:root{
  --bg:#F6F7F8;--bg-top:#FBFCFC;--bg-bottom:#F1F3F4;--panel:#FFFFFF;--panel-2:#ECEFF1;--panel-soft:#F8FAFA;--sidebar:#F1F4F3;
  --border:#DCE1E5;--border-soft:#E6EAED;--head-bg:rgba(251,252,252,.82);
  --accent:#10B86A;--accent-dark:#077A47;--accent-ink:#062A19;--accent-hover:#1BC876;
  --tray-hi:#7DF2B4;--tray-mid:#12B76A;--tray-edge:#0B8F57;--teal:#0A97A3;--ink-green:#0E2A20;--on-ink:#E4F2EB;--on-ink-muted:#A7C6B7;--data-blue:#2F7CF6;
  --text:#0F1A22;--muted:#5A6773;--faint:#8994A0;--success:#0E9F5B;--warn:#C9800A;--error:#D43F3F;
  --grid:rgba(15,26,34,.04);--sh-emerald:rgba(16,184,106,.14);--sh-emerald-soft:rgba(16,184,106,.10);--sh-deep:rgba(4,52,31,.20);--sh-ink:rgba(15,26,34,.07);
  --hi:rgba(255,255,255,.96);--hi-soft:rgba(255,255,255,.6);--hi-faint:rgba(255,255,255,.24);--clear:rgba(255,255,255,0);--veil:rgba(15,26,34,.35);
  --flag-red:#D52B3C;--flag-blue:#23408C;--flag-white:#FFFFFF;
  --font-display:'Iowan Old Style','Palatino Linotype',Georgia,'Noto Sans SC','PingFang SC','Hiragino Sans','Microsoft YaHei',serif;
  --font-body:'Inter','Noto Sans SC','PingFang SC','Hiragino Sans','Yu Gothic','Apple SD Gothic Neo','Malgun Gothic','Microsoft YaHei',system-ui,sans-serif;
  --font-mono:'JetBrains Mono',ui-monospace,'SFMono-Regular',Menlo,Consolas,monospace;
  --r-btn:2px;--r-xs:3px;--r-sm:4px;--r-md:8px;--r-lg:12px;--r-tray:28px;--r-pill:999px;--r-round:50%;
  --gutter:32px;--wrap:1344px;--grid-size:88px;--head-height:60px;--anchor-offset:84px;--toc-offset:16px;--toc-landing:88px;
  --size-display:64px;--size-h2:48px;--size-h3:24px;--size-body:16px;--size-small:14px;
  --shadow-panel:inset 0 1px 0 var(--hi),0 18px 40px var(--sh-emerald-soft),0 2px 6px var(--sh-ink);
  --ease:ease;--duration:.18s;--reveal-duration:.35s;
}
*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-offset);scroll-behavior:smooth}
body{min-height:100vh;font-family:var(--font-body);font-size:var(--size-body);color:var(--text);line-height:1.6;background-color:var(--bg);background-image:linear-gradient(var(--grid) 1px,var(--clear) 1px),linear-gradient(90deg,var(--grid) 1px,var(--clear) 1px),linear-gradient(180deg,var(--bg-top) 0%,var(--bg) 46%,var(--bg-bottom) 100%);background-size:var(--grid-size) var(--grid-size),var(--grid-size) var(--grid-size),100% 100%;background-position:center top,center top,0 0;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
ul{list-style:none}
img{max-width:100%;height:auto;display:block}
svg{flex-shrink:0}
button,a,summary{-webkit-tap-highlight-color:var(--sh-emerald-soft)}
:focus-visible{outline:2px solid var(--text);outline-offset:3px}
[hidden]{display:none!important}
h1,h2,h3{font-weight:400;text-wrap:balance;overflow-wrap:break-word}
h1{font-family:var(--font-display);font-size:clamp(52px,5vw,var(--size-display));line-height:1.1;letter-spacing:-.02em}
h2{font-family:var(--font-display);font-size:var(--size-h2);line-height:1.2;letter-spacing:-.01em}
h3{font-size:var(--size-h3);line-height:1.35}
p{overflow-wrap:break-word}
code{font-family:var(--font-mono);overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:20px;background:var(--panel-2);border:1px solid var(--border);border-radius:var(--r-md)}
pre code{white-space:pre;overflow-wrap:normal}
.no-break{white-space:nowrap}
.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.skip{position:absolute;left:16px;top:-80px;z-index:100;padding:8px 14px;background:var(--text);color:var(--panel);border-radius:var(--r-sm);font-size:var(--size-small)}
.skip:focus{top:8px}
.wrap{width:100%;max-width:var(--wrap);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-top:72px;padding-bottom:72px}
.section-head{display:flex;justify-content:space-between;align-items:baseline;gap:24px;margin-bottom:32px}
.section-head a{flex-shrink:0;min-height:24px}
.stack>*+*{margin-top:16px}
.muted{color:var(--muted)}
.mono{font-family:var(--font-mono)}
.panel,.card{background:var(--panel);border:1px solid var(--border-soft);border-radius:var(--r-md);box-shadow:var(--shadow-panel);padding:24px}
.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.grid>*,.section-head>*,.panel,.card,main,article,section{min-width:0}
.prose{max-width:860px}
.prose p,.prose ul,.prose ol,.prose pre,.prose table{margin-block:20px}
.prose h2{font-size:36px;margin-top:48px;margin-bottom:20px}
.prose h3{margin-top:32px;margin-bottom:16px}
.prose ul{list-style:disc;padding-left:24px}
.prose ol{padding-left:24px}
.prose a{text-decoration:underline;text-underline-offset:4px}
.prose li+li{margin-top:8px}
.btn{display:inline-flex;align-items:center;justify-content:center;height:48px;min-width:172px;padding:0 32px;font-size:16px;font-weight:600;letter-spacing:.02em;border:1px solid var(--clear);border-radius:var(--r-btn);transition:background-color var(--duration) var(--ease),color var(--duration) var(--ease),box-shadow var(--duration) var(--ease);flex-shrink:0;white-space:nowrap}
.btn-primary{background:var(--accent);border-color:var(--accent);color:var(--accent-ink);box-shadow:inset 0 1px 0 var(--hi-faint),0 10px 24px var(--sh-emerald)}
.btn-primary:hover,.btn-primary.is-hover{background:var(--accent-hover)}
.btn-ghost,.btn-secondary{background:var(--clear);border-color:var(--text);color:var(--text)}
.btn-ghost:hover,.btn-secondary:hover,.btn-ghost.is-hover{background:var(--panel)}
.btn:active,.btn.is-active{box-shadow:inset 0 2px 6px var(--sh-deep)}
.btn:disabled,.btn[aria-disabled="true"]{background:var(--panel-2);border-color:var(--border);color:var(--muted);box-shadow:none;cursor:not-allowed}
.btn-small{min-width:0;height:40px;padding-inline:18px;font-size:14px}
.text-link{display:inline-flex;align-items:center;min-height:24px;gap:8px}
.text-link:hover{text-decoration:underline;text-underline-offset:4px}
.cta-row{margin-top:20px;display:flex;justify-content:center;gap:16px;flex-wrap:wrap}
.announce{background:var(--ink-green);color:var(--on-ink);font-size:13px}
.announce-in{height:36px;display:flex;align-items:center;justify-content:center;gap:14px}
.announce-tag{font-family:var(--font-mono);font-size:11px;font-weight:600;letter-spacing:.06em;line-height:18px;padding:2px 11px;border-radius:var(--r-pill);background:var(--accent);color:var(--accent-ink);flex-shrink:0}
.announce-text{color:var(--on-ink-muted)}
.announce-link{color:var(--on-ink);font-weight:600;display:inline-flex;align-items:center;min-height:24px}
.announce-link:hover{text-decoration:underline;text-underline-offset:3px}
#site-header{position:relative;z-index:40}
.site-head{position:relative;z-index:43;background:var(--head-bg);border-bottom:1px solid var(--border-soft);backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px)}
.head-in{height:var(--head-height);display:flex;align-items:center;gap:40px;flex-wrap:nowrap}
.brand{display:flex;align-items:center;gap:10px;flex:none;min-height:30px}
.brand-mark{width:30px;height:30px;border-radius:var(--r-md);flex:none;box-shadow:0 4px 12px var(--sh-emerald)}
.brand-en{font-family:var(--font-display);font-size:21px;line-height:1;letter-spacing:-.01em;color:var(--text)}
.brand-zh{font-size:13px;line-height:16px;color:var(--muted);font-weight:400;padding-left:10px;border-left:1px solid var(--border)}
.main-nav{flex:1;min-width:0}
.nav-list{display:flex;align-items:center;list-style:none;margin:0;padding:0;gap:2px}
.nav-list>li{flex-shrink:0}
.nav-link,.more-btn{position:relative;display:inline-flex;align-items:center;gap:6px;height:36px;padding:0 14px;font-size:15px;color:var(--text);border-radius:var(--r-sm);background:none;border:0;cursor:pointer;white-space:nowrap}
.nav-link:hover,.more-btn:hover{background:var(--panel-2)}
.nav-link[aria-current="page"],.more-link[aria-current="page"],.more-btn.is-current{font-weight:600}
.nav-link[aria-current="page"]::after{content:"";position:absolute;left:14px;right:14px;bottom:4px;height:1px;background:var(--text)}
.more-caret{font-size:11px;color:var(--muted)}
.more{position:relative}
.more-panel{position:absolute;z-index:46;top:calc(100% + 8px);left:-8px;width:400px;display:grid;grid-template-columns:1fr 1fr;gap:4px 20px;padding:16px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-lg);box-shadow:var(--shadow-panel)}
.more-group-h{font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--muted);padding:0 8px 6px}
.more-link{display:block;padding:8px;border-radius:var(--r-sm);min-height:44px}
.more-link:hover{background:var(--panel-soft)}
.more-link b{display:block;font-size:14px;font-weight:600;line-height:20px}
.more-link span{display:block;font-size:12px;line-height:18px;color:var(--muted)}
.head-actions{display:flex;align-items:center;gap:8px;flex-shrink:0;margin-left:auto}
.language{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;height:36px;width:auto;min-width:44px;padding:0 10px;border:0;background:none;font-size:14px;color:var(--muted);cursor:pointer;border-radius:var(--r-sm);white-space:nowrap}
.lang span{white-space:nowrap}
.lang:hover{background:var(--panel-2);color:var(--text)}
.lang svg{width:16px;height:16px}
.lang-panel{position:absolute;right:0;top:calc(100% + 8px);width:180px;z-index:48;padding:8px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--shadow-panel)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-sm)}
.lang-panel a:hover,.lang-panel a[aria-current]{background:var(--panel-2)}
.login{display:inline-flex;align-items:center;justify-content:center;height:36px;padding:0 20px;font-size:14px;font-weight:600;background:var(--text);color:var(--panel);border-radius:var(--r-btn);white-space:nowrap}
.login:hover{background:var(--ink-green)}
.menu-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;background:none;border:1px solid var(--border);border-radius:var(--r-sm)}
.menu-line{display:block;width:20px;height:2px;background:currentColor}
.mobile-drawer{position:fixed;top:var(--head-height);right:0;left:0;height:calc(100dvh - var(--head-height));max-height:calc(100dvh - var(--head-height));overflow-y:auto;overscroll-behavior:contain;z-index:42;background:var(--panel);padding:20px var(--gutter)}
.mobile-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px;border-bottom:1px solid var(--border-soft)}
.mobile-drawer a[aria-current="page"]{font-weight:600;background:var(--panel-2)}
.drawer-label{font-family:var(--font-mono);font-size:12px;color:var(--muted);padding:20px 12px 8px}
.nav-veil{position:fixed;top:var(--head-height);inset-inline:0;bottom:0;z-index:41;background:var(--veil);border:0}
html.nav-open{overflow:hidden}
.site-foot{border-top:1px solid var(--border);background:var(--panel-soft);padding-top:48px;padding-bottom:24px}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr 1fr;gap:32px}
.footer-brand p{color:var(--muted);font-size:14px;margin-top:16px;max-width:300px}
.footer-title{font-family:var(--font-mono);font-size:13px;font-weight:600;margin-bottom:12px}
.footer-links a{display:inline-flex;align-items:center;min-height:30px;font-size:14px;color:var(--muted)}
.footer-links a:hover{color:var(--text);text-decoration:underline;text-underline-offset:3px}
.footer-bottom{margin-top:32px;padding-top:20px;border-top:1px solid var(--border);display:flex;justify-content:space-between;gap:16px;flex-wrap:wrap;font-size:13px;color:var(--muted)}
.footer-legal{display:flex;gap:20px;flex-wrap:wrap}
.footer-legal a{display:inline-flex;align-items:center;min-height:24px}
.reveal{transition:opacity var(--reveal-duration) ease,transform var(--reveal-duration) ease}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:static;display:block;min-height:80px;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:32px}
#server-status+*{margin-top:32px}
.decor-region{position:relative;overflow-x:clip;max-width:100%}
.decor-layer{position:absolute;inset:10%;pointer-events:none;background:radial-gradient(ellipse,var(--sh-emerald-soft),var(--clear) 70%);max-width:100%}
@media(max-width:1100px){.head-in{gap:20px}.nav-link,.more-btn{padding-inline:10px}}
@media(max-width:980px){
  .main-nav{display:none}.menu-toggle{display:flex}.head-actions{margin-left:auto}.head-in{gap:12px}
  .announce{display:none}.footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(min-width:981px){.mobile-drawer,.nav-veil{display:none!important}}
@media(max-width:768px){
  h1{font-size:40px;line-height:1.15}h2{font-size:34px}.section{padding-top:48px;padding-bottom:48px}
  .grid{grid-template-columns:1fr}.section-head{flex-wrap:wrap;gap:16px}.head-actions{gap:4px}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}.wrap{padding-inline:var(--gutter)}
  .tilt,[data-tilt]{transform:none}
  .decor-layer{max-width:100%}.footer-grid{grid-template-columns:1fr}
  .brand{gap:7px}.brand-en{font-size:19px}.brand-mark{width:26px;height:26px}
  .head-in{gap:6px}.login{padding-inline:12px;font-size:13px}
  .lang{padding-inline:5px;font-size:12px;gap:3px}.lang svg{display:none}
  .menu-toggle{min-width:44px}.panel,.card{padding:20px}.prose h2{font-size:30px}
  .cta-row{width:100%;gap:12px}.cta-row .btn{min-width:0;padding-inline:20px;flex:1 1 130px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition:none!important;animation:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}