/* ==========================================================
   华体主页 · 全站共享样式 /assets/site.css
   目录：1 变量 2 重置 3 基础排版 4 通用组件 5 头部侧栏
        6 页脚 7 响应式与无障碍
   ========================================================== */

/* ---------- 1. 变量 ---------- */
:root{
  --ink:#0B1233;
  --ink-2:#16224F;
  --violet:#6C3CE9;
  --violet-deep:#3F1F9E;
  --cyan:#22E0D6;
  --orange:#FF7A2F;
  --moss:#4C7A5A;
  --clay:#C2694A;
  --stone:#8A93A3;
  --bone:#F4F1EA;
  --text-dark:#12172A;

  --rail-w:264px;
  --top-h:64px;

  --line:rgba(138,147,163,.22);
  --line-strong:rgba(138,147,163,.42);

  --font-sans:"PingFang SC","Hiragino Sans GB","Microsoft YaHei","Noto Sans CJK SC",system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --font-mono:ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono","Courier New",monospace;

  --ease:cubic-bezier(.22,.61,.36,1);
  --dur:.2s;
  --r-sm:8px;
  --r-md:12px;
  --r-lg:18px;
  --shadow:0 18px 44px rgba(4,7,22,.5);
}

/* ---------- 2. 重置 ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:calc(var(--top-h) + 16px)}
:where(h1,h2,h3,h4,h5,p,ul,ol,figure,blockquote,dl,dd){margin:0}
:where(ul,ol){padding:0}
img,svg,video{display:block;max-width:100%}
img{height:auto}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;cursor:pointer}
a{color:inherit}
table{border-collapse:collapse;width:100%}
hr{border:0;border-top:1px solid var(--line);margin:0}
[hidden]{display:none !important}

/* ---------- 3. 基础排版 ---------- */
body{
  margin:0;
  min-height:100vh;
  font-family:var(--font-sans);
  font-size:16px;
  line-height:1.8;
  font-weight:400;
  color:var(--bone);
  background:var(--ink);
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  padding-top:var(--top-h);
}
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px;border-radius:4px}

h1,h2,h3,h4{line-height:1.25;font-weight:800;letter-spacing:-.005em}
.display-1{font-size:clamp(38px,7.4vw,88px);line-height:1.05;font-weight:800;letter-spacing:-.01em}
.display-2{font-size:clamp(28px,4.4vw,52px);line-height:1.12;font-weight:800;letter-spacing:-.01em}
.lede{font-size:clamp(16px,1.5vw,18px);line-height:1.85;color:rgba(244,241,234,.82);max-width:38em}
.eyebrow{
  display:inline-block;
  font-family:var(--font-mono);
  font-size:12px;
  letter-spacing:.2em;
  text-transform:uppercase;
  color:var(--cyan);
}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.02em}
.muted{color:var(--stone)}
a.link{color:var(--cyan);text-decoration:underline;text-underline-offset:3px;text-decoration-thickness:1px}
a.link:hover{color:var(--bone)}

/* ---------- 4. 通用组件 ---------- */
.wrap{width:100%;max-width:1180px;margin:0 auto;padding:0 20px}

.skip-link{
  position:absolute;top:-64px;left:16px;z-index:400;
  padding:10px 18px;
  background:var(--cyan);color:var(--ink);
  font-size:14px;font-weight:800;letter-spacing:.04em;
  text-decoration:none;border-radius:0 0 var(--r-sm) var(--r-sm);
  transition:top var(--dur) var(--ease);
}
.skip-link:focus{top:0}

.skip-link:focus-visible{outline-offset:0}

.band{padding:56px 0;position:relative}
.band--ink2{background:var(--ink-2)}
.band--bone{background:var(--bone);color:var(--text-dark)}
.band--bone .eyebrow{color:var(--violet-deep)}
.band--bone .lede,.band--bone .muted{color:rgba(18,23,42,.72)}
.band--violet{background:linear-gradient(140deg,var(--violet-deep),var(--violet) 78%)}
.band--bone a.link{color:var(--violet-deep)}

.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 18px;
  border:1px solid transparent;border-radius:var(--r-sm);
  font-family:var(--font-sans);
  font-size:14.5px;font-weight:700;line-height:1.2;letter-spacing:.02em;
  text-decoration:none;text-align:center;white-space:nowrap;
  transition:background-color var(--dur) var(--ease),color var(--dur) var(--ease),
             border-color var(--dur) var(--ease),transform var(--dur) var(--ease),
             box-shadow var(--dur) var(--ease);
}
.btn:active{transform:translateY(1px)}
.btn--primary{background:var(--orange);color:#1A0C02;box-shadow:0 8px 22px rgba(255,122,47,.26)}
.btn--primary:hover{background:#FF9152}
.btn--solid{background:var(--violet);color:var(--bone)}
.btn--solid:hover{background:var(--violet-deep)}
.btn--ghost{background:rgba(244,241,234,.05);color:var(--bone);border-color:var(--line-strong)}
.btn--ghost:hover{border-color:var(--cyan);color:var(--cyan);background:rgba(34,224,214,.09)}
.btn--quiet{background:transparent;color:var(--stone);border-color:var(--line)}
.btn--quiet:hover{color:var(--bone);border-color:var(--stone)}
.btn--block{display:flex;width:100%}
.btn--xs{padding:7px 12px;font-size:12.5px;letter-spacing:.06em}

.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 10px;border-radius:999px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;
  color:var(--stone);background:rgba(244,241,234,.04);
  border:1px solid var(--line-strong);
}
.tag--cyan{color:var(--cyan);border-color:rgba(34,224,214,.45);background:rgba(34,224,214,.09)}
.tag--violet{color:#C7B4FF;border-color:rgba(108,60,233,.6);background:rgba(108,60,233,.18)}
.tag--orange{color:#FFB389;border-color:rgba(255,122,47,.5);background:rgba(255,122,47,.12)}
.tag--moss{color:#9FD4B0;border-color:rgba(76,122,90,.7);background:rgba(76,122,90,.24)}
.tag--clay{color:#EBAE93;border-color:rgba(194,105,74,.6);background:rgba(194,105,74,.2)}

.card{
  position:relative;
  padding:22px;
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  background:linear-gradient(160deg,rgba(22,34,79,.92),rgba(11,18,51,.92));
  transition:border-color var(--dur) var(--ease),transform var(--dur) var(--ease);
}
.card:hover{border-color:rgba(34,224,214,.45);transform:translateY(-2px)}
.card__title{font-size:19px;font-weight:800;line-height:1.4}
.card__meta{margin-top:8px;font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;color:var(--stone)}
.card p{margin-top:12px;font-size:15px;color:rgba(244,241,234,.76)}
.band--bone .card{background:#fff;border-color:rgba(18,23,42,.12);color:var(--text-dark)}
.band--bone .card p{color:rgba(18,23,42,.72)}

.grid{display:grid;gap:20px;grid-template-columns:minmax(0,1fr)}

.breadcrumb{font-family:var(--font-mono);font-size:12px;letter-spacing:.12em;color:var(--stone)}
.breadcrumb ol{display:flex;flex-wrap:wrap;align-items:center;list-style:none;margin:0;padding:0}
.breadcrumb li{display:flex;align-items:center}
.breadcrumb li + li::before{content:"/";margin:0 10px;color:rgba(138,147,163,.55)}
.breadcrumb a{color:var(--stone);text-decoration:none;transition:color var(--dur) var(--ease)}
.breadcrumb a:hover{color:var(--cyan)}
.breadcrumb [aria-current="page"]{color:var(--bone)}

.prose{max-width:38em;font-size:17px;line-height:1.85}
.prose > * + *{margin-top:1.1em}
.prose h2{font-size:clamp(22px,2.4vw,28px);margin-top:2.1em;line-height:1.35}
.prose h3{font-size:20px;margin-top:1.7em}
.prose ul,.prose ol{padding-left:1.25em}
.prose li + li{margin-top:.4em}
.prose strong{font-weight:800}
.prose code{font-family:var(--font-mono);font-size:.92em;padding:2px 6px;border-radius:5px;background:rgba(108,60,233,.22)}
.band--bone .prose{color:var(--text-dark)}
.band--bone .prose code{background:rgba(108,60,233,.12);color:var(--violet-deep)}

.note-box{
  padding:18px 20px;
  border-left:3px solid var(--cyan);
  border-radius:0 var(--r-md) var(--r-md) 0;
  background:rgba(34,224,214,.08);
  font-size:15px;
}
.note-box--warn{border-left-color:var(--orange);background:rgba(255,122,47,.1)}
.note-box--ok{border-left-color:var(--moss);background:rgba(76,122,90,.16)}

.media{
  position:relative;overflow:hidden;
  border:1px solid var(--line);
  border-radius:var(--r-lg);
  background:linear-gradient(140deg,var(--ink-2),var(--ink));
}
.media::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:radial-gradient(90% 70% at 82% 8%,rgba(108,60,233,.42),transparent 62%),
             radial-gradient(70% 60% at 6% 96%,rgba(34,224,214,.18),transparent 60%);
}
.media > img,.media > picture > img,.media > svg{width:100%;height:100%;object-fit:cover}
.media--21x9{aspect-ratio:21/9}
.media--16x9{aspect-ratio:16/9}
.media--4x3{aspect-ratio:4/3}
.media--1x1{aspect-ratio:1/1}

.accordion{border-top:1px solid var(--line)}
.accordion__item{border-bottom:1px solid var(--line)}
.accordion__trigger{
  display:flex;align-items:center;justify-content:space-between;gap:16px;width:100%;
  padding:18px 4px;text-align:left;
  font-size:17px;font-weight:700;color:var(--bone);
  transition:color var(--dur) var(--ease);
}
.accordion__trigger:hover{color:var(--cyan)}
.accordion__trigger::after{
  content:"";flex:0 0 auto;width:10px;height:10px;
  border-right:2px solid var(--cyan);border-bottom:2px solid var(--cyan);
  transform:rotate(45deg);transition:transform var(--dur) var(--ease);
}
.accordion__trigger[aria-expanded="true"]::after{transform:rotate(-135deg)}
.accordion__panel{overflow:hidden;height:auto;transition:height .24s var(--ease)}
.accordion__body{padding:0 4px 20px;font-size:15px;color:var(--stone)}
.accordion__body > * + *{margin-top:.9em}
.band--bone .accordion,.band--bone .accordion__item{border-color:rgba(18,23,42,.14)}
.band--bone .accordion__trigger{color:var(--text-dark)}
.band--bone .accordion__trigger:hover{color:var(--violet-deep)}
.band--bone .accordion__body{color:rgba(18,23,42,.72)}

.scroll-progress{
  position:fixed;top:0;left:0;z-index:320;
  width:0;height:2px;pointer-events:none;
  background:linear-gradient(90deg,var(--cyan),var(--violet) 55%,var(--orange));
}

html.js [data-reveal]{opacity:0;transform:translateY(14px)}
html.js [data-reveal].is-visible{
  opacity:1;transform:none;
  transition:opacity .42s var(--ease),transform .42s var(--ease);
}

/* ---------- 5. 头部与左侧索引栏 ---------- */
.site-header{position:relative;z-index:60}

.rail{
  position:fixed;top:0;left:0;right:0;z-index:60;
  height:var(--top-h);
  display:flex;flex-direction:row;align-items:center;justify-content:space-between;
  padding:0 16px;
  background:linear-gradient(180deg,#0B1233,#101B40);
  border-bottom:1px solid var(--line);
}
.rail__top{display:flex;align-items:center;justify-content:space-between;gap:12px;width:100%}

.rail__brand{display:flex;align-items:center;gap:11px;text-decoration:none;color:var(--bone)}
.rail__brand-mark{
  position:relative;flex:0 0 auto;
  width:32px;height:32px;border-radius:9px;
  background:linear-gradient(140deg,var(--violet),var(--cyan) 78%);
  box-shadow:0 0 0 1px rgba(34,224,214,.35),0 8px 20px rgba(108,60,233,.45);
}
.rail__brand-mark::after{
  content:"";position:absolute;top:9px;right:9px;width:7px;height:7px;
  border-radius:2px;background:var(--ink);
}
.rail__brand-text{display:flex;flex-direction:column;line-height:1.2}
.rail__brand-name{font-size:16px;font-weight:800;letter-spacing:.04em}
.rail__brand-line{display:none;margin-top:4px;font-size:11px;letter-spacing:.14em;color:var(--stone)}

.rail__status{display:none;align-items:center;gap:8px}
.dot{width:7px;height:7px;border-radius:50%;background:var(--moss);flex:0 0 auto}
.dot--live{background:var(--cyan);box-shadow:0 0 0 4px rgba(34,224,214,.16)}

.rail__toggle{
  display:inline-flex;align-items:center;gap:9px;
  padding:8px 14px 8px 12px;
  border:1px solid rgba(34,224,214,.45);border-radius:999px;
  background:rgba(34,224,214,.08);color:var(--bone);
  font-size:13px;font-weight:700;letter-spacing:.1em;
  transition:background-color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.rail__toggle:hover{background:rgba(34,224,214,.16)}
.rail__toggle-bars{position:relative;width:16px;height:10px}
.rail__toggle-bars::before,.rail__toggle-bars::after{
  content:"";position:absolute;left:0;right:0;height:2px;border-radius:2px;background:var(--cyan);
  transition:transform var(--dur) var(--ease);
}
.rail__toggle-bars::before{top:0}
.rail__toggle-bars::after{bottom:0}
.rail[data-open="true"] .rail__toggle-bars::before{transform:translateY(4px) rotate(45deg)}
.rail[data-open="true"] .rail__toggle-bars::after{transform:translateY(-4px) rotate(-45deg)}

.rail__panel{
  position:absolute;top:var(--top-h);left:0;right:0;
  max-height:0;overflow:hidden;visibility:hidden;
  background:linear-gradient(180deg,#0F1839,#16224F);
  border-bottom:1px solid rgba(34,224,214,.28);
  box-shadow:0 24px 44px rgba(4,7,22,.6);
  transition:max-height .28s var(--ease),visibility .28s;
}
.rail[data-open="true"] .rail__panel{
  max-height:calc(100vh - var(--top-h));
  overflow-y:auto;
  visibility:visible;
}

.rail__nav{padding:10px 16px 0}
.rail__list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:4px}
.rail__list a{
  position:relative;
  display:flex;align-items:baseline;gap:12px;
  padding:11px 12px 11px 16px;
  border-radius:var(--r-sm);
  color:var(--bone);text-decoration:none;
  font-size:15px;letter-spacing:.02em;
  transition:background-color var(--dur) var(--ease),color var(--dur) var(--ease);
}
.rail__list a::before{
  content:"";position:absolute;left:0;top:9px;bottom:9px;width:2px;border-radius:2px;
  background:linear-gradient(180deg,var(--cyan),var(--violet));
  transform:scaleX(0);transform-origin:left center;
  transition:transform .2s var(--ease);
}
.rail__list a:hover{background:rgba(108,60,233,.2)}
.rail__list a:hover::before{transform:scaleX(1)}
.rail__list a[aria-current="page"]{
  background:linear-gradient(90deg,rgba(108,60,233,.34),rgba(108,60,233,.1));
  color:#fff;
  box-shadow:inset 0 0 0 1px rgba(34,224,214,.4);
}
.rail__list a[aria-current="page"]::before{transform:scaleX(1)}
.rail__num{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;
  color:var(--stone);transition:color var(--dur) var(--ease);
}
.rail__list a[aria-current="page"] .rail__num{color:var(--cyan)}
.rail__label{font-weight:700}

.rail__foot{display:flex;flex-direction:column;gap:8px;margin:16px 16px 22px;padding-top:16px;border-top:1px solid var(--line)}

/* ---------- 6. 页脚 ---------- */
.site-footer{
  position:relative;
  padding:56px 0 30px;
  background:linear-gradient(180deg,#0B1233,#111B3E 55%,#0B1233);
  border-top:1px solid var(--line);
  color:var(--bone);
}
.site-footer::before{
  content:"";position:absolute;top:-1px;left:0;right:0;height:1px;
  background:linear-gradient(90deg,transparent,var(--cyan),var(--violet),transparent);
  opacity:.75;
}
.footer__inner{position:relative}
.footer__grid{display:grid;gap:32px;grid-template-columns:minmax(0,1fr)}

.footer__logo{font-size:20px;font-weight:800;letter-spacing:.03em;text-decoration:none;color:var(--bone)}
.footer__logo:hover{color:var(--cyan)}
.footer__tagline{margin-top:10px;font-size:12px;letter-spacing:.18em;color:var(--cyan)}
.footer__note{margin-top:14px;max-width:32em;font-size:13.5px;line-height:1.85;color:var(--stone)}

.footer__title{
  font-family:var(--font-mono);font-size:12px;font-weight:600;
  letter-spacing:.18em;text-transform:uppercase;color:var(--stone);
}
.footer__list{list-style:none;margin:14px 0 0;padding:0;display:flex;flex-direction:column;gap:10px}
.footer__list a{
  display:inline-block;
  font-size:14.5px;color:var(--bone);text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.footer__list a:hover{color:var(--cyan);border-bottom-color:rgba(34,224,214,.5)}

.footer__meta{
  display:flex;flex-wrap:wrap;align-items:center;gap:12px 24px;
  margin-top:44px;padding-top:22px;
  border-top:1px solid var(--line);
  font-size:13.5px;color:var(--stone);
}
.footer__meta-item{display:inline-flex;align-items:baseline;gap:10px}
.footer__meta-key{font-family:var(--font-mono);font-size:11px;letter-spacing:.16em;color:rgba(138,147,163,.85)}

.footer__legal{
  display:flex;flex-wrap:wrap;justify-content:space-between;gap:10px 20px;
  margin-top:20px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;color:var(--stone);
}

/* ---------- 7. 响应式与无障碍 ---------- */
@media (min-width:600px){
  .grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer__grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (min-width:900px){
  .grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
  .grid--4{grid-template-columns:repeat(4,minmax(0,1fr))}
}
@media (min-width:1024px){
  :root{--rail-w:288px}
  body{padding-top:0;padding-left:var(--rail-w)}

  .skip-link{left:calc(var(--rail-w) + 16px)}

  .rail{
    top:0;left:0;bottom:0;right:auto;
    width:var(--rail-w);height:auto;
    flex-direction:column;align-items:stretch;justify-content:flex-start;
    padding:26px 20px 24px;
    background:
      radial-gradient(120% 55% at 100% 0%,rgba(108,60,233,.36),transparent 62%),
      linear-gradient(180deg,#0B1233 0%,#101B40 58%,#16224F 100%);
    border-right:1px solid var(--line);
    border-bottom:0;
  }
  .rail::after{
    content:"";position:absolute;top:12%;bottom:12%;right:-1px;width:1px;
    background:linear-gradient(180deg,transparent,var(--cyan),transparent);
    opacity:.5;
  }
  .rail__top{
    flex-direction:column;align-items:flex-start;gap:0;width:auto;
    padding-bottom:20px;margin-bottom:20px;
    border-bottom:1px solid var(--line);
  }
  .rail__brand-line{display:block}
  .rail__status{
    display:inline-flex;
    margin-top:16px;padding:6px 11px;
    border:1px solid var(--line);border-radius:999px;
    background:rgba(34,224,214,.06);
    font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;color:var(--stone);
  }
  .rail__toggle{display:none}

  .rail__panel{
    position:static;
    display:flex;flex-direction:column;gap:22px;
    flex:1 1 auto;min-height:0;
    max-height:none;overflow:visible;
    visibility:visible;
    background:none;border:0;box-shadow:none;
    transition:none;
  }
  .rail__nav{padding:0}
  .rail__foot{margin:0;padding-top:18px;padding-left:0;padding-right:0}

  .footer__grid{grid-template-columns:1.5fr 1fr 1fr 1fr;gap:28px 32px}
  .band{padding:84px 0}
  .wrap{padding:0 40px}
  .scroll-progress{left:var(--rail-w)}
}
@media (min-width:1280px){
  .rail{padding:32px 24px 28px}
}

@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}
  .card:hover{transform:none}
}