/* ==========================================================================
   开元 · 中国站 — /assets/site.css
   共享外壳：reset / 设计令牌 / 中文排版 / 头部 / 页脚 / 通用组件
   ========================================================================== */

/* 1. 设计令牌 -------------------------------------------------------------- */
:root{
  --obsidian:#0B0E13;
  --carbon:#151A21;
  --ink-line:#333D4A;
  --grayblue:#263244;
  --amber:#D9A441;
  --gold:#FFD98A;
  --celadon:#4FB59A;
  --signal:#F07A34;
  --mist:#A9B4C4;
  --paper:#F4F1EA;
  --rice:#EFE3C8;

  --font-display:"Noto Sans SC Condensed","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-serif:"Noto Serif SC","Source Han Serif SC","Songti SC","SimSun",Georgia,serif;
  --font-body:"Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"JetBrains Mono","Roboto Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --line-soft:rgba(51,61,74,.55);
  --w-max:1360px;
  --gap:clamp(16px,3vw,40px);
  --header-h:88px;
  --shadow-soft:0 1px 0 rgba(0,0,0,.35),0 14px 34px rgba(0,0,0,.3);
}

/* 2. Reset 与基础 ---------------------------------------------------------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;
  background:var(--obsidian);
  color:var(--mist);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.75;
  font-weight:400;
  letter-spacing:.012em;
  -webkit-font-smoothing:antialiased;
}
img,svg,video{display:block;max-width:100%;height:auto}
a{color:var(--gold);text-decoration:none}
a:hover{color:var(--paper)}
h1,h2,h3,h4,h5,p,figure,blockquote,dl,dd,fieldset{margin:0}
ul,ol{margin:0;padding:0;list-style:none}
table{border-collapse:collapse;width:100%}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
:focus-visible{outline:2px solid var(--gold);outline-offset:3px}
[id]{scroll-margin-top:calc(var(--header-h) + 24px)}

/* 3. 文字层 ---------------------------------------------------------------- */
h1,h2,h3{font-family:var(--font-display);font-weight:700;color:var(--paper);line-height:1.25;letter-spacing:.006em}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.02em}
.eyebrow{
  display:block;
  font-family:var(--font-mono);
  font-size:12px;
  line-height:1.6;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--amber);
}
.lede{
  font-size:17px;
  line-height:1.85;
  color:var(--paper);
  opacity:.88;
  max-width:40em;
}
.muted{color:var(--mist);opacity:.8}

/* 4. 布局 ------------------------------------------------------------------ */
.container{width:100%;max-width:var(--w-max);margin-inline:auto;padding-inline:var(--gap)}
.section{padding-block:clamp(36px,5vw,56px)}
.stack > * + *{margin-top:20px}
.measure{max-width:36em}
.rule{height:1px;border:0;background:var(--ink-line);margin-block:clamp(24px,4vw,40px)}
.grid{display:grid;gap:clamp(18px,2.6vw,28px)}
.grid--sidebar{grid-template-columns:minmax(0,1fr)}
.sidebar-col,.main-col{min-width:0}
@media (min-width:1024px){
  .grid--sidebar{grid-template-columns:232px minmax(0,1fr);gap:0}
  .grid--sidebar > .sidebar-col{padding-right:24px;border-right:1px solid var(--ink-line)}
  .grid--sidebar > .main-col{padding-left:32px}
}
.surface-paper{
  background:var(--paper);
  color:var(--obsidian);
  padding:clamp(22px,3.4vw,36px);
  border-radius:2px;
}
.surface-paper a{color:var(--obsidian);border-bottom:1px solid var(--amber)}
.surface-paper a:hover{color:var(--obsidian);border-bottom-color:var(--obsidian)}
.surface-paper .muted{color:var(--grayblue);opacity:.9}

/* 5. 头部外壳 -------------------------------------------------------------- */
.skip-link{
  position:absolute;
  left:12px;
  top:-64px;
  z-index:120;
  padding:10px 16px;
  background:var(--amber);
  color:var(--obsidian);
  font-size:14px;
  font-weight:500;
  border-radius:2px;
  transition:top .18s ease;
}
.skip-link:focus{top:12px;color:var(--obsidian)}

.site-header{
  position:sticky;
  top:0;
  z-index:60;
  background:rgba(11,14,19,.94);
  border-bottom:1px solid var(--ink-line);
}
.site-header__inner{
  max-width:var(--w-max);
  margin-inline:auto;
  padding-inline:var(--gap);
  min-height:var(--header-h);
  display:grid;
  grid-template-columns:auto minmax(0,1fr) auto;
  align-items:center;
  gap:clamp(16px,3vw,48px);
}

/* 品牌块 */
.brand-block{display:flex;flex-direction:column;justify-content:center;min-width:0}
.brand{display:inline-flex;align-items:baseline;gap:10px}
.brand__name{
  font-family:var(--font-display);
  font-weight:700;
  font-size:19px;
  letter-spacing:.02em;
  color:var(--paper);
}
.brand:hover .brand__name{color:var(--gold)}
.brand__version{
  font-size:12.5px;
  line-height:1;
  color:var(--gold);
  background:rgba(217,164,65,.1);
  border:1px solid rgba(217,164,65,.45);
  border-radius:2px;
  padding:3px 7px;
}
.brand__meta{
  display:flex;
  align-items:center;
  gap:12px;
  margin-top:5px;
  font-size:11.5px;
  letter-spacing:.04em;
  color:var(--mist);
}
.brand__status{display:inline-flex;align-items:center;gap:6px;color:var(--celadon)}
.brand__status::before{content:"";width:6px;height:6px;background:var(--celadon);flex:none}

/* 中部刻度尺 */
.header-ruler{align-self:end;display:flex;flex-direction:column;gap:7px;padding-bottom:24px;min-width:0}
.header-ruler__label{font-size:10px;letter-spacing:.24em;color:var(--mist);opacity:.55;white-space:nowrap}
.header-ruler__ticks{
  display:block;
  height:9px;
  border-bottom:1px solid var(--ink-line);
  background-image:repeating-linear-gradient(to right,var(--ink-line) 0 1px,transparent 1px 16px);
}

/* 导航 */
.header-nav{display:flex;align-items:center;gap:18px}
.site-nav{display:flex;align-items:center;gap:28px}
.site-nav__list{display:flex;flex-wrap:wrap;align-items:center;justify-content:flex-end;gap:26px}
.site-nav__link{
  position:relative;
  display:inline-block;
  padding:6px 0;
  font-size:15px;
  color:var(--mist);
  transition:color .18s ease;
}
.site-nav__link::after{
  content:"";
  position:absolute;
  left:0;right:0;bottom:0;
  height:2px;
  background:var(--amber);
  transform:scaleX(0);
  transform-origin:left center;
  transition:transform .18s ease;
}
.site-nav__link:hover{color:var(--gold)}
.site-nav__link:hover::after{transform:scaleX(1)}
.site-nav__link[aria-current="page"]{color:var(--paper)}
.site-nav__link[aria-current="page"]::after{transform:scaleX(1)}
.site-nav__utility{
  font-size:14px;
  color:var(--amber);
  padding-bottom:2px;
  border-bottom:1px solid rgba(217,164,65,.5);
  white-space:nowrap;
}
.site-nav__utility:hover{color:var(--gold);border-bottom-color:var(--gold)}
.nav-toggle{display:none}

/* 6. 页脚 ------------------------------------------------------------------ */
.site-footer{position:relative;margin-top:clamp(48px,7vw,96px);background:var(--carbon);border-top:1px solid var(--ink-line)}
.site-footer::before{content:"";position:absolute;top:0;left:0;width:min(240px,40%);height:2px;background:var(--amber)}
.site-footer__inner{max-width:var(--w-max);margin-inline:auto;padding:clamp(40px,5vw,64px) var(--gap) 24px}
.footer-grid{display:grid;gap:clamp(24px,3vw,40px);grid-template-columns:minmax(0,1fr)}
@media (min-width:640px){.footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (min-width:1024px){
  .footer-grid{grid-template-columns:1.5fr 1fr 1fr 1.35fr}
  .footer-col + .footer-col{padding-left:clamp(20px,2.4vw,32px);border-left:1px solid var(--line-soft)}
}
.footer-col{min-width:0}
.footer-col--brand{padding-bottom:6px}
.footer-col--contact{padding-bottom:6px}
.footer-col__title{
  font-family:var(--font-mono);
  font-size:11.5px;
  font-weight:500;
  letter-spacing:.2em;
  text-transform:uppercase;
  color:var(--amber);
  margin-bottom:14px;
}
.footer-brand{font-family:var(--font-display);font-weight:700;font-size:20px;letter-spacing:.02em;color:var(--paper)}
.footer-version{margin-top:9px;font-size:12.5px;color:var(--mist)}
.footer-note{margin-top:14px;font-size:13.5px;line-height:1.7;color:var(--mist);max-width:34em}
.footer-list{display:grid;gap:9px;font-size:14.5px;line-height:1.6}
.footer-list a{color:var(--mist);transition:color .18s ease}
.footer-list a:hover{color:var(--gold)}
.footer-list--contact{font-size:14px;color:var(--mist)}
.footer-list--contact .mono{display:inline-block;min-width:3.2em;margin-right:8px;font-size:11px;letter-spacing:.12em;color:var(--amber)}
.footer-bottom{
  margin-top:clamp(28px,4vw,48px);
  padding-top:18px;
  border-top:1px solid var(--line-soft);
  display:flex;
  flex-wrap:wrap;
  justify-content:center;
  gap:8px 28px;
  text-align:center;
}
.footer-bottom__line{font-family:var(--font-mono);font-size:12px;letter-spacing:.04em;color:var(--mist)}

/* 7. 按钮与链接 ------------------------------------------------------------ */
.btn{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:11px 20px;
  border:1px solid var(--ink-line);
  border-radius:2px;
  background:var(--carbon);
  color:var(--paper);
  font-size:15px;
  font-weight:500;
  letter-spacing:.02em;
  transition:border-color .18s ease,transform .18s ease,background-color .18s ease,color .18s ease;
}
.btn:hover{border-color:var(--amber);color:var(--gold);transform:translateY(-2px)}
.btn--primary{background:var(--amber);border-color:var(--amber);color:var(--obsidian)}
.btn--primary:hover{background:var(--gold);border-color:var(--gold);color:var(--obsidian)}
.btn--ghost{background:transparent}
.btn-row{display:flex;flex-wrap:wrap;gap:12px;margin-top:24px}
.link-underline{position:relative;color:var(--gold)}
.link-underline::after{
  content:"";
  position:absolute;
  left:0;right:0;bottom:-2px;
  height:1px;
  background:currentColor;
  transform:scaleX(0);
  transform-origin:left center;
  transition:transform .18s ease;
}
.link-underline:hover::after{transform:scaleX(1)}

/* 8. 状态与标签 ------------------------------------------------------------ */
.status{display:inline-flex;align-items:center;gap:7px;font-family:var(--font-mono);font-size:12px;letter-spacing:.06em}
.status::before{content:"";width:7px;height:7px;background:currentColor;flex:none}
.status--ok{color:var(--celadon)}
.status--warn{color:var(--signal)}
.status--idle{color:var(--mist)}
.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:3px 9px;
  border:1px solid var(--ink-line);
  border-radius:2px;
  background:rgba(38,50,68,.5);
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.06em;
  color:var(--mist);
}

/* 9. 信息面板 -------------------------------------------------------------- */
.panel{
  position:relative;
  background:var(--carbon);
  border:1px solid var(--ink-line);
  border-radius:2px;
  padding:24px;
  transition:border-color .18s ease,transform .18s ease;
}
.panel:hover{border-color:var(--amber);transform:translateY(-2px)}
.panel--flat:hover{border-color:var(--ink-line);transform:none}
.panel__index{
  position:absolute;
  top:-1px;right:-1px;
  padding:3px 9px;
  background:var(--amber);
  color:var(--obsidian);
  font-family:var(--font-mono);
  font-size:11px;
  letter-spacing:.12em;
}
.panel__title{font-family:var(--font-serif);font-size:20px;font-weight:500;color:var(--paper);margin-bottom:10px}
.panel__body{font-size:15.5px;color:var(--mist)}

/* 10. 对照条 --------------------------------------------------------------- */
.compare-strip{
  display:grid;
  grid-template-columns:minmax(0,1fr);
  border:1px solid var(--ink-line);
  border-radius:2px;
  background:var(--carbon);
  overflow:hidden;
}
.compare-strip__side{padding:clamp(18px,2.6vw,26px);transition:opacity .2s ease}
.compare-strip__side + .compare-strip__side{border-top:1px solid var(--ink-line)}
@media (min-width:768px){
  .compare-strip{grid-template-columns:repeat(2,minmax(0,1fr))}
  .compare-strip__side + .compare-strip__side{border-top:0;border-left:1px solid var(--ink-line)}
}
.compare-strip:hover .compare-strip__side{opacity:.72}
.compare-strip .compare-strip__side:hover{opacity:1}
.compare-strip--paper{background:var(--paper);border-color:rgba(11,14,19,.16);color:var(--obsidian)}
.compare-strip--paper .compare-strip__side + .compare-strip__side{border-color:rgba(11,14,19,.14)}
.compare-strip--paper h2,.compare-strip--paper h3,.compare-strip--paper .panel__title{color:var(--obsidian)}

/* 11. 数据表 --------------------------------------------------------------- */
.table-scroll{overflow-x:auto;border:1px solid var(--ink-line);border-radius:2px;background:var(--carbon)}
.data-table{min-width:560px;font-size:15px}
.data-table caption{
  padding:12px 16px;
  text-align:left;
  border-bottom:1px solid var(--line-soft);
  font-family:var(--font-mono);
  font-size:12.5px;
  letter-spacing:.06em;
  color:var(--mist);
}
.data-table th,.data-table td{padding:12px 16px;text-align:left;vertical-align:top;border-bottom:1px solid var(--line-soft)}
.data-table thead th{
  background:var(--grayblue);
  color:var(--paper);
  font-family:var(--font-mono);
  font-size:12.5px;
  font-weight:500;
  letter-spacing:.08em;
  white-space:nowrap;
}
.data-table tbody tr:hover{background:rgba(38,50,68,.45)}
.data-table tbody tr:last-child th,.data-table tbody tr:last-child td{border-bottom:0}

/* 12. 图片容器基础规则 ----------------------------------------------------- */
.figure{display:block;margin:0}
.figure__frame{
  position:relative;
  aspect-ratio:16 / 9;
  overflow:hidden;
  border:1px solid var(--ink-line);
  border-radius:2px;
  background-color:var(--grayblue);
  background-image:repeating-linear-gradient(to right,rgba(169,180,196,.1) 0 1px,transparent 1px 26px);
}
.figure__frame--wide{aspect-ratio:21 / 9}
.figure__frame--portrait{aspect-ratio:4 / 5}
.figure__img,.figure__frame > img{width:100%;height:100%;object-fit:cover}
.figure__frame::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  opacity:0;
  background-color:rgba(11,14,19,.28);
  border:1px solid var(--amber);
  transition:opacity .18s ease;
}
.figure:hover .figure__frame::after{opacity:1}
.figure__cap{margin-top:10px;font-size:13px;letter-spacing:.02em;color:var(--mist)}

/* 13. 折叠问答 ------------------------------------------------------------- */
.disclosure{border:1px solid var(--ink-line);border-radius:2px;background:var(--carbon)}
.disclosure + .disclosure{margin-top:10px}
.disclosure__summary{
  display:flex;
  align-items:center;
  gap:12px;
  padding:16px 20px;
  font-size:16px;
  font-weight:500;
  color:var(--paper);
  cursor:pointer;
  list-style:none;
  transition:color .18s ease;
}
.disclosure__summary::-webkit-details-marker{display:none}
.disclosure__summary::after{content:"+";margin-left:auto;font-family:var(--font-mono);color:var(--amber)}
.disclosure[open] .disclosure__summary{color:var(--gold);border-bottom:1px solid var(--line-soft)}
.disclosure[open] .disclosure__summary::after{content:"−"}
.disclosure__body{padding:18px 20px 22px;font-size:15.5px;color:var(--mist)}

/* 14. 时间轴 --------------------------------------------------------------- */
.timeline{margin:0}
.timeline__list{margin:0;padding:0}
.timeline__item{position:relative;padding:0 0 30px 26px;border-left:1px solid var(--ink-line)}
.timeline__item:last-child{padding-bottom:0;border-left-color:transparent}
.timeline__node{
  position:absolute;
  left:-5px;
  top:7px;
  width:9px;height:9px;
  background:var(--obsidian);
  border:1px solid var(--amber);
  transition:background-color .18s ease,box-shadow .18s ease,border-color .18s ease;
}
.timeline__item:hover .timeline__node{background:var(--gold);border-color:var(--gold);box-shadow:0 0 0 3px rgba(255,217,138,.16)}
.timeline__date{display:block;margin-bottom:4px;font-family:var(--font-mono);font-size:12.5px;letter-spacing:.06em;color:var(--amber)}
.timeline__title{font-family:var(--font-serif);font-size:18px;font-weight:500;color:var(--paper)}

/* 15. 面包屑与侧栏锚点 ----------------------------------------------------- */
.breadcrumb{margin:0 0 24px}
.breadcrumb__list{display:flex;flex-wrap:wrap;align-items:center;gap:8px;font-family:var(--font-mono);font-size:12.5px;letter-spacing:.04em;color:var(--mist)}
.breadcrumb__item + .breadcrumb__item::before{content:"/";color:var(--ink-line);margin-right:8px}
.breadcrumb__link{color:var(--mist)}
.breadcrumb__link:hover{color:var(--gold)}
.breadcrumb__item[aria-current="page"]{color:var(--paper)}

.spy-link{
  position:relative;
  display:block;
  padding:9px 12px;
  border-left:1px solid var(--ink-line);
  font-family:var(--font-mono);
  font-size:12.5px;
  letter-spacing:.04em;
  color:var(--mist);
  transition:color .18s ease,background-color .18s ease,border-color .18s ease;
}
.spy-link:hover{color:var(--gold);background:rgba(38,50,68,.6)}
.spy-link.is-active{color:var(--paper);background:var(--grayblue);border-left-color:var(--amber)}
.spy-link.is-active::before{content:"";position:absolute;left:-1px;top:0;bottom:0;width:2px;background:var(--amber)}
.spy-section{scroll-margin-top:calc(var(--header-h) + 20px)}

/* 16. 滚动进度与显现 ------------------------------------------------------- */
.scroll-progress{
  position:fixed;
  top:0;left:0;right:0;
  height:2px;
  z-index:90;
  pointer-events:none;
  background:linear-gradient(90deg,var(--amber),var(--gold));
  transform:scaleX(0);
  transform-origin:left center;
  transition:transform .08s linear;
}
html.js [data-reveal]{opacity:0;transform:translateY(14px);transition:opacity .5s ease,transform .5s ease}
html.js [data-reveal].is-visible{opacity:1;transform:none}

/* 17. 响应式头部与移动导航 ------------------------------------------------ */
@media (max-width:1140px){
  .header-ruler{display:none}
}
@media (max-width:980px){
  :root{--header-h:64px}
  body{padding-bottom:64px}
  .site-header__inner{grid-template-columns:minmax(0,1fr) auto;gap:12px}
  .header-nav{justify-content:flex-end;gap:0}
  .brand__name{font-size:17px}
  .brand__meta{font-size:11px}
  .nav-toggle{
    display:inline-flex;
    align-items:center;
    gap:9px;
    padding:8px 12px;
    border:1px solid var(--ink-line);
    border-radius:2px;
    background:var(--carbon);
    color:var(--paper);
    font-size:14px;
    transition:border-color .18s ease,color .18s ease;
  }
  .nav-toggle:hover{border-color:var(--amber);color:var(--gold)}
  .nav-toggle__label{letter-spacing:.04em}
  .nav-toggle__mark{display:inline-block;width:14px;height:8px;border-top:1px solid currentColor;border-bottom:1px solid currentColor}
  .nav-toggle[aria-expanded="true"]{border-color:var(--amber);color:var(--gold)}
  .nav-toggle[aria-expanded="true"] .nav-toggle__mark{border-top-color:var(--amber);border-bottom-color:var(--amber)}

  .site-nav{
    position:fixed;
    left:0;right:0;bottom:0;
    z-index:75;
    display:block;
    background:var(--carbon);
    border-top:1px solid var(--ink-line);
    box-shadow:0 -10px 28px rgba(0,0,0,.45);
    padding:8px 10px calc(8px + env(safe-area-inset-bottom,0px));
  }
  .site-nav__list{
    display:flex;
    flex-wrap:nowrap;
    justify-content:flex-start;
    gap:4px;
    overflow-x:auto;
    scrollbar-width:none;
    -webkit-overflow-scrolling:touch;
  }
  .site-nav__list::-webkit-scrollbar{display:none}
  .site-nav__link{
    padding:8px 10px;
    font-size:14px;
    white-space:nowrap;
    border:1px solid transparent;
    border-radius:2px;
  }
  .site-nav__link::after{display:none}
  .site-nav__link[aria-current="page"]{color:var(--gold);border-color:rgba(217,164,65,.5);background:rgba(217,164,65,.08)}
  .site-nav__utility{display:none}
  .site-nav[data-open]{padding-bottom:calc(14px + env(safe-area-inset-bottom,0px))}
  .site-nav[data-open] .site-nav__list{flex-wrap:wrap;overflow:visible}
  .site-nav[data-open] .site-nav__link{flex:1 1 42%;border-color:var(--ink-line);background:var(--obsidian);text-align:center}
  .site-nav[data-open] .site-nav__link[aria-current="page"]{border-color:rgba(217,164,65,.5);background:rgba(217,164,65,.1)}
  .site-nav[data-open] .site-nav__utility{display:inline-block;margin:14px 10px 4px;font-size:14px}
  html[data-nav-open]::before{
    content:"";
    position:fixed;
    inset:0;
    z-index:70;
    background:rgba(11,14,19,.6);
  }
}

/* 18. 减弱动效 ------------------------------------------------------------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  html.js [data-reveal]{opacity:1;transform:none}
  .scroll-progress{transition:none}
  .panel:hover,.btn:hover,.compare-strip:hover .compare-strip__side{transform:none}
}