/* ==========================================================================
   /assets/site.css — 亿万总站共享样式
   1 reset · 2 变量 · 3 基础排版 · 4 页头 · 5 页脚 · 6 通用组件 · 7 响应式
   ========================================================================== */

/* 1. RESET ---------------------------------------------------------------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:calc(64px + 18px)}
body,h1,h2,h3,h4,h5,p,ul,ol,li,figure,blockquote,dl,dd{margin:0;padding:0}
ul,ol{list-style:none}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0}
img,svg{display:block;max-width:100%}
[hidden]{display:none !important}

/* 2. 变量 ---------------------------------------------------------------- */
:root{
  --ink:#070B18;
  --panel:#0E1A2F;
  --rock:#3B4148;
  --moss:#5E7A5A;
  --terracotta:#B46A4E;
  --paper:#F1E9DA;
  --cyan:#2FF3E0;
  --violet:#8B5CF6;
  --amber:#FFB020;
  --mist:#A8B4C4;
  --ok:#3DDC97;
  --warn:#FF6B6B;

  --rail-w:88px;
  --head-h:64px;
  --width:1240px;
  --gap:20px;

  --shadow:6px 6px 0 rgba(2,5,12,.68);
  --shadow-soft:0 14px 40px rgba(0,0,0,.42);

  --font-display:"Noto Serif SC","Source Han Serif SC","Songti SC","SimSun",serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-num:"Oswald","Arial Narrow","Bahnschrift Condensed","DIN Alternate",system-ui,sans-serif;
  --font-mono:"JetBrains Mono","SFMono-Regular","Consolas","Liberation Mono",monospace;
}

/* 3. 基础排版 ------------------------------------------------------------- */
html{background:var(--ink)}
body{
  min-height:100vh;
  padding-left:var(--rail-w);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.75;
  font-weight:400;
  color:#D8E0EC;
  background-color:var(--ink);
  background-image:
    radial-gradient(1100px 520px at 80% -10%, rgba(139,92,246,.17), transparent 62%),
    radial-gradient(880px 460px at 4% 0%, rgba(47,243,224,.10), transparent 60%),
    repeating-linear-gradient(90deg, rgba(59,65,72,.16) 0 1px, transparent 1px 96px);
  background-repeat:no-repeat,no-repeat,repeat;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{
  font-family:var(--font-display);
  font-weight:700;
  line-height:1.14;
  color:var(--paper);
  letter-spacing:.01em;
}
h1{font-size:clamp(32px,4.2vw,56px)}
h2{font-size:clamp(26px,3.2vw,40px)}
h3{font-size:clamp(20px,2.2vw,26px)}
p{max-width:70ch}
strong{color:var(--paper);font-weight:600}
::selection{background:var(--cyan);color:#04140F}

:focus-visible{outline:3px solid var(--cyan);outline-offset:2px}
#main-content{scroll-margin-top:calc(var(--head-h) + 16px)}

/* 4. 页头 ---------------------------------------------------------------- */
.site-header{position:relative;z-index:80}

.skip-link{
  position:fixed;
  top:10px;
  left:calc(var(--rail-w) + 16px);
  z-index:200;
  padding:10px 18px;
  font-weight:700;
  font-size:14px;
  color:#04140F;
  background:var(--cyan);
  border:2px solid #04140F;
  box-shadow:var(--shadow);
  transform:translateY(-220%);
  transition:transform .18s ease;
}
.skip-link:focus{transform:translateY(0)}

/* 纵向轨道 */
.rail{
  position:fixed;
  top:0;left:0;bottom:0;
  z-index:90;
  width:var(--rail-w);
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:14px;
  padding:16px 0 18px;
  border-right:2px solid var(--rock);
  background:
    linear-gradient(180deg,#0A1224 0%, #070B18 62%, #060A15 100%),
    repeating-linear-gradient(180deg, rgba(47,243,224,.05) 0 1px, transparent 1px 14px);
}
.rail-mark{
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:8px;
  width:100%;
  padding-bottom:16px;
  border-bottom:1px solid rgba(59,65,72,.9);
  color:var(--paper);
}
.rail-mark-num{
  writing-mode:vertical-rl;
  font-family:var(--font-display);
  font-size:19px;
  letter-spacing:.22em;
  line-height:1;
}
.rail-mark-sub{
  font-family:var(--font-mono);
  font-size:9px;
  letter-spacing:.18em;
  color:var(--cyan);
}
.rail-mark:hover .rail-mark-num{color:var(--cyan)}

.rail-list{
  flex:1;
  display:flex;
  flex-direction:column;
  justify-content:center;
  gap:2px;
  width:100%;
}
.rail-item{width:100%}
.rail-link{
  position:relative;
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:7px;
  width:100%;
  padding:10px 0;
  color:var(--mist);
  border-left:2px solid transparent;
  transition:color .18s ease, background-color .18s ease, border-color .18s ease;
}
.rail-index{
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.1em;
  color:rgba(168,180,196,.65);
}
.rail-label{
  writing-mode:vertical-rl;
  font-size:12px;
  letter-spacing:.24em;
  line-height:1;
}
.rail-link:hover{color:var(--paper);background:rgba(47,243,224,.06)}
.rail-link[aria-current="page"]{
  color:var(--cyan);
  border-left-color:var(--cyan);
  background:linear-gradient(90deg, rgba(47,243,224,.16), rgba(47,243,224,0));
}
.rail-link[aria-current="page"] .rail-index{color:var(--cyan)}

.rail-foot{
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:6px;
  padding-top:14px;
  border-top:1px solid rgba(59,65,72,.9);
  width:100%;
  color:var(--mist);
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.16em;
}
.rail-dot{
  width:8px;height:8px;
  background:var(--ok);
  box-shadow:0 0 0 3px rgba(61,220,151,.18);
}

/* 顶部叠加导航条 */
.header-bar{
  position:fixed;
  top:0;left:var(--rail-w);right:0;
  z-index:80;
  height:var(--head-h);
  background:linear-gradient(180deg, rgba(7,11,24,.94), rgba(7,11,24,.35) 70%, rgba(7,11,24,0));
  border-bottom:2px solid transparent;
  transition:background-color .3s ease, border-color .3s ease, box-shadow .3s ease;
}
.site-header.is-solid .header-bar{
  background:rgba(9,16,32,.97);
  border-bottom-color:var(--rock);
  box-shadow:0 12px 34px rgba(0,0,0,.5);
}
.progress-track{
  position:absolute;
  left:0;right:0;bottom:-2px;
  height:2px;
  background:rgba(59,65,72,.55);
  overflow:hidden;
}
.progress-bar{
  display:block;
  height:100%;
  width:0;
  background:linear-gradient(90deg, var(--cyan), var(--violet));
  transition:width .12s linear;
}
.header-inner{
  max-width:var(--width);
  height:100%;
  margin:0 auto;
  padding:0 32px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:24px;
}

.brand-lockup{display:inline-flex;align-items:center;gap:12px;flex:0 0 auto}
.brand-mark{
  display:grid;
  place-items:center;
  width:36px;height:36px;
  font-family:var(--font-display);
  font-size:19px;
  font-weight:700;
  color:var(--cyan);
  background:rgba(47,243,224,.08);
  border:2px solid var(--cyan);
  box-shadow:3px 3px 0 rgba(47,243,224,.22);
  transition:box-shadow .2s ease, transform .2s ease;
}
.brand-lockup:hover .brand-mark{transform:translate(-1px,-1px);box-shadow:5px 5px 0 rgba(47,243,224,.3)}
.brand-text{display:flex;flex-direction:column;gap:2px;line-height:1}
.brand-name{
  font-family:var(--font-display);
  font-size:18px;
  font-weight:700;
  color:var(--paper);
  letter-spacing:.04em;
}
.brand-sub{
  font-family:var(--font-mono);
  font-size:10px;
  letter-spacing:.3em;
  color:var(--mist);
}

.nav{display:flex;align-items:center;gap:18px;min-width:0}
.nav-list{display:flex;align-items:center;gap:2px;flex-wrap:nowrap}
.nav-link{
  display:inline-block;
  padding:8px 11px;
  font-size:14px;
  font-weight:500;
  color:var(--mist);
  border-bottom:2px solid transparent;
  white-space:nowrap;
  transition:color .18s ease, border-color .18s ease, background-color .18s ease;
}
.nav-link:hover{color:var(--paper);background:rgba(47,243,224,.07)}
.nav-link[aria-current="page"]{color:var(--cyan);border-bottom-color:var(--cyan)}
.nav-cta{flex:0 0 auto}

.nav-toggle{
  display:none;
  align-items:center;
  gap:9px;
  min-height:44px;
  padding:8px 12px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.1em;
  color:var(--paper);
  background:rgba(14,26,47,.92);
  border:2px solid var(--rock);
  box-shadow:3px 3px 0 rgba(2,5,12,.7);
  cursor:pointer;
}
.nav-toggle:hover{border-color:var(--cyan);color:var(--cyan)}
.nav-toggle-icon{display:grid;gap:3px;width:16px}
.nav-toggle-icon span{display:block;height:2px;background:currentColor;transition:transform .2s ease, opacity .2s ease}
.site-header[data-open] .nav-toggle{border-color:var(--violet);color:var(--violet)}
.site-header[data-open] .nav-toggle-icon span:nth-child(1){transform:translateY(5px) rotate(45deg)}
.site-header[data-open] .nav-toggle-icon span:nth-child(2){opacity:0}
.site-header[data-open] .nav-toggle-icon span:nth-child(3){transform:translateY(-5px) rotate(-45deg)}

/* 5. 页脚 ---------------------------------------------------------------- */
.site-footer{
  margin-top:80px;
  border-top:2px solid var(--rock);
  background:
    radial-gradient(700px 300px at 12% 0%, rgba(47,243,224,.09), transparent 66%),
    linear-gradient(180deg, rgba(14,26,47,.92), rgba(7,11,24,1));
}
.footer-inner{
  max-width:var(--width);
  margin:0 auto;
  padding:56px 32px 26px;
}
.footer-top{
  display:grid;
  grid-template-columns:1.5fr 1fr 1fr 1.4fr;
  gap:32px;
}
.footer-col{
  min-width:0;
  padding-top:16px;
  border-top:2px solid var(--rock);
}
.footer-brand{padding-top:16px;border-top:2px solid var(--cyan)}
.footer-kicker{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.24em;
  color:var(--cyan);
  margin-bottom:10px;
}
.footer-brand-name{
  font-family:var(--font-display);
  font-size:30px;
  font-weight:700;
  line-height:1.1;
  color:var(--paper);
  margin-bottom:12px;
}
.footer-line{
  max-width:34ch;
  font-size:14px;
  line-height:1.8;
  color:var(--mist);
  margin-bottom:18px;
}
.footer-home{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:9px 14px;
  font-size:13px;
  font-weight:600;
  color:var(--paper);
  border:2px solid var(--rock);
  box-shadow:4px 4px 0 rgba(2,5,12,.7);
  transition:border-color .18s ease, box-shadow .18s ease, transform .18s ease, color .18s ease;
}
.footer-home:hover{
  color:var(--cyan);
  border-color:var(--cyan);
  transform:translate(-1px,-1px);
  box-shadow:6px 6px 0 rgba(47,243,224,.22);
}
.footer-home-arrow{font-family:var(--font-mono)}

.footer-title{
  display:flex;
  align-items:center;
  gap:9px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:500;
  letter-spacing:.24em;
  color:var(--mist);
  margin-bottom:16px;
}
.footer-title::before{
  content:"";
  width:8px;height:8px;
  background:var(--violet);
  flex:0 0 auto;
}
.footer-list{display:flex;flex-direction:column;gap:10px}
.footer-list a{
  display:inline-block;
  font-size:14px;
  color:#D8E0EC;
  border-bottom:1px solid transparent;
  transition:color .16s ease, border-color .16s ease;
}
.footer-list a:hover{color:var(--cyan);border-bottom-color:var(--cyan)}

.contact-list{display:flex;flex-direction:column;gap:12px}
.contact-row{
  display:grid;
  grid-template-columns:42px minmax(0,1fr) auto;
  align-items:center;
  gap:10px;
}
.contact-row--wide{grid-template-columns:42px minmax(0,1fr);align-items:start}
.contact-key{
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.14em;
  color:var(--mist);
}
.contact-value{
  font-size:14px;
  line-height:1.6;
  color:var(--paper);
  word-break:break-word;
}
.copy-btn{
  padding:4px 9px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.08em;
  color:var(--mist);
  border:1px solid var(--rock);
  background:rgba(14,26,47,.8);
  cursor:pointer;
  transition:color .16s ease, border-color .16s ease, background-color .16s ease;
}
.copy-btn:hover{color:var(--cyan);border-color:var(--cyan);background:rgba(47,243,224,.1)}
.contact-note{
  margin-top:14px;
  font-size:13px;
  line-height:1.7;
  color:var(--mist);
}
.copy-status{
  min-height:20px;
  margin-top:6px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  color:var(--ok);
}

.footer-meta{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  margin-top:40px;
  padding-top:18px;
  border-top:1px dashed rgba(59,65,72,.95);
}
.footer-note{font-size:13px;color:var(--mist);max-width:56ch}
.footer-legal{font-size:12px;color:var(--mist);letter-spacing:.02em}

/* 6. 通用组件 ------------------------------------------------------------ */
.u-container{
  width:100%;
  max-width:var(--width);
  margin:0 auto;
  padding:0 32px;
}
.u-page-top{padding-top:calc(var(--head-h) + 44px)}

.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.06em;
  color:var(--mist);
}
.breadcrumb li{display:flex;align-items:center;gap:8px}
.breadcrumb li + li::before{content:"/";color:var(--rock)}
.breadcrumb a{border-bottom:1px solid transparent}
.breadcrumb a:hover{color:var(--cyan);border-bottom-color:var(--cyan)}
.breadcrumb [aria-current="page"]{color:var(--cyan)}

.stack{display:flex;flex-direction:column;gap:var(--gap,20px)}
.grid{display:grid;gap:var(--gap,20px)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}

.panel{
  position:relative;
  padding:22px;
  background:var(--panel);
  border:2px solid var(--rock);
  box-shadow:var(--shadow);
}
.panel--paper{
  background:var(--paper);
  color:#151A24;
  border-color:#151A24;
}
.panel--paper h2,.panel--paper h3{color:#0B1020}

.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:8px;
  padding:11px 18px;
  font-family:var(--font-body);
  font-size:14px;
  font-weight:600;
  line-height:1.1;
  color:var(--paper);
  background:var(--panel);
  border:2px solid var(--rock);
  box-shadow:4px 4px 0 rgba(2,5,12,.72);
  cursor:pointer;
  transition:transform .16s ease, box-shadow .16s ease, border-color .16s ease, color .16s ease, background-color .16s ease;
}
.btn:hover{
  color:var(--cyan);
  border-color:var(--cyan);
  transform:translate(-1px,-1px);
  box-shadow:6px 6px 0 rgba(47,243,224,.24);
}
.btn:active{transform:translate(2px,2px);box-shadow:1px 1px 0 rgba(2,5,12,.72)}
.btn--primary{background:var(--cyan);color:#04140F;border-color:var(--cyan)}
.btn--primary:hover{background:#61F8EB;color:#04140F;border-color:#61F8EB;box-shadow:6px 6px 0 rgba(139,92,246,.35)}
.btn--ghost{background:transparent;color:var(--paper)}

.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:4px 9px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  line-height:1.4;
  color:var(--paper);
  border:1px solid var(--rock);
  background:rgba(14,26,47,.85);
}
.tag--moss{color:#CFE0CB;border-color:var(--moss);background:rgba(94,122,90,.24)}
.tag--terracotta{color:#F4D8CC;border-color:var(--terracotta);background:rgba(180,106,78,.24)}
.tag--cyan{color:#04140F;border-color:var(--cyan);background:var(--cyan)}
.tag--amber{color:#2A1B00;border-color:var(--amber);background:var(--amber)}
.tag--violet{color:#F2ECFF;border-color:var(--violet);background:rgba(139,92,246,.26)}

.num{
  font-family:var(--font-num);
  font-weight:600;
  line-height:.9;
  letter-spacing:-.01em;
  color:var(--paper);
}
.mono{font-family:var(--font-mono);font-size:.86em;letter-spacing:.04em}
.eyebrow{
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--cyan);
}
.section-title{
  font-family:var(--font-display);
  font-size:clamp(26px,3.4vw,40px);
  line-height:1.14;
  color:var(--paper);
}
.lede{
  max-width:68ch;
  font-size:17px;
  line-height:1.8;
  color:var(--mist);
}

/* 图片容器基础规则（共享页头页脚不放图片） */
.media-frame{
  position:relative;
  display:block;
  overflow:hidden;
  aspect-ratio:16/10;
  border:2px solid var(--rock);
  background:
    linear-gradient(135deg, rgba(139,92,246,.16), rgba(47,243,224,.1) 60%, rgba(7,11,24,.9)),
    var(--panel);
  box-shadow:var(--shadow);
}
.media-frame img{width:100%;height:100%;object-fit:cover;object-position:center}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--square{aspect-ratio:1}
.media-frame[data-label]::after{
  content:attr(data-label);
  position:absolute;
  inset:auto 0 0 0;
  padding:8px 12px;
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.06em;
  color:var(--mist);
  background:rgba(7,11,24,.78);
  border-top:1px solid rgba(59,65,72,.9);
}

/* 分段切换（版本分支） */
.tabs{display:flex;flex-direction:column;gap:18px}
.tablist{
  display:flex;
  flex-wrap:wrap;
  gap:6px;
  padding:6px;
  background:rgba(14,26,47,.85);
  border:2px solid var(--rock);
}
.tab{
  padding:9px 14px;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.08em;
  color:var(--mist);
  border:2px solid transparent;
  cursor:pointer;
  transition:color .16s ease, background-color .16s ease, border-color .16s ease;
}
.tab:hover{color:var(--paper);background:rgba(47,243,224,.08)}
.tab[aria-selected="true"],
.tab.is-active{
  color:#F3EEFF;
  background:rgba(139,92,246,.3);
  border-color:var(--violet);
}
.tab-panel{
  padding:22px;
  background:var(--panel);
  border:2px solid var(--rock);
  box-shadow:var(--shadow);
}
.tab-panel:focus-visible{outline:3px solid var(--cyan);outline-offset:2px}

/* 滚动渐显 */
[data-reveal]{
  opacity:0;
  transform:translateY(14px);
  transition:opacity .6s ease, transform .6s ease;
  transition-delay:calc(var(--reveal-i, 0) * 40ms);
}
[data-reveal].is-in{opacity:1;transform:none}

/* 7. 响应式 -------------------------------------------------------------- */
@media (max-width:1080px){
  .footer-top{grid-template-columns:repeat(2,minmax(0,1fr));gap:28px}
  .nav-link{padding:8px 8px;font-size:13px}
}

@media (max-width:900px){
  body{padding-left:0;padding-bottom:64px}

  .skip-link{left:16px}

  .rail{
    top:auto;
    right:0;
    bottom:0;
    left:0;
    width:auto;
    height:64px;
    flex-direction:row;
    gap:0;
    padding:0 6px;
    border-right:0;
    border-top:2px solid var(--rock);
    overflow-x:auto;
    overflow-y:hidden;
    background:linear-gradient(180deg,#0A1224,#070B18);
  }
  .rail-mark,.rail-foot{display:none}
  .rail-list{
    flex-direction:row;
    flex:1 0 auto;
    justify-content:space-between;
    gap:2px;
    width:100%;
  }
  .rail-item{width:auto;flex:1 0 auto}
  .rail-link{
    flex-direction:row;
    justify-content:center;
    gap:5px;
    min-width:56px;
    padding:8px 6px;
    border-left:0;
    border-bottom:2px solid transparent;
  }
  .rail-label{writing-mode:horizontal-tb;font-size:11px;letter-spacing:0}
  .rail-link[aria-current="page"]{
    border-bottom-color:var(--cyan);
    background:linear-gradient(0deg, rgba(47,243,224,.18), rgba(47,243,224,0));
  }

  .header-bar{left:0}
  .header-inner{padding:0 16px;gap:12px}
  .brand-name{font-size:16px}
  .brand-sub{font-size:9px;letter-spacing:.24em}
  .brand-mark{width:32px;height:32px;font-size:17px}

  .nav{
    position:fixed;
    top:var(--head-h);
    right:0;
    bottom:64px;
    left:0;
    z-index:78;
    display:none;
    flex-direction:column;
    align-items:stretch;
    gap:0;
    padding:18px 16px 24px;
    overflow-y:auto;
    background:rgba(7,11,24,.99);
    border-bottom:2px solid var(--rock);
    box-shadow:var(--shadow-soft);
  }
  .site-header[data-open] .nav{display:flex}
  .nav-list{flex-direction:column;gap:0}
  .nav-item{width:100%}
  .nav-link{
    display:block;
    width:100%;
    padding:14px 12px;
    font-size:16px;
    border-bottom:1px solid rgba(59,65,72,.8);
    border-left:2px solid transparent;
  }
  .nav-link[aria-current="page"]{
    border-bottom-color:rgba(59,65,72,.8);
    border-left-color:var(--cyan);
    background:rgba(47,243,224,.1);
  }
  .nav-cta{display:flex;width:100%;margin-top:18px;padding:14px 18px;font-size:15px}

  .nav-toggle{display:inline-flex}

  .u-container,.u-page-top{padding-left:16px;padding-right:16px}
  .u-page-top{padding-top:calc(var(--head-h) + 28px)}
  .grid--2,.grid--3{grid-template-columns:1fr}
  .footer-inner{padding:40px 16px 20px}
}

@media (max-width:720px){
  body{font-size:16px}
  .footer-top{grid-template-columns:1fr;gap:26px}
  .footer-brand-name{font-size:26px}
  .footer-meta{flex-direction:column;align-items:flex-start;gap:8px}
  .panel,.tab-panel{padding:16px}
  .tablist{padding:4px}
  .tab{flex:1 1 auto;text-align:center}
}

@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  [data-reveal]{opacity:1;transform:none;transition:none}
  .progress-bar{transition:none}
}