right:0;
    bottom:auto;
    width:100%;
    border-right:0;
    border-bottom:1px solid var(--line);
    background:rgba(10,19,32,.92);
    -webkit-backdrop-filter:blur(10px);
    backdrop-filter:blur(10px);
  }
  .site-header.is-scrolled{background:var(--char);box-shadow:0 18px 36px -26px #000}
  .header-inner{
    flex-direction:row;
    flex-wrap:wrap;
    align-items:center;
    gap:12px;
    height:auto;
    padding:12px clamp(14px,4vw,22px);
  }
  .brand{margin-right:auto}
  .nav-toggle{display:flex}
  .site-nav{
    position:absolute;
    top:100%;
    left:0;
    right:0;
    flex:initial;
    gap:14px;
    max-height:0;
    padding:0 18px;
    overflow:hidden;
    opacity:0;
    visibility:hidden;
    transform:translateY(-8px);
    background:var(--char);
    border-bottom:1px solid var(--line);
    transition:max-height .3s var(--ease),opacity .22s var(--ease),transform .22s var(--ease),padding .3s var(--ease),visibility .3s;
  }
  .site-nav[data-open="true"]{
    max-height:min(78vh,620px);
    overflow-y:auto;
    opacity:1;
    visibility:visible;
    transform:none;
    padding:16px 18px 20px;
  }
  .nav-link{padding:12px;font-size:15px}
  .header-tools{margin-top:6px;padding-top:14px}
  .header-cta{width:100%}
  .header-progress{
    top:auto;
    bottom:0;
    left:0;
    right:0;
    width:100%;
    height:2px;
  }
  .header-progress-bar{
    transform:scaleX(var(--scroll-progress,0));
    transform-origin:left center;
  }
  .skip-link{left:14px}
  .panel:hover{transform:none}
}
@media (max-width:640px){
  .grid-12{gap:16px}
  .footer-main{grid-template-columns:1fr;gap:26px}
  .footer-contact{grid-template-columns:1fr;gap:16px}
  .footer-legal-links{margin-left:0}
  .media-frame{aspect-ratio:4/3}
  .media-frame-wide{aspect-ratio:16/9}
  .band{padding:16px;border-radius:var(--radius-sm)}
  .footer-feedback{font-size:13px}
}

/* ---------- 13 减少动态 ---------- */
@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    transition-delay:0ms !important;
    scroll-behavior:auto !important;
  }
  .nav-link:hover,
  .footer-link:hover,
  .btn:hover,
  .panel:hover,
  .brand:hover .brand-mark{transform:none}
}