:root{
  --bg:#FAFAF8;
  --bg-warm:#F2F1ED;
  --bg-panel:#FFFFFF;
  --bg-panel-soft:#FBFBF9;
  --bg-panel-2:#F1F1EE;
  --border:#E4E3DE;
  --border-soft:#EEEDE9;
  --accent:#161410;
  --accent-dark:#050504;
  --text:#1B1A17;
  --text-muted:#6B6962;
  --text-faint:#9A978F;
  --ink-gray:#45433D;
  --success:#1F8A4C;
  --warn:#B7791F;
  --error:#C2362B;
  --prism-hi:#2B2823;
  --prism-lo:#0B0A08;
  --flag-red:#C8313A;
  --flag-blue:#253F86;
  --flag-white:#FFFFFF;
  --ink-rgb:22,20,16;
  --white-rgb:255,255,255;
  --transparent:transparent;
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","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;
  --r-xs:4px;
  --r-sm:7px;
  --r-md:10px;
  --r-card:12px;
  --r-lg:16px;
  --r-pill:999px;
  --r-round:50%;
  --gutter:48px;
  --shell-width:1320px;
  --header-height:64px;
  --anchor-offset:80px;
  --toc-offset:144px;
  --size-display:clamp(52px,4.6vw,66px);
  --size-section:clamp(32px,3.8vw,52px);
  --size-body:16px;
  --weight-regular:400;
  --weight-medium:500;
  --weight-strong:600;
  --ease-ui:.2s ease;
  --ease-reveal:.35s ease;
  --shadow-window:inset 0 1px 0 rgba(var(--white-rgb),1),0 2px 6px rgba(var(--ink-rgb),.06),0 30px 60px rgba(var(--ink-rgb),.10);
  --shadow-chip:0 1px 2px rgba(var(--ink-rgb),.06),0 10px 24px -8px rgba(var(--ink-rgb),.18);
  --shadow-card:0 2px 4px rgba(var(--ink-rgb),.06),0 18px 36px -10px rgba(var(--ink-rgb),.22);
  --shadow-ink-btn:inset 0 1px 0 rgba(var(--white-rgb),.14),0 1px 2px rgba(var(--ink-rgb),.22),0 10px 22px -8px rgba(var(--ink-rgb),.40);
  --shadow-nav:0 0 0 1px var(--border),0 1px 2px rgba(var(--ink-rgb),.06);
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-offset);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(--size-body);line-height:1.6;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
[hidden]{display:none!important}
img{display:block;max-width:100%;height:auto}
svg{flex-shrink:0}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
button,a,input,summary,select,textarea{-webkit-tap-highlight-color:rgba(var(--ink-rgb),.08)}
button{border:0}
a{color:inherit;text-underline-offset:4px}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px}
h1,h2,h3,h4{font-family:var(--font-display);font-weight:var(--weight-regular);text-wrap:balance}
h1{font-size:var(--size-display);line-height:1.12;letter-spacing:-.02em;margin:0 0 32px}
h2{font-size:var(--size-section);line-height:1.2;letter-spacing:-.02em;margin:0 0 32px}
h3{font-size:24px;line-height:1.35;margin:0 0 16px}
p{margin:0 0 24px}
strong{font-weight:var(--weight-strong)}
code,kbd,pre{font-family:var(--font-mono)}
code{overflow-wrap:anywhere;font-size:.9em}
pre{max-width:100%;overflow-x:auto;padding:20px;border:1px solid var(--border);border-radius:var(--r-md);background:var(--bg-panel-2)}
pre code{overflow-wrap:normal;white-space:pre}
hr{border:0;border-top:1px solid var(--border);margin:32px 0}
.no-break{white-space:nowrap}
.shell,.wrap{width:100%;max-width:var(--shell-width);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-top:80px;padding-bottom:80px}
.section--compact{padding-top:40px;padding-bottom:40px}
.section-head{max-width:880px;margin-bottom:40px}
.section-head p{color:var(--text-muted);max-width:42em}
.prose{max-width:800px;margin-inline:auto;overflow-wrap:anywhere}
.prose h2{font-size:32px;margin-top:48px}
.prose h3{margin-top:32px}
.prose p,.prose li{line-height:1.85}
.prose li+li{margin-top:8px}
.prose img{border-radius:var(--r-md)}
.muted{color:var(--text-muted)}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums}
.flow>*+*{margin-top:24px}
.grid{display:grid;gap:24px}
.grid--three{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--five{grid-template-columns:repeat(5,minmax(0,1fr))}
.grid>*,.hero__grid>*,.footer-grid>*,.feature-browser>*{min-width:0}
.panel,.card{min-width:0;background:var(--bg-panel);border:1px solid var(--border);border-radius:var(--r-card);box-shadow:inset 0 1px 0 rgba(var(--white-rgb),1),0 12px 32px -18px rgba(var(--ink-rgb),.16)}
.panel{padding:32px}
.card{padding:24px}
.decoration-region,.firstscreen{position:relative;overflow-x:clip;max-width:100%}
.firstscreen{background:linear-gradient(180deg,var(--bg-warm) 0,var(--bg) 64%,var(--bg) 100%)}
.skip{position:absolute;left:16px;top:-60px;z-index:100;padding:8px 14px;border-radius:var(--r-pill);background:var(--accent);color:var(--bg-panel);font-size:14px;text-decoration:none}
.skip:focus{top:12px}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.icon{display:block;width:20px;height:20px}
.cta-pair{display:flex;flex-wrap:wrap;gap:12px;margin:0 0 32px}
.btn,.btn-primary,.btn-secondary{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:48px;padding:12px 24px;border:0;border-radius:var(--r-pill);font-family:var(--font-body);font-size:16px;font-weight:var(--weight-medium);line-height:1.25;text-decoration:none;transition:background-color var(--ease-ui),box-shadow var(--ease-ui),transform var(--ease-ui)}
.btn svg,.btn-primary svg,.btn-secondary svg{width:16px;height:16px}
.btn--ink,.btn-primary{background:var(--accent);color:var(--bg-panel);box-shadow:var(--shadow-ink-btn)}
.btn--ink:hover,.btn-primary:hover{background:var(--accent-dark);transform:translateY(-1px)}
.btn--line,.btn-secondary{background:var(--bg-panel);color:var(--text);box-shadow:inset 0 0 0 1px var(--border),0 1px 2px rgba(var(--ink-rgb),.05)}
.btn--line:hover,.btn-secondary:hover{box-shadow:inset 0 0 0 1px var(--text-faint),0 1px 2px rgba(var(--ink-rgb),.05)}
.btn:active,.btn-primary:active,.btn-secondary:active{transform:translateY(0)}
.btn:disabled,.btn[aria-disabled="true"]{background:var(--bg-panel-2);color:var(--text-muted);box-shadow:none;cursor:not-allowed;transform:none}
.btn--small{min-height:36px;padding:8px 16px;font-size:14px}
.topbar{position:relative;z-index:40}
.topbar__row{position:relative;z-index:43;display:flex;align-items:center;gap:32px;height:var(--header-height);flex-wrap:nowrap}
.brand{display:inline-flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);flex:none}
.brand__mark{display:block;width:28px;height:28px;flex:none}
.brand__word{font-family:var(--font-display);font-size:18px;font-weight:var(--weight-strong);letter-spacing:-.02em;line-height:1;white-space:nowrap}
.brand__zh{color:var(--text-muted);font-size:14px;font-weight:var(--weight-regular)}
.mainnav{flex:1;min-width:0}
.mainnav ul{display:flex;align-items:center;list-style:none;margin:0;padding:0;gap:2px}
.mainnav li{flex-shrink:0}
.mainnav a{display:block;padding:7px 13px;border-radius:var(--r-pill);color:var(--text-muted);font-size:14px;line-height:20px;text-decoration:none;white-space:nowrap;transition:color var(--ease-ui),background-color var(--ease-ui)}
.mainnav a:hover{color:var(--text)}
.mainnav a[aria-current="page"]{color:var(--text);background:var(--bg-panel);box-shadow:var(--shadow-nav)}
.topbar__end{margin-left:auto;display:flex;align-items:center;gap:8px;flex-shrink:0}
.langbox{position:relative}
.langsw{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;height:36px;padding:0 12px;border:0;border-radius:var(--r-pill);background:var(--transparent);color:var(--text-muted);font:inherit;font-size:14px;line-height:1;cursor:pointer}
.langsw span{white-space:nowrap}
.langsw:hover{color:var(--text)}
.langsw svg{width:15px;height:15px;flex:none}
.lang-panel{position:absolute;right:0;top:calc(100% + 10px);z-index:60;min-width:180px;padding:8px;border:1px solid var(--border);border-radius:var(--r-card);background:var(--bg-panel);box-shadow:var(--shadow-window)}
.lang-panel a{display:flex;align-items:center;width:100%;min-height:44px;padding:8px 12px;border-radius:var(--r-sm);text-decoration:none;font-size:14px}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--bg-panel-2)}
.btn-login{display:inline-flex;align-items:center;justify-content:center;height:36px;padding:0 18px;border-radius:var(--r-pill);background:var(--accent);color:var(--bg-panel);font-size:14px;font-weight:var(--weight-medium);line-height:1;text-decoration:none;box-shadow:var(--shadow-ink-btn);transition:background-color var(--ease-ui);white-space:nowrap}
.btn-login:hover{background:var(--accent-dark)}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;padding:10px;border-radius:var(--r-pill);background:var(--transparent);color:var(--text)}
.menu-toggle svg{width:22px;height:22px}
.mobile-drawer{display:none}
.nav-veil{display:none}
.footer{border-top:1px solid var(--border);background:linear-gradient(180deg,var(--bg),var(--bg-panel-2));padding-top:56px;padding-bottom:32px}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr .8fr;gap:40px}
.footer-brand p{color:var(--text-muted);font-size:14px;max-width:27em;margin-top:20px}
.footer-heading{font-size:14px;font-weight:var(--weight-medium);margin:0 0 16px}
.footer-links{display:grid;gap:6px;list-style:none;margin:0;padding:0}
.footer-links a{display:inline-flex;align-items:center;min-height:28px;color:var(--text-muted);font-size:14px;text-decoration:none}
.footer-links a:hover{color:var(--text);text-decoration:underline}
.footer-bottom{display:flex;flex-wrap:wrap;justify-content:space-between;align-items:center;gap:16px;margin-top:40px;padding-top:24px;border-top:1px solid var(--border);font-size:13px;color:var(--text-muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:20px}
.footer-legal 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{display:block;position:static;min-width:0;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:32px}
#server-status>*{min-width:0;max-width:100%}
#server-status+*{margin-top:32px}
@media(max-width:1279px){
  .topbar__row{gap:20px}
  .mainnav a{padding:7px 9px;font-size:13.5px}
}
@media(max-width:1100px){
  .mainnav{display:none}
  .topbar__end{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .mobile-drawer{position:fixed;z-index:42;top:var(--header-height);left:0;right:0;height:calc(100dvh - var(--header-height));max-height:calc(100dvh - var(--header-height));overflow-y:auto;overscroll-behavior:contain;background:var(--bg-panel);padding:20px var(--gutter) 40px;border-top:1px solid var(--border)}
  .mobile-drawer.is-open{display:block}
  .mobile-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px 16px;border-radius:var(--r-sm);text-decoration:none}
  .mobile-drawer a:hover,.mobile-drawer a[aria-current="page"],.mobile-drawer a[aria-current="true"]{background:var(--bg-panel-2);font-weight:var(--weight-medium)}
  .drawer-languages{margin-top:20px;padding-top:20px;border-top:1px solid var(--border)}
  .nav-veil{position:fixed;z-index:41;inset:var(--header-height) 0 0;background:rgba(var(--ink-rgb),.18)}
  .nav-veil.is-open{display:block}
  html.nav-open .topbar__row{background:var(--bg)}
}
@media(max-width:768px){
  :root{--gutter:20px;--size-display:40px;--size-section:32px}
  h1{font-size:40px}
  .section{padding-top:56px;padding-bottom:56px}
  .panel{padding:24px}
  .grid--three{grid-template-columns:minmax(0,1fr)}
  .grid--five{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:32px}
  .footer-brand{grid-column:1/-1}
  .topbar__row{gap:10px}
  .topbar__end{margin-left:auto;gap:4px}
  .langsw{padding:0 8px;font-size:12px}
  .brand{gap:7px}
  .brand__word{font-size:16px}
  .btn-login{padding:0 14px;font-size:13px}
}
@media(max-width:640px){
  .no-break{white-space:normal}
  .tilt,.decoration-tilt{transform:none}
  .decoration-region,.firstscreen{max-width:100%;overflow-x:clip}
  .prose h2{font-size:28px}
}
@media(max-width:380px){
  :root{--gutter:16px}
  .brand__mark{width:24px;height:24px}
  .brand__word{font-size:15px}
  .topbar__row{gap:6px}
  .langsw{gap:4px;padding:0 5px;font-size:11px}
  .btn-login{padding:0 12px}
  .topbar__end{gap:2px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition:none!important;animation:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}