/* ============================================================
   视讯厅会馆 · 共享站点样式  /assets/site.css
   墨蓝夜色 + 沙金灯线 + 胡杨橙落点 + 青绿路径
   ============================================================ */

/* 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,ul,ol,figure,blockquote,dl,dd{margin:0}
ul,ol{padding:0;list-style:none}
img,svg{display:block;max-width:100%}
button{font:inherit;color:inherit;background:none;border:0;padding:0}
a{color:inherit}
table{border-collapse:collapse;width:100%}
[hidden]{display:none !important}

/* 2. 变量 */
:root{
  --ink:#0E1E33;
  --ink-deep:#071322;
  --ink-soft:#132A44;
  --sand:#D6B15C;
  --sand-pale:#EFD9A3;
  --poplar:#E2651E;
  --jade:#2FA98C;
  --cream:#F5EDDC;
  --paper:#FDF9F1;
  --graphite:#2A2A2A;
  --mist:#93A7BC;
  --line:rgba(214,177,92,.26);
  --line-strong:rgba(214,177,92,.52);
  --unit:24px;
  --radius:3px;
  --shell:1240px;
  --font-hei:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Source Han Sans SC","Noto Sans CJK SC","Heiti SC",sans-serif;
  --font-song:"Songti SC","Source Han Serif SC","Noto Serif CJK SC","SimSun",serif;
  --font-mono:ui-monospace,"SFMono-Regular","IBM Plex Mono","Noto Sans Mono",Menlo,Consolas,monospace;
}

/* 3. 基础元素 */
body{
  background:var(--ink);
  color:var(--cream);
  font-family:var(--font-hei);
  font-size:16.5px;
  line-height:1.85;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
h1,h2,h3,h4,h5{font-weight:800;line-height:1.2;letter-spacing:-.01em;color:var(--cream)}
h1{font-size:clamp(32px,4.6vw,56px);line-height:1.1}
h2{font-size:clamp(24px,2.8vw,36px)}
h3{font-size:clamp(19px,2vw,24px)}
strong{color:var(--sand-pale);font-weight:700}
em{font-style:normal;color:var(--sand)}
a{color:var(--sand-pale);text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:3px;transition:color .2s ease-out}
a:hover{color:var(--sand)}
::selection{background:rgba(226,101,30,.4);color:#FFF9F1}
:focus-visible{outline:2px solid var(--sand);outline-offset:3px;border-radius:2px}
body.nav-is-open{overflow:hidden}

/* 4. 工具类与布局 */
.container{width:100%;max-width:var(--shell);margin-inline:auto;padding-inline:clamp(20px,4.5vw,48px)}
.visually-hidden{position:absolute !important;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}
.rule{height:1px;border:0;background:var(--line);margin:0}
.section{position:relative;padding-block:clamp(52px,7vw,104px)}
.section--paper{background:var(--cream);color:var(--graphite)}
.section--paper h1,.section--paper h2,.section--paper h3,.section--paper h4{color:var(--ink)}
.section--paper .eyebrow{color:#9A6118}
.section--paper .lede{color:#57472F}
.section--paper .mono-note{color:#7B6A50}
.section--paper .rule{background:rgba(42,42,42,.16)}
.section-head{
  display:grid;
  grid-template-columns:minmax(0,7fr) minmax(0,4fr);
  gap:clamp(16px,3vw,48px);
  align-items:end;
  margin-bottom:clamp(24px,3.5vw,48px);
}
.grid{display:grid;gap:var(--unit);grid-template-columns:repeat(12,minmax(0,1fr))}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-side{grid-template-columns:88px minmax(0,1fr);gap:clamp(16px,3vw,40px)}

/* 5. 头部 */
.skip-link{
  position:fixed;top:10px;left:10px;z-index:200;
  transform:translateY(-180%);
  background:var(--poplar);color:#FFF4EA;
  padding:10px 18px;border-radius:2px;
  font-size:13px;font-weight:700;letter-spacing:.06em;text-decoration:none;
  transition:transform .2s ease-out;
}
.skip-link:focus{transform:translateY(0);color:#FFF4EA}

.site-header{
  position:sticky;top:0;z-index:90;
  background:
    radial-gradient(92% 220% at 6% -90%,rgba(214,177,92,.20),transparent 62%),
    linear-gradient(180deg,#12283F 0%,#0E1E33 74%);
  border-bottom:1px solid var(--line);
  color:var(--cream);
}
.site-header::before{
  content:"";position:absolute;inset:0;pointer-events:none;opacity:.5;
  background-image:repeating-linear-gradient(90deg,rgba(214,177,92,.10) 0 1px,transparent 1px 92px);
}
.scroll-meter{position:absolute;left:0;right:0;bottom:-1px;height:2px;background:rgba(147,167,188,.16);pointer-events:none}
.scroll-meter-fill{
  display:block;height:100%;width:100%;
  background:linear-gradient(90deg,var(--jade),var(--sand) 56%,var(--poplar));
  transform:scaleX(0);transform-origin:0 50%;
  transition:transform .12s linear;
}
.header-inner{
  position:relative;z-index:3;
  display:flex;align-items:center;
  gap:clamp(16px,3vw,40px);
  min-height:96px;padding-block:16px;
  transition:min-height .24s ease-out,padding .24s ease-out;
}
.brand{flex:0 1 auto;min-width:0}
.brand-link{display:inline-flex;align-items:center;gap:14px;text-decoration:none;color:var(--cream)}
.brand-link:hover{color:var(--cream)}
.brand-seal{
  flex:none;display:grid;place-items:center;
  width:44px;height:44px;
  border:1px solid var(--line-strong);
  background:linear-gradient(150deg,rgba(214,177,92,.22),rgba(214,177,92,.02));
  color:var(--sand);font-size:19px;font-weight:700;line-height:1;
  transform:rotate(-4deg);
  transition:transform .24s ease-out,width .24s ease-out,height .24s ease-out;
}
.brand-link:hover .brand-seal{transform:rotate(0deg)}
.brand-text{display:flex;flex-direction:column;gap:3px;min-width:0}
.brand-name{font-size:22px;font-weight:800;letter-spacing:.1em;line-height:1.15;white-space:nowrap}
.brand-domain{font-family:var(--font-mono);font-size:10.5px;letter-spacing:.16em;color:var(--mist);line-height:1.4;white-space:nowrap}

.site-nav{
  margin-left:auto;
  display:flex;align-items:flex-start;
  gap:clamp(24px,3.4vw,60px);
  padding-top:2px;
}
.nav-group{display:flex;flex-direction:column;gap:6px;min-width:0}
.nav-group-label{
  display:flex;align-items:center;gap:7px;
  margin:0;
  font-family:var(--font-mono);font-size:10px;letter-spacing:.22em;
  color:var(--sand);line-height:1;
}
.nav-group-label::before{content:"";width:12px;height:1px;background:var(--sand);opacity:.75}
.nav-list{display:flex;align-items:center;gap:clamp(12px,1.5vw,24px)}
.nav-item{display:block}
.nav-link{
  position:relative;display:inline-block;
  padding:6px 0 7px;
  font-size:15px;font-weight:600;letter-spacing:.06em;
  color:var(--cream);text-decoration:none;white-space:nowrap;
  transition:color .2s ease-out;
}
.nav-link::after{
  content:"";position:absolute;left:0;right:0;bottom:0;height:1px;
  background:var(--sand);
  transform:scaleX(0);transform-origin:0 50%;
  transition:transform .24s ease-out;
}
.nav-link:hover,.nav-link:focus-visible{color:var(--sand-pale)}
.nav-link:hover::after,.nav-link:focus-visible::after{transform:scaleX(1)}
.nav-link[aria-current="page"]{color:var(--sand)}
.nav-link[aria-current="page"]::after{transform:scaleX(1);height:2px;background:var(--poplar)}
.header-actions{display:flex;align-items:center;gap:12px;flex:none}
.nav-toggle{
  display:none;align-items:center;gap:9px;
  padding:10px 14px;border-radius:2px;
  border:1px solid var(--line-strong);
  background:rgba(214,177,92,.06);
  color:var(--sand-pale);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.16em;
  cursor:pointer;
  transition:background .2s ease-out,color .2s ease-out,border-color .2s ease-out;
}
.nav-toggle:hover{background:rgba(214,177,92,.16);color:var(--sand);border-color:var(--sand)}
.nav-toggle-icon{position:relative;display:block;width:16px;height:10px}
.nav-toggle-bar{
  position:absolute;left:0;width:16px;height:1.5px;background:currentColor;
  transition:transform .24s ease-out;
}
.nav-toggle-bar:nth-child(1){top:0}
.nav-toggle-bar:nth-child(2){bottom:0}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1){transform:translateY(4.25px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2){transform:translateY(-4.25px) rotate(-45deg)}
.nav-scrim{
  position:fixed;inset:0;z-index:1;
  background:rgba(7,19,34,.74);
  opacity:0;pointer-events:none;
  transition:opacity .24s ease-out;
}
.nav-scrim[data-active="true"]{opacity:1;pointer-events:auto}

/* 6. 页脚 */
.site-footer{
  position:relative;
  background:linear-gradient(180deg,#0B1B2E 0%,#071322 72%);
  color:var(--cream);
  border-top:1px solid var(--line-strong);
  padding-block:clamp(44px,6vw,80px) 0;
}
.site-footer::before{
  content:"";position:absolute;top:0;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,var(--sand),transparent);
  opacity:.65;
}
.footer-grid{
  display:grid;
  grid-template-columns:1.5fr 1fr 1.4fr 1fr;
  gap:clamp(24px,4vw,56px);
}
.footer-col{min-width:0}
.footer-brand-link{display:inline-flex;align-items:center;gap:12px;text-decoration:none;color:var(--cream)}
.footer-brand-link:hover{color:var(--sand-pale)}
.footer-brand-name{font-size:20px;font-weight:800;letter-spacing:.1em;line-height:1.2}
.footer-tagline{
  margin-top:18px;
  font-family:var(--font-song);font-size:15px;line-height:1.9;
  color:var(--mist);max-width:26ch;
}
.footer-col-title{
  font-family:var(--font-mono);font-size:11px;font-weight:500;letter-spacing:.2em;
  color:var(--sand);margin-bottom:16px;line-height:1.4;
}
.footer-list{display:grid;gap:8px}
.footer-link{
  font-size:14.5px;color:#C4D0DE;text-decoration:none;
  transition:color .2s ease-out;
}
.footer-link:hover{color:var(--sand-pale);text-decoration:underline;text-underline-offset:4px}
.footer-contact{display:grid;gap:14px}
.footer-contact-item{display:grid;gap:3px;font-size:14.5px;color:#C4D0DE;line-height:1.7}
.footer-label{font-family:var(--font-mono);font-size:10.5px;letter-spacing:.16em;color:var(--mist)}
.footer-value{color:var(--cream);overflow-wrap:anywhere}
.footer-meta{
  font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;
  color:var(--mist);line-height:1.95;
}
.footer-bottom{
  margin-top:clamp(30px,4vw,56px);
  border-top:1px solid var(--line);
  padding-block:18px 28px;
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  gap:14px 24px;
}
.footer-note{font-size:13px;line-height:1.8;color:var(--mist);max-width:64ch}
.to-top{
  display:inline-flex;align-items:center;gap:8px;
  padding:8px 14px;border:1px solid var(--line);border-radius:2px;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.14em;
  color:var(--sand-pale);cursor:pointer;
  transition:background .2s ease-out,color .2s ease-out,border-color .2s ease-out;
}
.to-top:hover{background:rgba(214,177,92,.12);color:var(--sand);border-color:var(--line-strong)}
.to-top-arrow{font-size:14px;line-height:1}

/* 7. 按钮 */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:12px 22px;border:1px solid transparent;border-radius:2px;
  font-size:14.5px;font-weight:700;letter-spacing:.05em;line-height:1.4;
  text-decoration:none;cursor:pointer;
  transition:background .2s ease-out,color .2s ease-out,border-color .2s ease-out,box-shadow .2s ease-out;
}
.btn-primary{background:var(--poplar);color:#FFF3E8;box-shadow:3px 3px 0 rgba(214,177,92,.26)}
.btn-primary:hover{background:#F07428;color:#FFF9F2;box-shadow:5px 5px 0 rgba(214,177,92,.34)}
.btn-ghost{background:transparent;border-color:var(--line-strong);color:var(--sand-pale)}
.btn-ghost:hover{background:rgba(214,177,92,.12);color:var(--sand);border-color:var(--sand)}
.btn-quiet{
  background:transparent;border-radius:0;padding:8px 0;
  color:var(--jade);border-bottom:1px solid rgba(47,169,140,.5);
}
.btn-quiet:hover{color:#63D2B6}
.nav-cta{margin-top:6px;white-space:nowrap}

/* 8. 排版组件 */
.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  margin-bottom:14px;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.2em;
  color:var(--sand);line-height:1.6;
}
.eyebrow::before{content:"";width:22px;height:1px;background:currentColor}
.display{font-size:clamp(34px,5.4vw,64px);font-weight:800;line-height:1.06;letter-spacing:-.02em}
.lede{
  font-family:var(--font-song);
  font-size:clamp(16px,1.6vw,18.5px);line-height:1.9;
  color:var(--sand-pale);max-width:34em;
}
.mono-note{font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--mist);line-height:1.85}
.prose{max-width:70ch;font-size:16.5px;line-height:1.9}
.prose > *:last-child{margin-bottom:0}
.prose p{margin-bottom:1.05em}
.prose h2{font-size:clamp(22px,2.4vw,28px);margin:1.6em 0 .6em}
.prose h3{font-size:19px;margin:1.4em 0 .5em}
.prose ul{display:grid;gap:8px;margin:0 0 1.05em}
.prose ul li{position:relative;padding-left:18px}
.prose ul li::before{content:"";position:absolute;left:0;top:.8em;width:7px;height:1px;background:var(--sand)}

/* 9. 卡片、标签、档案叠层 */
.card{
  position:relative;display:block;
  padding:clamp(20px,2.4vw,30px);
  border:1px solid var(--line);border-radius:var(--radius);
  background:linear-gradient(160deg,rgba(19,42,68,.94),rgba(10,25,42,.94));
  color:var(--cream);text-decoration:none;
  transition:transform .24s ease-out,box-shadow .24s ease-out,border-color .24s ease-out;
}
.card:hover,.card:focus-visible{
  transform:translateY(-4px);
  border-color:var(--line-strong);
  box-shadow:0 16px 34px rgba(7,19,34,.55);
  color:var(--cream);
}
.card-title{font-size:22px;font-weight:800;line-height:1.32;margin-bottom:8px;color:var(--sand-pale)}
.card-text{font-size:15px;line-height:1.8;color:#B7C5D4;max-width:46ch}
.card-meta{margin-top:16px;font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;color:var(--jade)}
.card-paper{
  background:var(--paper);border-color:rgba(42,42,42,.16);
  color:var(--graphite);box-shadow:0 12px 28px rgba(7,19,34,.16);
}
.card-paper:hover,.card-paper:focus-visible{color:var(--graphite);box-shadow:0 20px 38px rgba(7,19,34,.24)}
.card-paper .card-title{color:var(--ink)}
.card-paper .card-text{color:#4C4C4C}
.card-paper .card-meta{color:#8A5A18}
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 10px;border-radius:2px;
  border:1px solid var(--line-strong);
  background:rgba(214,177,92,.08);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;color:var(--sand-pale);
}
.tag-jade{color:#7AD9C3;border-color:rgba(47,169,140,.55);background:rgba(47,169,140,.14)}
.tag-poplar{color:#FFC59C;border-color:rgba(226,101,30,.6);background:rgba(226,101,30,.16)}
.paper-stack{position:relative;isolation:isolate}
.paper-stack::before,.paper-stack::after{
  content:"";position:absolute;inset:0;z-index:-1;
  background:var(--paper);border:1px solid rgba(42,42,42,.14);
}
.paper-stack::before{transform:translate(10px,10px) rotate(.6deg)}
.paper-stack::after{transform:translate(20px,20px) rotate(-.5deg);opacity:.72}

/* 10. 面包屑与章节索引 */
.breadcrumb{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;
  color:var(--mist);line-height:1.7;
}
.breadcrumb a{color:var(--sand-pale);text-decoration:none}
.breadcrumb a:hover{color:var(--sand);text-decoration:underline;text-underline-offset:3px}
.breadcrumb-sep{color:rgba(147,167,188,.6)}
.side-index{
  position:sticky;top:112px;align-self:start;
  padding-left:14px;border-left:1px solid var(--line);
}
.side-index-title{
  margin-bottom:12px;
  font-family:var(--font-mono);font-size:10.5px;letter-spacing:.2em;
  color:var(--sand);line-height:1.5;
}
.index-link{
  display:block;margin-left:-16px;padding:6px 0 6px 14px;
  border-left:2px solid transparent;
  font-size:13.5px;line-height:1.6;color:var(--mist);text-decoration:none;
  transition:color .2s ease-out,border-color .24s ease-out;
}
.index-link:hover{color:var(--sand-pale)}
.index-link[aria-current="true"]{color:var(--sand);border-left-color:var(--sand)}

/* 11. 图片容器与提示块 */
.media-frame{
  position:relative;overflow:hidden;isolation:isolate;
  aspect-ratio:16/10;
  border:1px solid var(--line);
  background:linear-gradient(150deg,#132A44,#0A1B2E);
}
.media-frame::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:linear-gradient(180deg,transparent 55%,rgba(7,19,34,.55));
}
.media-frame img{width:100%;height:100%;object-fit:cover}
.media-frame--portrait{aspect-ratio:3/4}
.media-frame--wide{aspect-ratio:21/9}
.media-caption{margin-top:10px;font-family:var(--font-mono);font-size:11.5px;letter-spacing:.06em;color:var(--mist)}
.callout{
  padding:18px 22px;
  border-left:2px solid var(--jade);
  background:rgba(47,169,140,.09);
  color:#CFE6DF;font-size:15px;line-height:1.85;
}
.callout strong{color:#9DE6D3}

/* 12. 显现动效 */
.has-js [data-reveal]{
  opacity:0;transform:translateY(12px);
  transition:opacity .5s ease-out,transform .5s ease-out;
}
.has-js [data-reveal].is-revealed{opacity:1;transform:none}

/* 13. 平板与手机 */
@media (max-width:1024px){
  .footer-grid{grid-template-columns:1fr 1fr;gap:32px 28px}
}
@media (max-width:900px){
  body{font-size:16px}
  .header-inner{min-height:64px;padding-block:12px;gap:12px}
  .brand-seal{width:36px;height:36px;font-size:16px}
  .brand-name{font-size:18px;letter-spacing:.08em}
  .brand-domain{display:none}
  .header-actions{margin-left:auto}
  .nav-toggle{display:inline-flex}
  .nav-scrim{display:block}
  .site-nav{
    position:fixed;left:0;right:0;bottom:0;top:auto;z-index:2;
    margin:0;
    padding:22px clamp(18px,5vw,28px) calc(22px + env(safe-area-inset-bottom));
    display:grid;grid-template-columns:1fr 1fr;gap:22px 16px;
    max-height:82vh;overflow-y:auto;
    background:linear-gradient(180deg,#12283F 0%,#071322 88%);
    border-top:1px solid var(--line-strong);
    box-shadow:0 -22px 48px rgba(7,19,34,.62);
    transform:translateY(106%);
    transition:transform .3s cubic-bezier(.32,.72,.24,1);
    will-change:transform;
  }
  .site-nav[data-open="true"]{transform:translateY(0)}
  .nav-group{gap:10px}
  .nav-group-label{font-size:11px;letter-spacing:.2em}
  .nav-list{flex-direction:column;align-items:stretch;gap:2px}
  .nav-link{
    display:block;padding:10px 0;font-size:16px;
    border-bottom:1px solid rgba(214,177,92,.14);
  }
  .nav-link::after{display:none}
  .nav-link[aria-current="page"]::before{
    content:"";position:absolute;left:-10px;top:50%;
    width:6px;height:6px;background:var(--poplar);
    transform:translateY(-50%) rotate(45deg);
  }
  .nav-cta{grid-column:1 / -1;justify-content:center;margin-top:6px;width:100%}
  .grid,.grid-2,.grid-3,.grid-side{grid-template-columns:1fr}
  .section-head{grid-template-columns:1fr;align-items:start}
  .side-index{position:static;border-left:0;padding-left:0;border-top:1px solid var(--line);padding-top:14px}
  .index-link{margin-left:0;padding-left:12px;border-left:2px solid transparent}
}
@media (max-width:600px){
  .footer-grid{grid-template-columns:1fr}
  .footer-bottom{flex-direction:column;align-items:flex-start}
  .to-top{align-self:stretch;justify-content:center}
  .display{font-size:clamp(30px,8vw,40px)}
}

/* 14. 桌面端吸附压缩 */
@media (min-width:901px){
  .site-header[data-stuck="true"] .header-inner{min-height:66px;padding-block:10px}
  .site-header[data-stuck="true"] .brand-seal{width:34px;height:34px;font-size:15px;transform:rotate(-4deg)}
  .site-header[data-stuck="true"] .brand-name{font-size:17px}
  .site-header[data-stuck="true"] .brand-domain{display:none}
  .site-header[data-stuck="true"] .site-nav{align-items:center;gap:clamp(18px,2.4vw,40px)}
  .site-header[data-stuck="true"] .nav-group-label{display:none}
  .site-header[data-stuck="true"] .nav-link{font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;padding-block:4px}
  .site-header[data-stuck="true"] .nav-cta{margin-top:0;padding:8px 16px;font-size:12px;align-self:center}
}

/* 15. 降低动效 */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  .has-js [data-reveal]{opacity:1 !important;transform:none !important}
  .card:hover,.card:focus-visible{transform:none}
  .brand-seal,.brand-link:hover .brand-seal{transform:none}
}