:root {
  --bg:#F6EEE0;
  --bg-hi:#FAF4EA;
  --bg-lo:#F1E6D4;
  --panel:#FFFCF6;
  --panel-2:#EFE5D3;
  --panel-3:#F8F1E6;
  --border:#E2D6C2;
  --border-soft:#EBE1D0;
  --rule:#E3D6C1;
  --mark:#B3A38A;
  --accent:#2E44C6;
  --accent-dark:#1F2F94;
  --text:#221A13;
  --ink-2:#3A2E24;
  --muted:#6E6152;
  --faint:#9C8E7A;
  --ghost:#C6B9A5;
  --success:#2F7D4F;
  --warn:#B7791F;
  --error:#B8382C;
  --on-ink:#FFFCF6;
  --clear:transparent;
  --hl:rgba(255,255,255,.9);
  --hl-ink:rgba(255,252,246,.18);
  --sheen:rgba(255,252,246,.9);
  --sheen-0:rgba(255,252,246,0);
  --ink-hair:rgba(34,26,19,.06);
  --ink-hair-2:rgba(34,26,19,.10);
  --veil-color:rgba(34,26,19,.28);
  --accent-shadow:rgba(46,68,198,.35);
  --accent-shadow-soft:rgba(46,68,198,.14);
  --shadow-frame:0 2px 6px rgba(46,68,198,.04),0 34px 90px -34px rgba(46,68,198,.08);
  --shadow-card:0 1px 2px rgba(34,26,19,.05),0 14px 30px -18px rgba(46,68,198,.10),0 44px 84px -30px rgba(46,68,198,.12);
  --shadow-float:0 2px 5px rgba(34,26,19,.06),0 16px 32px -14px rgba(46,68,198,.22);
  --shadow-ink:0 10px 18px -8px rgba(34,26,19,.55);
  --shadow-ink-sm:0 6px 12px -6px rgba(34,26,19,.5);
  --shadow-btn:0 2px 4px rgba(34,26,19,.12),0 14px 28px -14px rgba(34,26,19,.55);
  --flag-red:#C8352F;
  --flag-blue:#253A7A;
  --flag-white:#FFFFFF;
  --flag-edge:rgba(34,26,19,.16);
  --r-card:12px;
  --r-md:10px;
  --r-sm:8px;
  --r-xs:7px;
  --r-focus:6px;
  --r-flag:3px;
  --r-circle:50%;
  --r-pill:999px;
  --f-display:"Inter","Noto Sans SC","Noto Sans JP","Noto Sans KR","PingFang SC","Hiragino Sans","Microsoft YaHei",system-ui,sans-serif;
  --f-body:"Inter","Noto Sans SC","Noto Sans JP","Noto Sans KR","PingFang SC","Hiragino Sans","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --f-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --fs-body:16px;
  --fs-small:14px;
  --fs-h1:64px;
  --fs-h2:44px;
  --fs-h3:24px;
  --weight-display:800;
  --tracking-display:-.03em;
  --gutter:24px;
  --rail:min(1360px,calc(100% - 32px));
  --header-height:76px;
  --anchor-gap:92px;
  --toc-offset:16px;
  --toc-landing:100px;
  --ease:cubic-bezier(.22,.8,.24,1);
  --fast:.2s;
  --reveal-time:.35s;
  --grain:url("data:image/svg+xml;utf8,%3Csvg xmlns='http://www.w3.org/2000/svg' width='180' height='180'%3E%3Cfilter id='g'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.85' numOctaves='3' stitchTiles='stitch'/%3E%3CfeColorMatrix values='0 0 0 0 .13 0 0 0 0 .10 0 0 0 0 .07 0 0 0 .55 0'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23g)' opacity='.06'/%3E%3C/svg%3E");
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-gap);scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--f-body);font-size:var(--fs-body);line-height:1.5;-webkit-font-smoothing:antialiased;overflow-x:clip}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
button:disabled{cursor:not-allowed}
img{display:block;max-width:100%;height:auto}
svg{display:block;flex-shrink:0}
[hidden]{display:none!important}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:var(--r-focus)}
h1,h2,h3{font-family:var(--f-display);text-wrap:balance;overflow-wrap:break-word}
h1{font-size:var(--fs-h1);font-weight:var(--weight-display);line-height:1.1;letter-spacing:var(--tracking-display)}
h2{font-size:var(--fs-h2);font-weight:var(--weight-display);line-height:1.15;letter-spacing:var(--tracking-display)}
h3{font-size:var(--fs-h3);line-height:1.35;letter-spacing:-.02em}
:lang(zh-CN) h1,:lang(zh-CN) h2,:lang(zh-TW) h1,:lang(zh-TW) h2,:lang(ja) h1,:lang(ja) h2,:lang(ko) h1,:lang(ko) h2{letter-spacing:-.02em}
p{margin:0 0 1.25em}
code{font-family:var(--f-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-sm)}
pre code{overflow-wrap:normal;white-space:pre}
table{border-collapse:collapse}
th,td{word-break:keep-all}
.no-break{white-space:nowrap}
.kw,.text-link{color:var(--accent)}
.text-link{display:inline-block;min-height:24px}
.text-link:hover{text-decoration:underline}
.muted{color:var(--muted)}
.mono{font-family:var(--f-mono);font-variant-numeric:tabular-nums}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
.page{position:relative;max-width:100%;overflow-x:clip;background-image:var(--grain),linear-gradient(180deg,var(--bg-hi) 0,var(--bg-lo) 860px,var(--bg) 1100px);background-size:180px 180px,100% 100%;background-repeat:repeat,no-repeat}
.rails{position:absolute;inset:0;margin-inline:auto;width:var(--rail);border-left:1px solid var(--rule);border-right:1px solid var(--rule);pointer-events:none;z-index:0}
.shell{position:relative;z-index:1;width:var(--rail);margin-inline:auto;min-width:0}
.wrap{position:relative;width:100%;max-width:1240px;margin-inline:auto;padding-inline:var(--gutter);min-width:0}
.section{padding-top:72px;padding-bottom:72px}
.section-head{text-align:center;margin-bottom:40px}
.section-title{margin:20px auto 12px;max-width:18em;font-size:var(--fs-h2);font-weight:var(--weight-display);line-height:1.15;letter-spacing:var(--tracking-display)}
.section-sub{margin:0 auto;max-width:34em;font-size:17px;color:var(--muted)}
.seam{position:relative;z-index:2;height:1px;background:var(--rule)}
.reg{position:absolute;top:0;width:15px;height:15px;transform:translate(-50%,-50%)}
.reg::before,.reg::after{content:"";position:absolute;background:var(--mark)}
.reg::before{inset:7px 0 auto;height:1px}
.reg::after{inset:0 auto 0 7px;width:1px}
.reg-l{left:calc(50% - var(--rail)/2)}
.reg-r{left:calc(50% + var(--rail)/2 - 1px)}
.panel{min-width:0;padding:28px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-card);box-shadow:inset 0 1px 0 var(--hl),var(--shadow-frame)}
.grid-three{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.grid-five{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:16px}
.grid-three>*,.grid-five>*{min-width:0}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:44px;padding:10px 24px;border:1px solid var(--clear);border-radius:var(--r-pill);font-weight:600;line-height:1.4;transition:background-color var(--fast) ease,transform var(--fast) ease;flex-shrink:0}
.btn-main,.btn-primary{height:52px;background:var(--text);color:var(--on-ink);font-size:16px;box-shadow:inset 0 1px 0 var(--hl-ink),var(--shadow-btn)}
.btn-main:hover,.btn-primary:hover{background:var(--ink-2)}
.btn-ghost,.btn-secondary{min-height:48px;background:var(--panel-3);border-color:var(--border);color:var(--text);font-size:15px;font-weight:500;box-shadow:inset 0 1px 0 var(--hl)}
.btn-ghost:hover,.btn-secondary:hover{background:var(--panel-2)}
.btn:active{transform:translateY(1px)}
.btn:disabled,.btn[aria-disabled="true"]{background:var(--panel-2);color:var(--muted);box-shadow:none;border-color:var(--border);pointer-events:none}
.btn-wide{width:100%}
.topbar{position:relative;height:var(--header-height);display:flex;align-items:center;flex-wrap:nowrap;gap:32px;padding-inline:60px;z-index:60}
#site-header{position:relative;z-index:60}
.brand{display:inline-flex;align-items:center;gap:10px;font-family:var(--f-display);font-weight:800;font-size:19px;letter-spacing:-.02em;color:var(--text);flex-shrink:0;min-height:44px;white-space:nowrap}
.brand-logo{width:30px;height:30px;border-radius:var(--r-circle);flex-shrink:0}
.desktop-nav{flex:1;min-width:0}
.nav{display:flex;align-items:center;list-style:none;margin:0;padding:0;gap:18px;justify-content:center}
.nav-more{position:relative}
.nav-more-toggle{display:flex;align-items:center;min-height:44px;padding:0;border:0;background:transparent;font-size:14px;color:var(--muted);white-space:nowrap;cursor:pointer}
.nav-more-menu[hidden]{display:none}
.nav-more-menu{position:absolute;z-index:80;right:0;top:100%;width:max-content;min-width:180px;max-width:calc(100vw - 32px);padding:8px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--shadow-float)}
.nav .nav-more-menu a{display:flex;min-height:44px;padding:8px 12px;border-radius:var(--r-focus)}
.nav-more-menu a:hover{background:var(--panel-2)}
.nav a{display:inline-flex;align-items:center;min-height:32px;font-size:15px;font-weight:500;color:var(--muted);white-space:nowrap;transition:color var(--fast) ease}
.nav a:hover{color:var(--text)}
.nav a[aria-current="page"]{color:var(--text);font-weight:700}
.top-actions{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-width:44px;min-height:38px;width:auto;padding:6px 2px;border:0;background:var(--clear);font-size:14px;color:var(--muted)}
.lang span{white-space:nowrap}
.lang:hover{color:var(--text)}
.language-menu{position:absolute;z-index:80;right:0;top:calc(100% + 8px);width:180px;padding:8px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--shadow-float)}
.language-menu a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-focus)}
.language-menu a:hover,.language-menu a[aria-current="true"]{background:var(--panel-2)}
.login{display:inline-flex;align-items:center;justify-content:center;gap:6px;height:38px;padding:0 14px 0 18px;border-radius:var(--r-pill);background:var(--text);color:var(--on-ink);font-size:14px;font-weight:600;box-shadow:inset 0 1px 0 var(--hl-ink),var(--shadow-ink-sm);white-space:nowrap;transition:background-color var(--fast) ease}
.login:hover{background:var(--ink-2)}
.menu-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;padding:10px;border:1px solid var(--border);border-radius:var(--r-sm);background:var(--panel);color:var(--text)}
.menu-line{display:block;width:20px;height:2px;background:currentColor}
.mobile-drawer{position:fixed;top:var(--header-height);right:0;left:0;z-index:55;height:calc(100dvh - var(--header-height));max-height:calc(100dvh - var(--header-height));overflow-y:auto;overscroll-behavior:contain;padding:16px var(--gutter) 32px;background:var(--panel);border-top:1px solid var(--border)}
.mobile-drawer a{display:flex;align-items:center;width:100%;min-height:48px;padding:12px 16px;border-bottom:1px solid var(--border-soft)}
.mobile-drawer a[aria-current]{background:var(--panel-2);font-weight:700}
.drawer-languages{margin-top:20px;border-top:1px solid var(--border)}
.menu-veil{position:fixed;inset:var(--header-height) 0 0;z-index:50;border:0;background:var(--veil-color)}
html.nav-open{overflow:hidden}
.site-footer{position:relative;border-top:1px solid var(--rule);background:var(--panel-2);padding-top:48px;padding-bottom:28px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:48px}
.footer-brand{min-width:0}
.footer-brand p{max-width:27em;margin-top:16px;color:var(--muted);font-size:14px;line-height:1.8}
.footer-heading{font-size:14px;font-weight:700;margin:0 0 16px}
.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px 16px;margin:0;padding:0;list-style:none}
.footer-links a,.footer-languages a,.footer-legal a{display:inline-flex;align-items:center;min-height:28px;font-size:14px;color:var(--muted)}
.footer-links a:hover,.footer-languages a:hover,.footer-legal a:hover{color:var(--text);text-decoration:underline}
.footer-languages{display:flex;flex-wrap:wrap;gap:12px 24px;margin-top:32px;padding-top:24px;border-top:1px solid var(--border)}
.footer-bottom{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px;margin-top:20px;font-size:13px;color:var(--muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:16px}
.reveal{transition:opacity var(--reveal-time) ease,transform var(--reveal-time) ease}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
.prose{max-width:78ch;margin-inline:auto;min-width:0;line-height:1.85;overflow-wrap:break-word}
.prose h2{font-size:32px;margin:48px 0 20px}
.prose h3{margin:32px 0 16px}
.prose a:not(.btn){color:var(--accent);text-decoration:underline;text-underline-offset:3px}
.prose li{margin-block:8px}
.prose>*{max-width:100%}
.decorated{position:relative;overflow-x:clip}
#server-status{position:relative;display:block;width:100%;min-width:0;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:32px}
#server-status+*{margin-top:32px}
@media(min-width:981px){.mobile-drawer,.menu-veil{display:none!important}}
@media(max-width:1240px){.nav{gap:16px}.topbar{gap:24px;padding-inline:40px}}
@media(max-width:1180px){.nav{gap:15px}.nav a{font-size:14px}.topbar{gap:18px;padding-inline:28px}.top-actions{gap:12px}}
@media(max-width:980px){.desktop-nav{display:none}.top-actions{margin-left:auto}.menu-toggle{display:flex}.footer-grid{grid-template-columns:1fr 1fr}.footer-brand{grid-column:1/-1}.grid-five{grid-template-columns:repeat(3,minmax(0,1fr))}}
@media(max-width:768px){
  :root{--rail:calc(100% - 24px);--header-height:64px;--anchor-gap:80px;--fs-h1:40px;--fs-h2:30px;--gutter:20px}
  .topbar{height:var(--header-height);padding-inline:16px;gap:12px}
  .section{padding-top:48px;padding-bottom:48px}
  .section-title{font-size:30px}
  .grid-three{grid-template-columns:minmax(0,1fr)}
  .grid-five{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-grid{gap:28px}
  .prose h2{font-size:28px}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .tilt,[data-tilt]{transform:none}
  .decorated>*{max-width:100%}
  .lang span{display:none}
  .top-actions{gap:8px;margin-left:auto}
  .brand{font-size:17px;gap:7px}
  .brand-logo{width:27px;height:27px}
  .login{padding-inline:13px}
  .topbar{padding-inline:12px}
  .footer-grid{grid-template-columns:minmax(0,1fr)}
  .footer-brand{grid-column:auto}
  .panel{padding:22px}
}
@media(max-width:420px){.brand{font-size:16px}.top-actions{gap:4px}.topbar{gap:8px}.headline{font-size:34px}}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none;transition:none}
  .btn,.login,.nav a{transition:none}
}