:root{
  --bg:#E7EBF4;--bg-top:#EEF1F8;--bg-bottom:#E3E8F2;--panel:#F7F9FD;--panel-2:#D9DFEC;--border:#C9D1E2;
  --accent:#6A3FD1;--accent-dark:#4A26A8;--rain:#3C7BE6;--text:#161B2E;--muted:#55607A;--success:#1F8A5B;--warn:#B7791F;--error:#C2344D;--white:#FFFFFF;--clear:transparent;
  --accent-a05:rgba(106,63,209,.05);--rain-a05:rgba(60,123,230,.05);--accent-a10:rgba(106,63,209,.10);--accent-a12:rgba(106,63,209,.12);--accent-a14:rgba(106,63,209,.14);--accent-a24:rgba(106,63,209,.24);
  --accent-glow:#CDBDF6;--accent-tint:#B49DEB;--rain-tint:#9DBBF2;
  --deep-a20:rgba(74,38,168,.20);--deep-a35:rgba(74,38,168,.35);--deep-a50:rgba(74,38,168,.50);--deep-a65:rgba(74,38,168,.65);--ink-a12:rgba(22,27,46,.12);--veil:rgba(22,27,46,.35);
  --glass-90:rgba(255,255,255,.90);--glass-70:rgba(255,255,255,.70);--glass-50:rgba(255,255,255,.50);--glass-35:rgba(255,255,255,.35);--glass-22:rgba(255,255,255,.22);--glass-12:rgba(255,255,255,.12);--glass-06:rgba(255,255,255,.06);
  --flag-red:#D52B3A;--flag-blue:#2F3C7E;--flag-white:#FFFFFF;--flag-black:#1B1B1F;--flag-gold:#F2C230;--flag-de-red:#D3232E;
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei","Apple SD Gothic Neo","Malgun Gothic",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --radius:0;--radius-flag:3px;--radius-dot:50%;--gutter:32px;--page-width:1440px;--header-height:64px;--anchor-offset:80px;--toc-offset:144px;--win-h:542px;
  --shadow-panel:0 20px 48px -24px var(--accent-a10);--shadow-raised:0 22px 40px -18px var(--accent-a14);
  --weight-normal:400;--weight-medium:500;--weight-strong:600;--duration:.35s;--ease:cubic-bezier(.2,.7,.3,1);
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-offset);scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font-body);font-size:16px;line-height:1.6;-webkit-font-smoothing:antialiased}
img{display:block;max-width:100%;height:auto}
svg{display:block;flex-shrink:0}
a{color:var(--accent);text-underline-offset:3px}
button,input,select,textarea{font:inherit}
button{cursor:pointer}
button,a{-webkit-tap-highlight-color:var(--accent-a10)}
button{color:inherit}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
[hidden]{display:none!important}
h1,h2,h3{font-family:var(--font-display);font-weight:var(--weight-normal);overflow-wrap:break-word;text-wrap:balance}
h1{font-size:clamp(52px,4.45vw,64px);line-height:1.12;letter-spacing:-.02em}
h2{font-size:32px;line-height:1.3;letter-spacing:-.01em}
h3{font-size:22px;line-height:1.4}
p{margin:0 0 24px}
strong{font-weight:var(--weight-strong)}
code{font-family:var(--font-mono);overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:24px;background:var(--panel-2);border:1px solid var(--border)}
pre code{overflow-wrap:normal;white-space:pre}
blockquote{margin-inline:0}
.wrap{width:100%;max-width:var(--page-width);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-top:64px;padding-bottom:64px}
.section-head{margin-bottom:32px}
.section-head h2{margin:0 0 16px}
.grid{display:grid;gap:24px;grid-template-columns:repeat(3,minmax(0,1fr))}
.grid>*{min-width:0}
main,article,section,aside,nav,figure,div{min-width:0}
.no-break{white-space:nowrap}
.muted{color:var(--muted)}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.skip{position:absolute;left:16px;top:-56px;z-index:60;padding:10px 16px;background:var(--text);color:var(--panel);text-decoration:none;font-size:14px}
.skip:focus{top:12px}
.panel,.card{padding:24px;background:var(--panel);border:1px solid var(--border);border-radius:var(--radius);box-shadow:inset 0 1px 0 var(--white),var(--shadow-panel)}
.panel--inset{background:var(--panel-2)}
.btn{display:inline-flex;align-items:center;justify-content:space-between;gap:32px;min-width:220px;height:56px;padding:0 16px 0 20px;border:1px solid var(--clear);border-radius:var(--radius);font-size:16px;line-height:1;text-decoration:none;flex-shrink:0;white-space:nowrap;font-weight:var(--weight-normal)}
.btn svg{width:20px;height:20px;flex-shrink:0}
.btn--primary{background:var(--accent);color:var(--white);box-shadow:0 12px 24px -14px var(--accent-a24)}
.btn--primary:hover,.btn--primary.is-hover{background:var(--accent-dark)}
.btn--secondary{background:var(--white);color:var(--accent);border-color:var(--accent)}
.btn--secondary:hover,.btn--secondary.is-hover{background:var(--panel)}
.btn:active,.btn.is-active{transform:translateY(1px)}
.btn:disabled,.btn[aria-disabled="true"]{background:var(--panel-2);color:var(--muted);border-color:var(--border);box-shadow:none;cursor:not-allowed}
.btn.is-focus{outline:2px solid var(--accent);outline-offset:2px}
.cta{display:flex;flex-wrap:wrap;gap:16px;margin-top:32px}
.topbar,#site-header{position:sticky;top:0;z-index:40}
.topbar{background:var(--panel);border-bottom:1px solid var(--border)}
#site-header .topbar{position:relative}
.topbar__in{display:flex;align-items:center;height:var(--header-height);gap:32px;flex-wrap:nowrap}
.brand{display:inline-flex;align-items:center;gap:10px;height:32px;padding-right:32px;border-right:1px solid var(--border);text-decoration:none;color:var(--text);flex-shrink:0}
.brand__mark{width:24px;height:24px;flex-shrink:0}
.brand__en{font-family:var(--font-display);font-size:19px;font-weight:var(--weight-strong);letter-spacing:-.01em}
.brand__zh{font-size:14px;color:var(--muted);font-weight:var(--weight-normal)}
.mainnav{flex:1;min-width:0}
.mainnav ul{display:flex;align-items:center;gap:28px;list-style:none;margin:0;padding:0}
.mainnav a{display:block;padding:8px 0;font-size:14px;color:var(--muted);text-decoration:none;white-space:nowrap}
.mainnav a:hover{color:var(--text)}
.mainnav a[aria-current="page"]{color:var(--text);font-weight:var(--weight-strong)}
.topbar__tools{margin-left:auto;display:flex;align-items:center;gap:20px;flex-shrink:0}
.language{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:36px;min-width:44px;width:auto;padding:8px 4px;font:inherit;font-size:14px;color:var(--muted);background:var(--clear);border:0;cursor:pointer;white-space:nowrap}
.lang span{white-space:nowrap}
.lang:hover{color:var(--text)}
.lang-panel{position:absolute;right:0;top:calc(100% + 8px);z-index:55;width:180px;padding:8px;background:var(--panel);border:1px solid var(--border);box-shadow:var(--shadow-raised)}
.lang-panel a{display:flex;align-items:center;width:100%;min-height:44px;padding:8px 12px;color:var(--text);text-decoration:none}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--panel-2)}
.login{display:inline-flex;align-items:center;justify-content:center;height:36px;padding:0 20px;border:1px solid var(--text);border-radius:var(--radius);font-size:14px;color:var(--text);text-decoration:none;white-space:nowrap}
.login:hover{background:var(--text);color:var(--panel)}
.menu-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:5px;min-width:44px;min-height:44px;padding:10px;border:1px solid var(--border);background:var(--panel);color:var(--text)}
.menu-line{display:block;width:20px;height:2px;background:currentColor}
.drawer{display:none;position:fixed;top:var(--header-height);right:0;left:0;height:calc(100dvh - var(--header-height));max-height:calc(100dvh - var(--header-height));overflow-y:auto;overscroll-behavior:contain;z-index:42;background:var(--panel);padding:16px var(--gutter) 32px}
.drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px 8px;border-bottom:1px solid var(--border);color:var(--text);text-decoration:none}
.drawer a[aria-current="page"]{font-weight:var(--weight-strong);border-bottom-color:var(--accent)}
.drawer__languages{margin-top:24px;border-top:1px solid var(--border)}
.nav-veil{display:none;position:fixed;inset:var(--header-height) 0 0;z-index:41;background:var(--veil);border:0}
html.nav-open{overflow:hidden}
.site-footer{padding-top:56px;padding-bottom:24px;background:var(--panel);border-top:1px solid var(--border)}
.footer-grid{display:grid;grid-template-columns:minmax(0,1.4fr) repeat(3,minmax(0,1fr));gap:40px}
.footer-brand .brand{border:0;padding:0}
.footer-brand p{max-width:28em;margin-top:24px;color:var(--muted)}
.footer-heading{margin:0 0 16px;font-size:16px;font-weight:var(--weight-strong)}
.footer-links{list-style:none;padding:0;margin:0}
.footer-links a{display:inline-flex;align-items:center;min-height:32px;color:var(--muted);font-size:14px;text-decoration:none}
.footer-links a:hover{color:var(--accent);text-decoration:underline}
.footer-bottom{display:flex;align-items:center;flex-wrap:wrap;gap:12px 24px;margin-top:40px;padding-top:24px;border-top:1px solid var(--border);font-size:13px;color:var(--muted)}
.footer-bottom p{margin:0}
.footer-bottom a{display:inline-flex;align-items:center;min-height:24px;color:var(--muted)}
.reveal{transition:opacity var(--duration) var(--ease),transform var(--duration) var(--ease)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:relative;display:block;min-height:80px;overflow:hidden;margin-top:24px;margin-bottom:32px;max-width:100%}
#server-status+*{margin-top:32px}
.decoration-region{position:relative;overflow-x:clip}
.prose{max-width:80ch;overflow-wrap:break-word}
.prose h2{margin-top:48px}
.prose h3{margin-top:32px}
.prose li{margin-bottom:8px}
.prose img{height:auto}
@media(max-width:1320px){
  .topbar__in{gap:20px}.brand{padding-right:20px}.mainnav ul{gap:18px}.topbar__tools{gap:12px}
}
@media(max-width:1180px){
  .mainnav{display:none}.menu-toggle{display:flex}.topbar__tools{margin-left:auto}
  .drawer.is-open{display:block}.nav-veil.is-open{display:block}
  .brand{padding-right:0;border-right:0}
}
@media(min-width:1181px){html.nav-open{overflow:auto}}
@media(max-width:768px){
  h1{font-size:36px}h2{font-size:28px}.grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:32px}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .wrap{padding-inline:var(--gutter)}
  .section{padding-top:40px;padding-bottom:40px}
  .topbar__in{gap:8px}.brand{gap:6px}.brand__en{font-size:16px}.brand__mark{width:20px;height:20px}
  .topbar__tools{margin-left:auto;gap:6px}.login{padding-inline:10px;font-size:13px}
  .lang{font-size:12px;gap:3px;padding-inline:2px}
  .grid{grid-template-columns:minmax(0,1fr)}
  .btn{min-width:0;max-width:100%;gap:20px}
  .tilt,.tilt-decoration{transform:none}
  .decoration-region{max-width:100%;overflow-x:clip}
  .footer-grid{grid-template-columns:minmax(0,1fr)}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.01ms!important;transition-duration:.01ms!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}