:root{
  --bg:#E8ECF5;--bg-panel:#F7F8FC;--bg-panel-2:#DBE1EE;--border:#CBD2E2;--line:#E2E6EF;
  --accent:#4B1A2E;--accent-dark:#2E0F1C;--accent-2:#7A3350;--accent-tint:#ECDDE4;
  --text:#1A1D2B;--text-muted:#5A6178;--success:#2F8A63;--success-tint:#DCEFE5;--warn:#B7791F;--error:#B43A3A;--white:#FFFFFF;
  --hero-top:#EEF1F8;--hero-bottom:#E2E7F2;--sky:#9FB0CC;--lavender:#C9C3E0;--apricot:#EBD3C4;
  --lav-tint:#ECE9F5;--lav-edge:rgba(122,51,80,.10);--lav-wash:rgba(201,195,224,.38);
  --mount-back:#B2B1D2;--mount-front:#D8C3C4;--ridge-wash:rgba(178,177,210,.42);
  --flag-red:#C8333B;--flag-blue:#27407E;--flag-white:#FFFFFF;--flag-edge:rgba(26,29,43,.16);
  --shadow-tint:rgba(75,26,46,.10);--shadow-tint-soft:rgba(75,26,46,.06);--shadow-tint-strong:rgba(75,26,46,.24);
  --inset-shade:rgba(26,29,43,.07);--seg-edge:rgba(26,29,43,.05);
  --glass:rgba(255,255,255,.80);--glass-hi:rgba(255,255,255,.34);--glow-white:rgba(255,255,255,.58);
  --win-edge:rgba(255,255,255,.72);--btn-shine:rgba(255,255,255,.18);--clear:transparent;
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Apple SD Gothic Neo","Microsoft YaHei","Malgun Gothic",sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Apple SD Gothic Neo","Microsoft YaHei","Malgun Gothic",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SF Mono",Menlo,Consolas,monospace;
  --r-xs:4px;--r-sm:6px;--r-md:8px;--r-lg:10px;--r-xl:12px;--r-pill:999px;--r-circle:50%;
  --gutter:48px;--wrap-width:1440px;--header-height:64px;--anchor-gap:80px;--toc-offset:0px;--toc-landing:80px;
  --body-size:17px;--body-leading:1.7;--display-size:clamp(52px,4.45vw,64px);--h2-size:clamp(28px,3vw,40px);
  --soft-shadow:0 24px 48px var(--shadow-tint),0 2px 6px var(--shadow-tint-soft);
  --card-shadow:0 12px 48px var(--shadow-tint);
  --ease-out:cubic-bezier(.2,.7,.2,1);--reveal-duration:600ms;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-gap);scroll-behavior:smooth}
html.nav-open{overflow:hidden}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font-body);font-size:var(--body-size);line-height:var(--body-leading);-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit}
button{cursor:pointer;color:inherit}
button:disabled{cursor:not-allowed}
button{border:0}
img{display:block;max-width:100%;height:auto}
svg{flex-shrink:0}
button svg,a svg{flex-shrink:0}
h1,h2,h3,h4,p,blockquote,figure{margin:0}
h1,h2,h3{font-family:var(--font-display);text-wrap:balance;overflow-wrap:break-word}
h1{font-size:var(--display-size);line-height:1.12;font-weight:800;letter-spacing:-.02em}
h2{font-size:var(--h2-size);line-height:1.25;letter-spacing:-.02em;font-weight:750}
h3{font-size:24px;line-height:1.35;font-weight:700}
ul,ol{padding-left:1.5em}
.no-break{white-space:nowrap}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
[hidden]{display:none!important}
.wrap{max-width:var(--wrap-width);margin-inline:auto;padding-inline:var(--gutter);min-width:0;width:100%}
.section{padding-top:72px;padding-bottom:72px}
.section__head{margin-bottom:32px}
.section__head p{margin-top:16px;max-width:760px;color:var(--text-muted)}
.reading-wrap{max-width:960px;margin-inline:auto;padding-inline:var(--gutter);min-width:0}
.prose{min-width:0;overflow-wrap:break-word}
.prose p,.prose ul,.prose ol,.prose blockquote{margin-block:20px}
.prose h2{margin-top:48px;margin-bottom:20px}
.prose h3{margin-top:32px;margin-bottom:16px}
.prose a{ text-decoration:underline;text-underline-offset:4px}
code{font-family:var(--font-mono);overflow-wrap:anywhere;font-size:.9em}
pre{max-width:100%;min-width:0;overflow-x:auto;padding:24px;background:var(--bg-panel-2);border:1px solid var(--border);border-radius:var(--r-md)}
pre code{overflow-wrap:normal;white-space:pre;font-size:14px}
.muted{color:var(--text-muted)}
.mono{font-family:var(--font-mono)}
.card,.panel{min-width:0;padding:24px;border:1px solid var(--border);border-radius:var(--r-lg);background:var(--bg-panel);box-shadow:var(--card-shadow)}
.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.grid>*{min-width:0}
.decorated{position:relative;overflow-x:clip}
#server-status{position:relative;display:block;min-width:0;max-width:100%;min-height:120px;overflow:hidden;margin-block:24px}
#server-status+*{margin-top:32px}
.reveal{transition:opacity var(--reveal-duration) var(--ease-out),transform var(--reveal-duration) var(--ease-out)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
.stat-number{display:inline-block;min-width:3ch;font-variant-numeric:tabular-nums;font-family:var(--font-mono);text-align:right}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:48px;padding:0 30px;border-radius:var(--r-pill);font-size:16px;font-weight:600;line-height:1;white-space:nowrap;flex-shrink:0;max-width:100%;transition:background-color .2s,border-color .2s;min-width:24px}
.btn svg{width:16px;height:16px}
.btn--primary,.btn-primary{padding-inline:36px;color:var(--white);background:linear-gradient(135deg,var(--accent) 0%,var(--accent) 38%,var(--accent-2) 100%);box-shadow:0 10px 24px var(--shadow-tint-strong),inset 0 1px 0 var(--btn-shine)}
.btn--primary:hover,.btn-primary:hover,.btn--primary.is-hover{background:linear-gradient(135deg,var(--accent-dark) 0%,var(--accent) 45%,var(--accent-2) 100%)}
.btn--ghost,.btn-secondary{background:var(--white);color:var(--text);border:1px solid var(--border);box-shadow:0 1px 2px var(--shadow-tint-soft)}
.btn--ghost:hover,.btn-secondary:hover{border-color:var(--text-muted)}
.btn:disabled,.btn[aria-disabled="true"]{background:var(--bg-panel-2);color:var(--text-muted);box-shadow:none}
.btn--small{height:36px;padding-inline:20px;font-size:14px}
.cta-row{margin-top:24px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap}
.topbar{height:var(--header-height);position:relative;z-index:30}
.topbar__inner{height:100%;display:flex;align-items:center;gap:32px;position:relative}
.brand{display:flex;align-items:center;gap:10px;flex:0 0 auto;min-height:28px}
.brand img{width:28px;height:28px;flex:none}
.brand__en{font-family:var(--font-display);font-weight:800;font-size:19px;letter-spacing:-.01em;line-height:1}
.brand__zh{font-size:13px;font-weight:500;color:var(--text-muted);line-height:1;padding-left:10px;border-left:1px solid var(--border)}
.tabs{flex:1;display:flex;justify-content:center;min-width:0}
.tabs ul{display:flex;align-items:center;list-style:none;margin:0;padding:0;gap:4px}
.tabs a{position:relative;display:block;height:64px;line-height:64px;padding-inline:12px;font-size:14.5px;font-weight:500;color:var(--text-muted);white-space:nowrap}
.tabs a:hover{color:var(--text)}
.tabs a[aria-current="page"]{color:var(--text);font-weight:600}
.tabs a[aria-current="page"]::after{content:"";position:absolute;left:12px;right:12px;bottom:12px;height:2px;border-radius:var(--r-xs);background:var(--text)}
.topbar__end{display:flex;align-items:center;gap:12px;flex:0 0 auto;margin-left:auto}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:36px;width:auto;padding-inline:10px;border-radius:var(--r-md);font-size:14px;color:var(--text-muted);line-height:1;background:var(--clear);white-space:nowrap}
.lang span{white-space:nowrap}
.lang svg{width:16px;height:16px}
.language-control{position:relative}
.language-menu{position:absolute;right:0;top:calc(100% + 8px);min-width:180px;padding:8px;background:var(--white);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--soft-shadow);z-index:40}
.language-menu a{display:flex;align-items:center;min-height:44px;padding:8px 12px;font-size:14px;border-radius:var(--r-sm)}
.language-menu a:hover,.language-menu a[aria-current="true"]{background:var(--bg-panel-2)}
.login{display:inline-flex;align-items:center;justify-content:center;height:36px;padding-inline:20px;border-radius:var(--r-pill);background:var(--white);border:1px solid var(--border);font-size:14px;font-weight:600;line-height:1;box-shadow:0 1px 2px var(--shadow-tint-soft);white-space:nowrap}
.login:hover{border-color:var(--text-muted)}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;background:var(--clear);border-radius:var(--r-md)}
.menu-toggle svg{width:22px;height:22px}
.mobile-drawer{display:none}
.site-footer{background:var(--bg-panel-2);border-top:1px solid var(--border);padding-top:56px;padding-bottom:24px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr 1fr;gap:40px}
.footer-grid>*{min-width:0}
.footer-brand p{margin-top:16px;max-width:320px;color:var(--text-muted);font-size:14px}
.footer-title{font-size:15px;font-weight:700;margin-bottom:12px}
.footer-list{list-style:none;margin:0;padding:0}
.footer-list a{display:inline-flex;align-items:center;min-height:32px;font-size:14px;color:var(--text-muted);padding-block:4px;overflow-wrap:anywhere}
.footer-list a:hover{color:var(--text);text-decoration:underline;text-underline-offset:4px}
.footer-bottom{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px;margin-top:40px;padding-top:20px;border-top:1px solid var(--border);font-size:13px;color:var(--text-muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:16px}
.footer-legal a{display:inline-flex;align-items:center;min-height:24px}
@media(max-width:1180px){
  .tabs a{padding-inline:9px;font-size:14px}
  .tabs a[aria-current="page"]::after{left:9px;right:9px}
  .brand__zh{display:none}
  .topbar__inner{gap:20px}
}
@media(max-width:1024px){
  .topbar__inner{gap:12px}
  .topbar .tabs{display:none}
  .topbar__end{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .mobile-drawer:not([hidden]){display:block;position:absolute;left:var(--gutter);right:var(--gutter);top:64px;background:var(--bg-panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--soft-shadow);padding:12px;max-height:calc(100dvh - 80px);overflow-y:auto;overscroll-behavior:contain;z-index:35}
  .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 16px;border-radius:var(--r-sm);font-size:15px}
  .mobile-drawer a[aria-current="page"],.mobile-drawer a:hover{background:var(--bg-panel-2);font-weight:600}
  .drawer-languages{border-top:1px solid var(--border);padding-top:8px;margin-top:8px}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:768px){
  :root{--gutter:24px;--display-size:40px}
  .grid{grid-template-columns:1fr}
  .section{padding-top:48px;padding-bottom:48px}
  .topbar__end{gap:8px}
}
@media(max-width:640px){
  :root{--gutter:20px;--display-size:36px}
  .no-break{white-space:normal}
  .brand__en{font-size:17px}
  .brand{gap:6px}
  .brand img{width:24px;height:24px}
  .lang{padding-inline:4px}
  .login{padding-inline:14px}
  .topbar__inner{gap:8px}
  .topbar__end{gap:4px;margin-left:auto}
  .footer-grid{grid-template-columns:1fr;gap:24px}
  .tilt{transform:none}
  .decorated{max-width:100%;overflow-x:clip}
  .cta-row{flex-direction:column;align-items:stretch;width:100%;max-width:320px}
  .card,.panel{padding:20px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none;transition:none}
}