/* =========================================================
   银河官网3868 — /assets/site.css
   共享外壳：reset / tokens / 中文排版 / 头部 / 页脚 / 通用组件
   ========================================================= */

/* ---------- tokens ---------- */
:root{
  --void:#050812;
  --deep:#0B1224;
  --silver:#E6EAF2;
  --mist:#8FA3C8;
  --nebula:#7B5CFF;
  --signal:#34D6E8;
  --ember:#FF8A3D;
  --line:#1E2A44;
  --paper:#F7F4EC;
  --ink:#10131c;

  --font-display:"Space Grotesk","HarmonyOS Sans SC","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-body:"Noto Sans SC","HarmonyOS Sans SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","SFMono-Regular",ui-monospace,Menlo,Consolas,"Liberation Mono",monospace;

  --shell:1180px;
  --shell-wide:1360px;
  --gutter:clamp(18px,5vw,64px);
  --header-h:76px;
  --radius:14px;
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ---------- 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,p,figure,blockquote,dl,dd,ul,ol{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}
table{border-collapse:collapse;width:100%}
:where(a,button,summary,[tabindex]):focus-visible{outline:2px solid var(--signal);outline-offset:3px;border-radius:2px}

/* ---------- base ---------- */
html,body{min-height:100%}
body{
  background-color:var(--void);
  background-image:
    radial-gradient(1000px 620px at 78% -10%, rgba(123,92,255,.20), transparent 64%),
    radial-gradient(760px 520px at 2% 0%, rgba(52,214,232,.10), transparent 60%),
    linear-gradient(to right, rgba(30,42,68,.40) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30,42,68,.40) 1px, transparent 1px);
  background-size:auto,auto,120px 120px,120px 120px;
  background-repeat:no-repeat,no-repeat,repeat,repeat;
  background-attachment:fixed;
  color:var(--silver);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.75;
  overflow-x:hidden;
}

#main-content{padding-top:var(--header-h)}
[id]{scroll-margin-top:calc(var(--header-h) + 24px)}

h1,h2,h3,h4{font-family:var(--font-display);font-weight:700;line-height:1.12;letter-spacing:.045em;color:var(--silver)}
h1{font-size:clamp(40px,7.4vw,104px);letter-spacing:.05em}
h2{font-size:clamp(28px,4vw,46px)}
h3{font-size:clamp(20px,2.4vw,28px)}
::selection{background:rgba(52,214,232,.28);color:#fff}

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

/* ---------- utilities ---------- */
.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);clip-path:inset(50%);white-space:nowrap;border:0}
.mono{font-family:var(--font-mono);font-size:12px;letter-spacing:.12em}
.coord{font-family:var(--font-mono);font-size:10px;letter-spacing:.2em;color:rgba(143,163,200,.72);text-transform:uppercase}
.eyebrow{display:inline-flex;align-items:center;gap:10px;font-family:var(--font-mono);font-size:11px;letter-spacing:.22em;color:var(--signal);text-transform:uppercase}
.eyebrow::before{content:"";display:inline-block;width:22px;height:1px;background:currentColor}
.section-title{font-size:clamp(28px,4vw,46px);letter-spacing:.05em}
.lede{font-size:17px;line-height:1.85;color:var(--mist);max-width:38em}

/* ---------- skip link ---------- */
.skip-link{
  position:absolute;left:16px;top:-72px;z-index:300;
  padding:12px 20px;border-radius:0 0 6px 6px;
  background:var(--paper);color:var(--ink);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.12em;
  transition:top .2s var(--ease);
}
.skip-link:focus{top:0}

/* ---------- header ---------- */
.site-header{
  position:fixed;inset:0 0 auto;z-index:120;
  background:transparent;
  border-bottom:1px solid transparent;
  transition:background .26s var(--ease),border-color .26s var(--ease),box-shadow .26s var(--ease);
}
.site-header[data-scrolled="true"]{
  background:rgba(11,18,36,.96);
  border-bottom-color:var(--line);
  box-shadow:0 22px 48px -34px rgba(5,8,18,.95);
}

.header-progress{position:absolute;left:0;right:0;bottom:-1px;height:2px;overflow:hidden;pointer-events:none}
.header-progress__bar{
  display:block;height:100%;width:0;
  background:linear-gradient(90deg,var(--nebula),var(--signal) 58%,var(--ember));
  transition:width .12s linear;
}

.site-header__inner{
  display:flex;align-items:center;
  gap:clamp(12px,2.2vw,36px);
  padding-block:16px;
  transition:padding .26s var(--ease);
}
.site-header[data-scrolled="true"] .site-header__inner{padding-block:9px}

/* brand */
.brand{display:inline-flex;align-items:center;gap:12px;flex:0 0 auto;color:var(--silver)}
.brand__mark{
  position:relative;width:32px;height:32px;flex:0 0 auto;border-radius:50%;
  border:1px solid var(--line);
  display:grid;place-items:center;
  background:radial-gradient(circle at 32% 30%, rgba(123,92,255,.55), rgba(5,8,18,0) 72%);
}
.brand__mark::before{
  content:"";position:absolute;inset:4px;border-radius:50%;
  border:1px dashed rgba(143,163,200,.45);
  transition:transform .5s var(--ease);
}
.brand:hover .brand__mark::before{transform:rotate(90deg)}
.brand__mark-core{
  width:8px;height:8px;border-radius:50%;
  background:var(--signal);
  box-shadow:0 0 12px rgba(52,214,232,.9);
}
.brand__text{display:flex;flex-direction:column;gap:2px}
.brand__name{font-family:var(--font-display);font-weight:700;font-size:17px;line-height:1.15;letter-spacing:.08em}
.brand__tag{font-family:var(--font-mono);font-size:10px;line-height:1.4;letter-spacing:.14em;color:var(--mist)}

/* version chip */
.version-chip{
  display:inline-flex;align-items:center;gap:7px;flex:0 0 auto;
  padding:5px 10px;border-radius:2px;
  border:1px solid rgba(255,138,61,.45);
  background:rgba(255,138,61,.10);
  font-family:var(--font-mono);font-size:11px;line-height:1.5;letter-spacing:.12em;
}
.version-chip__label{color:var(--mist)}
.version-chip__value{color:var(--ember);font-weight:700}

/* primary nav */
.primary-nav{margin-inline:auto}
.primary-nav__list{display:flex;align-items:center;gap:2px}
.primary-nav__item{display:block;flex:0 0 auto}
.primary-nav__link{
  position:relative;display:inline-flex;align-items:baseline;gap:7px;
  padding:10px 13px;
  font-size:14px;letter-spacing:.02em;color:var(--mist);
  transition:color .18s var(--ease);
}
.primary-nav__link::after{
  content:"";position:absolute;left:13px;right:13px;bottom:4px;height:1px;
  background:var(--signal);transform:scaleX(0);transform-origin:left;
  transition:transform .24s var(--ease),background .24s var(--ease);
}
.primary-nav__link:hover,.primary-nav__link:focus-visible{color:var(--silver)}
.primary-nav__link:hover::after,.primary-nav__link:focus-visible::after{transform:scaleX(1)}
.primary-nav__index{font-family:var(--font-mono);font-size:9px;letter-spacing:.1em;color:rgba(143,163,200,.6)}
.primary-nav__link[aria-current="page"]{color:var(--silver)}
.primary-nav__link[aria-current="page"]::after{transform:scaleX(1);background:var(--ember)}
.primary-nav__link[aria-current="page"] .primary-nav__index{color:var(--ember)}

/* header utility */
.header-utility{display:none;flex-direction:column;gap:1px;text-align:right;flex:0 0 auto}
.header-utility__label{font-family:var(--font-mono);font-size:9px;line-height:1.6;letter-spacing:.16em;color:rgba(143,163,200,.7)}
.header-utility__text{font-family:var(--font-mono);font-size:11px;line-height:1.6;letter-spacing:.03em;color:var(--signal)}

/* toggle */
.nav-toggle{
  display:inline-flex;align-items:center;gap:9px;flex:0 0 auto;
  padding:10px 14px;border:1px solid var(--line);border-radius:2px;
  background:rgba(11,18,36,.72);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;color:var(--silver);
  transition:border-color .18s var(--ease),color .18s var(--ease),background .18s var(--ease);
}
.nav-toggle:hover{border-color:rgba(52,214,232,.6);color:var(--signal);background:rgba(11,18,36,.95)}
.nav-toggle__bars{display:inline-flex;flex-direction:column;gap:4px;width:16px}
.nav-toggle__bars span{display:block;height:1px;background:currentColor;transition:transform .22s var(--ease),opacity .22s var(--ease)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:first-child{transform:translateY(2.5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:last-child{transform:translateY(-2.5px) rotate(-45deg)}
.nav-toggle__label{white-space:nowrap}

/* orbit rail */
.orbit-rail{display:none}
.orbit-rail__tick{width:7px;height:1px;background:var(--line)}
.orbit-rail__label{font-family:var(--font-mono);font-size:9px;letter-spacing:.32em;color:rgba(143,163,200,.55)}

/* ---------- buttons ---------- */
.btn{
  display:inline-flex;align-items:center;gap:10px;
  padding:14px 22px;border:1px solid var(--line);border-radius:2px;
  background:rgba(11,18,36,.62);color:var(--silver);
  font-family:var(--font-mono);font-size:12px;line-height:1.4;letter-spacing:.12em;
  transition:transform .18s var(--ease),border-color .18s var(--ease),background .18s var(--ease),color .18s var(--ease);
}
.btn:hover{transform:translateY(-2px);border-color:rgba(52,214,232,.55);color:var(--signal);background:rgba(11,18,36,.92)}
.btn--ember{background:var(--ember);border-color:var(--ember);color:#160903;font-weight:700}
.btn--ember:hover{background:#ff9d5f;border-color:#ff9d5f;color:#160903}
.btn--ghost{background:transparent}
.btn--signal{border-color:rgba(52,214,232,.45);color:var(--signal)}

/* ---------- breadcrumb ---------- */
.breadcrumb{margin-block:26px 0}
.breadcrumb__list{display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--mist)}
.breadcrumb__link{color:var(--mist);border-bottom:1px solid transparent;transition:color .18s var(--ease),border-color .18s var(--ease)}
.breadcrumb__link:hover{color:var(--signal);border-bottom-color:rgba(52,214,232,.5)}
.breadcrumb__sep{color:rgba(143,163,200,.45)}
.breadcrumb__current{color:var(--silver)}

/* ---------- prose ---------- */
.prose{max-width:70ch}
.prose p{margin-block:0 1.15em;max-width:40em;color:rgba(230,234,242,.86)}
.prose h2{font-size:clamp(24px,3vw,34px);margin-block:2.2em .6em}
.prose h3{font-size:20px;margin-block:1.8em .5em}
.prose ul,.prose ol{margin-block:0 1.2em;padding-left:1.25em}
.prose ul{list-style:disc}
.prose ol{list-style:decimal}
.prose li{margin-block:.45em;color:rgba(230,234,242,.86)}
.prose a{color:var(--signal);border-bottom:1px solid rgba(52,214,232,.35)}
.prose strong{color:var(--silver)}
.prose hr{border:0;border-top:1px solid var(--line);margin-block:2.4em}

/* ---------- panels / tags ---------- */
.panel{
  position:relative;overflow:hidden;
  padding:clamp(20px,3vw,32px);
  border:1px solid var(--line);border-radius:var(--radius);
  background:linear-gradient(158deg,rgba(11,18,36,.95),rgba(11,18,36,.70));
}
.panel::before{content:"";position:absolute;top:0;left:0;width:64px;height:1px;background:linear-gradient(90deg,var(--signal),transparent)}
.panel--lift{transition:transform .22s var(--ease),border-color .22s var(--ease),box-shadow .22s var(--ease)}
.panel--lift:hover{transform:translateY(-3px);border-color:rgba(123,92,255,.55);box-shadow:0 26px 50px -40px rgba(123,92,255,.9)}
.panel--paper{
  background:var(--paper);color:var(--ink);border-color:rgba(5,8,18,.18);border-radius:6px;
  box-shadow:0 28px 54px -36px rgba(5,8,18,.95);
}
.panel--paper::before{display:none}
.panel--paper h2,.panel--paper h3,.panel--paper strong{color:var(--ink)}
.panel--paper p,.panel--paper li{color:#2b3040}

.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 9px;border:1px solid var(--line);border-radius:2px;
  background:rgba(5,8,18,.45);color:var(--mist);
  font-family:var(--font-mono);font-size:10px;line-height:1.6;letter-spacing:.14em;
}
.tag--nebula{color:#c3b6ff;border-color:rgba(123,92,255,.45);background:rgba(123,92,255,.12)}
.tag--signal{color:var(--signal);border-color:rgba(52,214,232,.45);background:rgba(52,214,232,.10)}
.tag--ember{color:var(--ember);border-color:rgba(255,138,61,.45);background:rgba(255,138,61,.10)}
.tag--paper{background:var(--paper);color:var(--ink);border-color:rgba(5,8,18,.2)}

/* ---------- media frame (page-stage image container) ---------- */
.media-frame{
  position:relative;margin:0;overflow:hidden;
  border:1px solid var(--line);border-radius:var(--radius);
  aspect-ratio:16/9;
  background:
    radial-gradient(120% 100% at 82% 0%, rgba(123,92,255,.28), transparent 62%),
    radial-gradient(110% 90% at 6% 100%, rgba(52,214,232,.18), transparent 60%),
    linear-gradient(160deg,#0B1224,#050812);
}
.media-frame__grid{
  position:absolute;inset:0;pointer-events:none;opacity:.55;
  background-image:
    linear-gradient(to right, rgba(30,42,68,.85) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(30,42,68,.85) 1px, transparent 1px);
  background-size:48px 48px;
}
.media-frame__img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.media-frame__caption{
  position:absolute;left:0;right:0;bottom:0;
  padding:10px 14px;
  font-family:var(--font-mono);font-size:10px;letter-spacing:.16em;color:var(--mist);
  background:linear-gradient(180deg,transparent,rgba(5,8,18,.9));
}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--square{aspect-ratio:1/1}
.media-frame--tall{aspect-ratio:3/4}

/* ---------- track (page side rail) ---------- */
.track{display:flex;flex-direction:column;gap:2px}
.track__list{display:flex;flex-direction:column;gap:2px}
.track__link{
  display:block;padding:9px 12px;
  border-left:1px solid var(--line);
  font-family:var(--font-mono);font-size:11px;line-height:1.6;letter-spacing:.1em;color:var(--mist);
  transition:color .18s var(--ease),border-color .18s var(--ease),background .18s var(--ease);
}
.track__link:hover{color:var(--silver);border-left-color:rgba(52,214,232,.6)}
.track__link.is-active{
  color:var(--signal);border-left-color:var(--signal);
  background:linear-gradient(90deg,rgba(52,214,232,.12),transparent);
}

/* ---------- footer ---------- */
.site-footer{
  position:relative;overflow:hidden;
  margin-top:clamp(64px,10vw,120px);
  border-top:1px solid var(--line);
  background:linear-gradient(180deg,rgba(11,18,36,.60),rgba(5,8,18,.99) 44%);
}
.footer-beam{position:absolute;top:0;left:0;right:0;height:1px;background:linear-gradient(90deg,transparent,rgba(123,92,255,.85),rgba(52,214,232,.85),transparent)}
.site-footer::after{
  content:"";position:absolute;right:-180px;bottom:-280px;width:560px;height:560px;
  background:radial-gradient(circle,rgba(123,92,255,.22),transparent 68%);
  pointer-events:none;
}
.site-footer > .shell{position:relative;z-index:1}

.footer__top{
  display:flex;flex-wrap:wrap;align-items:baseline;justify-content:space-between;gap:12px 24px;
  padding-block:clamp(32px,5vw,54px) 24px;
  border-bottom:1px solid rgba(30,42,68,.85);
}
.footer__brand-line{
  font-family:var(--font-display);font-weight:700;
  font-size:clamp(17px,2vw,22px);line-height:1.4;letter-spacing:.05em;
  color:var(--silver);max-width:34ch;
}
.footer__coords{font-family:var(--font-mono);font-size:10px;line-height:1.7;letter-spacing:.2em;color:rgba(143,163,200,.72)}

.footer__grid{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));
  gap:clamp(24px,4vw,48px);
  padding-block:clamp(28px,4vw,46px);
}
.footer__col{min-width:0}
.footer__col--nav{grid-column:span 1}
.footer__col--contact{grid-column:span 1}
.footer__col-title{
  margin-bottom:16px;
  font-family:var(--font-mono);font-size:10px;line-height:1.6;letter-spacing:.24em;text-transform:uppercase;
  color:var(--signal);
}
.footer__list{display:grid;gap:9px}
.footer__link{
  display:inline-flex;align-items:baseline;gap:9px;
  padding-bottom:1px;border-bottom:1px solid transparent;
  font-size:14px;color:rgba(230,234,242,.78);
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.footer__link:hover{color:var(--signal);border-bottom-color:rgba(52,214,232,.4)}
.footer__link-index{font-family:var(--font-mono);font-size:9px;line-height:1.6;letter-spacing:.1em;color:rgba(143,163,200,.55)}

.footer__contact{display:grid;gap:12px}
.footer__contact-row{display:grid;grid-template-columns:44px 1fr;gap:10px;align-items:baseline}
.footer__contact dt{font-family:var(--font-mono);font-size:9px;line-height:1.8;letter-spacing:.16em;text-transform:uppercase;color:rgba(143,163,200,.65)}
.footer__contact dd{margin:0;font-size:13.5px;line-height:1.7;color:rgba(230,234,242,.86);word-break:break-word}
.footer__note{
  margin-top:18px;padding-left:12px;border-left:1px solid var(--line);
  font-size:12px;line-height:1.75;color:rgba(143,163,200,.8);max-width:32em;
}

.footer__bottom{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:10px 24px;
  padding-block:20px 28px;
  border-top:1px solid rgba(30,42,68,.85);
  font-family:var(--font-mono);font-size:10px;line-height:1.8;letter-spacing:.14em;
  color:rgba(143,163,200,.75);
}
.footer__icp,.footer__copyright{white-space:nowrap}
.footer__stamp{
  display:inline-flex;align-items:center;gap:8px;
  padding:5px 10px;border-radius:2px;
  background:var(--paper);color:var(--ink);
  font-family:var(--font-mono);font-size:10px;letter-spacing:.16em;
}
.footer__stamp::before{content:"";width:6px;height:6px;border-radius:50%;background:var(--deep)}

/* ---------- responsive ---------- */
@media (max-width:1179px){
  .brand__tag{display:none}
  .primary-nav__link{padding:10px 10px;font-size:13px}
  .primary-nav__link::after{left:10px;right:10px}
}
@media (min-width:1180px){
  .header-utility{display:flex}
}
@media (min-width:1280px){
  .orbit-rail{
    display:flex;position:fixed;left:14px;top:50%;z-index:110;
    transform:translateY(-50%);
    flex-direction:column;align-items:center;gap:14px;
    pointer-events:none;
  }
  .orbit-rail__label{writing-mode:vertical-rl;text-orientation:mixed}
  .orbit-rail__track{position:relative;display:block;width:1px;height:150px;background:var(--line)}
  .orbit-rail__fill{position:absolute;left:0;right:0;top:0;height:0;background:linear-gradient(180deg,var(--nebula),var(--signal))}
}
@media (max-width:900px){
  :root{--header-h:64px}
  .site-header__inner{padding-block:12px;justify-content:space-between}
  .site-header[data-scrolled="true"] .site-header__inner{padding-block:8px}
  .primary-nav{
    position:fixed;left:0;right:0;bottom:0;z-index:130;
    margin-inline:0;
    padding:18px var(--gutter) calc(22px + env(safe-area-inset-bottom,0px));
    background:rgba(11,18,36,.99);
    border-top:1px solid var(--line);
    box-shadow:0 -28px 60px -32px rgba(0,0,0,.95);
    transform:translateY(112%);
    visibility:hidden;
    transition:transform .3s var(--ease),visibility .3s var(--ease);
  }
  .primary-nav[data-open="true"]{transform:translateY(0);visibility:visible}
  .primary-nav__list{display:grid;grid-template-columns:1fr 1fr;gap:2px}
  .primary-nav__item{display:block}
  .primary-nav__link{
    width:100%;justify-content:flex-start;
    padding:14px 10px;font-size:15px;
    border-bottom:1px solid rgba(30,42,68,.7);
  }
  .primary-nav__link::after{display:none}
  .primary-nav__link[aria-current="page"]{color:var(--ember)}
  .primary-nav__link[aria-current="page"] .primary-nav__index{color:var(--ember)}
  body.nav-open{overflow:hidden}
  .footer__bottom{justify-content:flex-start}
}
@media (max-width:560px){
  .primary-nav__list{grid-template-columns:1fr}
  .brand__mark{width:28px;height:28px}
  .brand__name{font-size:15px;letter-spacing:.06em}
  .version-chip{font-size:10px;padding:4px 8px}
  .nav-toggle{padding:9px 12px;font-size:10px}
  .footer__contact-row{grid-template-columns:38px 1fr}
  .footer__brand-line{font-size:16px}
}

/* ---------- motion preference ---------- */
@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;
  }
  .btn:hover,.panel--lift:hover{transform:none}
}