:root{
  --bg:#E3E9F6;--bg-panel:#F5F8FD;--bg-panel2:#D6DFF0;--border:#C3CFE6;
  --accent:#0B84FF;--accent-dark:#0059C8;--text:#0D1630;--text-muted:#4E5B78;
  --success:#13A37A;--warn:#C77D08;--error:#D6334A;--white:#FFFFFF;
  --hero-top:#EDF2FB;--hero-bottom:#DCE4F3;--win-top:#F7FAFF;--win-bottom:#E6EEFC;--accent-tint:#E3EFFF;
  --accent-rgb:11 132 255;--accent-dark-rgb:0 89 200;--ice-rgb:156 203 255;--ink-rgb:13 22 48;
  --white-rgb:255 255 255;--border-rgb:195 207 230;--panel-rgb:245 248 253;--panel2-rgb:214 223 240;
  --flag-red:#D9283E;--flag-white:#FFFFFF;--flag-blue:#253A7A;--flag-navy:#13246B;--flag-green:#118A4E;
  --font-display:"Inter","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --radius-xs:6px;--radius-sm:8px;--radius:12px;--radius-lg:16px;--radius-pill:999px;--radius-dot:50%;
  --size-tiny:11px;--size-caption:12px;--size-small:13px;--size-nav:14.5px;--size-label:14px;
  --size-button:15px;--size-body:16px;--size-lede:17px;--size-brand:18px;--size-subtitle:22px;
  --size-h1:clamp(52px,5vw,64px);--size-h2:36px;--size-h3:22px;
  --weight-normal:400;--weight-medium:500;--weight-semibold:650;--weight-bold:700;--weight-heavy:800;--weight-display:900;
  --gutter:32px;--content-width:1240px;--reading-width:780px;--head-height:64px;--anchor-offset:80px;--toc-offset:144px;
  --shadow-panel:inset 0 1px 0 var(--white),0 20px 48px -24px rgb(var(--accent-rgb) / 12%);
  --shadow-float:inset 0 1px 0 var(--white),0 2px 6px rgb(var(--accent-dark-rgb) / 8%),0 16px 32px -12px rgb(var(--accent-rgb) / 42%);
  --ease-short:150ms ease;--ease-reveal:600ms ease;
}
*,*::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:var(--size-body);line-height:1.5;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit;text-underline-offset:3px}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
button,a,summary{-webkit-tap-highlight-color:rgb(var(--accent-rgb) / 12%)}
button:focus-visible,a:focus-visible,summary:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
button:disabled{cursor:not-allowed}
img{max-width:100%;height:auto}
svg{flex-shrink:0}
[hidden]{display:none!important}
h1,h2,h3{font-family:var(--font-display);text-wrap:balance}
h1{font-size:var(--size-h1);font-weight:var(--weight-display);line-height:1.1;letter-spacing:-0.02em;margin:0}
h2{font-size:var(--size-h2);line-height:1.2;font-weight:var(--weight-heavy);letter-spacing:-0.02em;margin:0 0 20px}
h3{font-size:var(--size-h3);line-height:1.35;font-weight:var(--weight-bold);margin:0 0 12px}
p{margin:0 0 20px}
code{font-family:var(--font-mono);overflow-wrap:anywhere;font-size:var(--size-label)}
pre{max-width:100%;overflow-x:auto;padding:20px;border:1px solid var(--border);border-radius:var(--radius);background:var(--bg-panel2)}
pre code{overflow-wrap:normal;white-space:pre}
table{border-collapse:collapse}
th,td{word-break:keep-all}
.wrap{width:100%;max-width:calc(var(--content-width) + 64px);margin-inline:auto;padding-inline:var(--gutter)}
.reading-wrap{width:100%;max-width:calc(var(--reading-width) + 64px);margin-inline:auto;padding-inline:var(--gutter)}
.sec{padding-top:72px;padding-bottom:80px}
.section-head{margin-bottom:32px}
.section-head p{max-width:640px;color:var(--text-muted)}
.prose{min-width:0;line-height:1.85;overflow-wrap:anywhere}
.prose h2{margin-top:48px}
.prose h3{margin-top:28px}
.prose li{margin-bottom:8px}
.prose a{color:var(--accent-dark)}
.prose section{min-width:0}
.no-break{white-space:nowrap}
.muted{color:var(--text-muted)}
.mono{font-family:var(--font-mono)}
.svg-defs{position:absolute;width:0;height:0;overflow:hidden}
.panel,.card{min-width:0;padding:24px;border:1px solid var(--border);border-radius:var(--radius-lg);background:var(--bg-panel);box-shadow:var(--shadow-panel)}
.card-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.card-grid>*{min-width:0}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;padding:0 22px;border:1px solid transparent;border-radius:var(--radius-pill);font-size:var(--size-button);font-weight:var(--weight-semibold);text-decoration:none;white-space:nowrap;flex-shrink:0;transition:transform var(--ease-short),box-shadow var(--ease-short)}
.btn-ink,.btn-primary{background:var(--text);color:var(--white);box-shadow:inset 0 1px 0 rgb(var(--white-rgb) / 18%),0 12px 24px -12px rgb(var(--ink-rgb) / 60%)}
.btn-ink:hover,.btn-primary:hover{transform:translateY(-1px);box-shadow:inset 0 1px 0 rgb(var(--white-rgb) / 18%),0 16px 28px -12px rgb(var(--ink-rgb) / 65%)}
.btn-ghost,.btn-secondary{background:var(--white);color:var(--text);border-color:var(--border);box-shadow:inset 0 1px 0 var(--white),0 8px 18px -12px rgb(var(--accent-rgb) / 45%)}
.btn-ghost:hover,.btn-secondary:hover{border-color:rgb(var(--accent-rgb) / 55%)}
.btn:active{transform:translateY(0)}
.btn:disabled,.btn[aria-disabled="true"]{background:var(--bg-panel2);color:var(--text-muted);box-shadow:none}
.btn[aria-disabled="true"]{pointer-events:none}
.btn-small{min-height:36px;font-size:var(--size-label);padding-inline:16px}
.btn-focus-sample{outline:2px solid var(--accent);outline-offset:3px}
.site-head,#site-header{position:relative;z-index:50}
.site-head{border-bottom:1px solid rgb(var(--border-rgb) / 55%)}
.head-row{display:flex;align-items:center;height:var(--head-height);gap:44px;position:relative}
.brand{display:inline-flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);flex:none;min-height:36px}
.brand-mark{display:block;width:28px;height:28px}
.brand-en{font-family:var(--font-display);font-weight:var(--weight-heavy);font-size:var(--size-brand);letter-spacing:-0.02em}
.brand-zh{font-size:var(--size-label);font-weight:var(--weight-medium);color:var(--text-muted);padding-left:10px;border-left:1px solid var(--border)}
.main-nav ul{display:flex;align-items:center;gap:28px;list-style:none;margin:0;padding:0}
.main-nav a{display:inline-flex;align-items:center;min-height:28px;font-size:var(--size-nav);font-weight:var(--weight-medium);color:var(--text-muted);text-decoration:none;white-space:nowrap;transition:color var(--ease-short)}
.main-nav a:hover,.main-nav a[aria-current="page"]{color:var(--text)}
.main-nav a[aria-current="page"]{font-weight:var(--weight-bold)}
.head-tools{margin-left:auto;display:flex;align-items:center;gap:20px;flex:none}
.lang-control{position:relative}
.lang-button{display:inline-flex;align-items:center;justify-content:center;min-width:44px;min-height:36px;width:auto;gap:6px;padding:0;border:0;background:transparent;font-size:var(--size-label);color:var(--text-muted);white-space:nowrap}
.lang-menu{position:absolute;right:0;top:calc(100% + 8px);width:180px;padding:8px;border:1px solid var(--border);border-radius:var(--radius);background:var(--bg-panel);box-shadow:var(--shadow-float)}
.lang-menu a{display:flex;align-items:center;min-height:40px;padding:8px 12px;text-decoration:none;font-size:var(--size-label);border-radius:var(--radius-xs)}
.lang-menu a:hover,.lang-menu a[aria-current="true"]{background:var(--accent-tint);color:var(--accent-dark)}
.btn-login{display:inline-flex;align-items:center;justify-content:center;height:36px;padding:0 18px;border-radius:var(--radius-pill);background:var(--white);border:1px solid var(--border);font-size:var(--size-label);font-weight:var(--weight-semibold);color:var(--text);text-decoration:none;white-space:nowrap;box-shadow:inset 0 1px 0 var(--white),0 6px 14px -8px rgb(var(--accent-rgb) / 45%)}
.btn-login:hover{border-color:rgb(var(--accent-rgb) / 55%)}
.nav-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;padding:0;border:0;background:transparent;font-size:var(--size-label);font-weight:var(--weight-semibold)}
.mobile-drawer{display:none}
html.nav-open{overflow:hidden}
.site-footer{border-top:1px solid var(--border);background:var(--bg-panel2);padding-top:48px;padding-bottom:32px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:36px}
.footer-grid>*{min-width:0}
.footer-brand p{max-width:320px;margin-top:16px;font-size:var(--size-label);color:var(--text-muted)}
.footer-heading{font-size:var(--size-label);font-weight:var(--weight-bold);margin:0 0 12px}
.footer-list{list-style:none;margin:0;padding:0;display:grid;gap:4px}
.footer-list a{display:inline-flex;align-items:center;min-height:28px;font-size:var(--size-label);color:var(--text-muted);text-decoration:none}
.footer-list a:hover{color:var(--accent-dark)}
.footer-bottom{display:flex;flex-wrap:wrap;gap:16px 24px;align-items:center;margin-top:32px;padding-top:20px;border-top:1px solid var(--border);font-size:var(--size-small);color:var(--text-muted)}
.footer-bottom p{margin:0;margin-right:auto}
.footer-bottom a{display:inline-flex;align-items:center;min-height:28px}
.reveal{transition:opacity var(--ease-reveal),transform var(--ease-reveal)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:relative;display:block;min-height:72px;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:24px}
#server-status+*{margin-top:24px}
.decorated-section{position:relative;overflow-x:clip;max-width:100%}
.help-section{display:grid;grid-template-columns:minmax(0,1fr);gap:24px}
@media(max-width:1180px){
  .head-row{gap:24px}
  .main-nav ul{gap:18px}
  .head-tools{gap:12px}
}
@media(max-width:960px){
  .main-nav{display:none}
  .nav-toggle{display:inline-flex}
  .head-tools{margin-left:auto}
  .mobile-drawer:not([hidden]){display:block;position:absolute;left:0;right:0;top:var(--head-height);z-index:60;background:var(--bg-panel);border-bottom:1px solid var(--border);padding:16px var(--gutter);max-height:calc(100dvh - var(--head-height));overflow-y:auto;overscroll-behavior:contain;box-shadow:var(--shadow-panel)}
  .mobile-drawer ul{list-style:none;margin:0;padding:0}
  .mobile-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:10px 12px;text-decoration:none;border-radius:var(--radius-xs)}
  .mobile-drawer a[aria-current],.mobile-drawer a:hover{background:var(--accent-tint);color:var(--accent-dark)}
  .drawer-languages{border-top:1px solid var(--border);margin-top:12px;padding-top:12px}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:768px){
  h1{font-size:clamp(28px,7.8vw,40px)}
  h2{font-size:28px}
  .card-grid{grid-template-columns:1fr}
  .sec{padding-top:48px;padding-bottom:48px}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .wrap,.reading-wrap{padding-inline:var(--gutter)}
  .head-row{gap:8px}
  .head-tools{margin-left:auto;gap:8px}
  .head-tools>.lang-control{display:none}
  .brand{gap:8px}
  .brand-en{font-size:var(--size-body)}
  .brand-mark{width:25px;height:25px}
  .btn-login{padding-inline:14px}
  .tilt,.float-note{transform:none}
  .decorated-section{max-width:100%;overflow-x:clip}
  .footer-grid{gap:28px 20px}
  .footer-brand{grid-column:1/-1}
  .panel,.card{padding:20px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition-duration:0s!important;animation-duration:0s!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}