:root{
  --bg:#F8F1E5;--panel:#FFFBF4;--panel-2:#EFE6D6;--border:#E2D6C2;--border-strong:#CDBFA8;
  --accent:#2F54FF;--accent-2:#4F8BFF;--accent-dark:#1A33C9;--text:#2A2118;--text-hover:#3B2F23;--muted:#6E6152;
  --success:#2E8B57;--warn:#C98A12;--error:#C8402E;--hero-top:#FBF6EC;--hero-bottom:#F2E9D9;--on-accent:#FFFBF4;--on-dark:#F8F1E5;
  --a04:rgba(47,84,255,.04);--a06:rgba(47,84,255,.06);--a08:rgba(47,84,255,.08);--a10:rgba(47,84,255,.10);--a12:rgba(47,84,255,.12);--a14:rgba(47,84,255,.14);--a22:rgba(47,84,255,.22);--a28:rgba(47,84,255,.28);--a32:rgba(47,84,255,.32);--a55:rgba(47,84,255,.55);
  --ok-a16:rgba(46,139,87,.16);--ink-a04:rgba(42,33,24,.04);--ink-a06:rgba(42,33,24,.06);--ink-a10:rgba(42,33,24,.10);--ink-a28:rgba(42,33,24,.28);
  --hi:rgba(255,255,255,.92);--hi-soft:rgba(255,255,255,.34);--hi-dim:rgba(255,255,255,.12);--clear:transparent;
  --flag-red:#D7262B;--flag-blue:#2B3D8F;--flag-white:#FFFFFF;--flag-edge:rgba(42,33,24,.18);
  --r-xs:5px;--r-s:6px;--r-m:8px;--r-l:10px;--r-xl:12px;--r-round:999px;
  --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;
  --fs-xs:11px;--fs-code:11.5px;--fs-small:12.5px;--fs-label:13px;--fs-trust:13.5px;--fs-nav:14px;--fs-body:15px;--fs-button:15.5px;--fs-brand:18px;--fs-lead:20px;
  --fs-h1:clamp(52px,4.72vw,68px);--fs-h2:clamp(26px,3vw,38px);--fs-h3:22px;--fs-mobile-h1:38px;
  --weight-normal:400;--weight-medium:500;--weight-semibold:600;--weight-bold:700;--weight-brand:800;--weight-display:900;
  --gutter:48px;--content-width:1280px;--reading-width:800px;--header-height:64px;--anchor-offset:80px;--toc-offset:88px;
  --section-space:80px;--card-pad:24px;--gap:24px;--ease:ease;--fast:.15s;--reveal-time:.35s;
  --shadow-paper:inset 0 1px 0 var(--hi),0 18px 40px -18px var(--a14),0 40px 90px -30px var(--a12);
  --shadow-small:inset 0 1px 0 var(--hi),0 10px 24px -16px var(--a14);
  --grain:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='160' height='160'><filter id='g'><feTurbulence type='fractalNoise' baseFrequency='.92' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 .16  0 0 0 0 .13  0 0 0 0 .09  0 0 0 .6 0'/></filter><rect width='100%' height='100%' filter='url(%23g)'/></svg>");
}
*,*::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(--fs-body);line-height:1.6;-webkit-font-smoothing:antialiased}
body::after{content:"";position:fixed;inset:0;pointer-events:none;z-index:60;background-image:var(--grain);background-size:160px 160px;opacity:.11}
[hidden]{display:none!important}
a{color:inherit;text-decoration:none}
img{max-width:100%;height:auto}
svg{flex-shrink:0}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;padding:0;cursor:pointer}
button:disabled,.btn[aria-disabled="true"]{opacity:.55;cursor:not-allowed;pointer-events:none}
:where(a,button,summary,input,select,textarea,[tabindex]):focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:var(--r-s)}
p,figure{margin:0}
ul,ol{padding-left:1.5em}
h1,h2,h3,h4{font-family:var(--font-display);color:var(--text);overflow-wrap:break-word}
h1{margin:18px 0 0;font-weight:var(--weight-display);font-size:var(--fs-h1);line-height:1.1;letter-spacing:-.02em}
h2{margin:0 0 24px;font-size:var(--fs-h2);font-weight:var(--weight-display);line-height:1.2;letter-spacing:-.02em}
h3{margin:0 0 16px;font-size:var(--fs-h3);font-weight:var(--weight-bold);line-height:1.35}
h4{font-size:var(--fs-brand)}
.no-break{white-space:nowrap}
.h1-line{display:block}
.wrap{width:100%;max-width:var(--content-width);margin-inline:auto;padding-inline:var(--gutter)}
.reading-wrap{max-width:var(--reading-width);margin-inline:auto;min-width:0}
.section{padding-top:var(--section-space);padding-bottom:var(--section-space);overflow-x:clip}
.section-head{margin-bottom:32px;max-width:800px}
.section-head p,.muted{color:var(--muted)}
.lead{font-size:var(--fs-lead);line-height:1.75}
.mono,code,pre{font-family:var(--font-mono)}
code{overflow-wrap:anywhere;background:var(--panel-2);border-radius:var(--r-xs);padding:2px 5px}
pre{overflow-x:auto;max-width:100%;padding:20px;border:1px solid var(--border);border-radius:var(--r-m);background:var(--panel-2)}
pre code{padding:0;background:var(--clear);overflow-wrap:normal}
.prose{min-width:0;line-height:1.9}
.prose p,.prose ul,.prose ol,.prose pre{margin-block:0 24px}
.prose h2{margin-top:48px}
.prose h3{margin-top:32px}
.prose a:not(.btn){color:var(--accent-dark);text-decoration:underline;text-underline-offset:4px}
.prose li+li{margin-top:8px}
.grid{display:grid;gap:var(--gap)}
.grid-3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:var(--gap)}
.grid-5{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:16px}
.grid>*,.grid-3>*,.grid-5>*,.wrap>*,.prose>*{min-width:0}
.panel,.card{min-width:0;padding:var(--card-pad);border:1px solid var(--border);border-radius:var(--r-l);background:var(--panel);box-shadow:var(--shadow-small)}
.panel-inset{background:var(--panel-2);border:1px solid var(--border);border-radius:var(--r-m);padding:16px}
.ico{width:16px;height:16px;flex:none;display:block}
.cta-row{display:flex;flex-wrap:wrap;gap:12px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:48px;padding:10px 22px;border-radius:var(--r-l);font-size:var(--fs-button);font-weight:var(--weight-bold);letter-spacing:.01em;white-space:nowrap;flex-shrink:0;transition:transform var(--fast) var(--ease),background var(--fast) var(--ease)}
.btn:hover{transform:translateY(-1px)}
.btn-primary{color:var(--on-accent);background:linear-gradient(180deg,var(--accent-2) -30%,var(--accent) 62%);box-shadow:inset 0 1px 0 var(--hi-soft),0 0 0 1px var(--accent),0 12px 26px -8px var(--a32)}
.btn-primary:hover{background:linear-gradient(180deg,var(--accent),var(--accent-dark))}
.btn-dark{color:var(--on-dark);background:var(--text);box-shadow:inset 0 1px 0 var(--hi-dim),0 12px 24px -12px var(--ink-a28)}
.btn-dark:hover{background:var(--text-hover)}
.btn-secondary{background:var(--panel);border:1px solid var(--border);box-shadow:inset 0 1px 0 var(--hi)}
.btn-secondary:hover{border-color:var(--accent)}
.btn-small{min-height:36px;padding:6px 14px;font-size:var(--fs-nav)}
.text-link{display:inline-flex;align-items:center;gap:8px;min-height:24px;color:var(--accent-dark);font-weight:var(--weight-semibold)}
.topbar{position:relative;z-index:40;background:var(--hero-top)}
.topbar-in{display:flex;align-items:center;flex-wrap:nowrap;min-height:var(--header-height);gap:20px}
.brand{display:inline-flex;align-items:center;gap:9px;flex:none}
.brand-mark{width:28px;height:28px;display:block}
.brand-en{font-family:var(--font-display);font-weight:var(--weight-brand);font-size:var(--fs-brand);letter-spacing:-.02em;line-height:1}
.brand-zh{font-size:var(--fs-label);font-weight:var(--weight-medium);color:var(--muted);padding-left:9px;border-left:1px solid var(--border);line-height:1}
.mainnav{flex:1;min-width:0;overflow-x:auto;scrollbar-width:none}
.mainnav::-webkit-scrollbar{display:none}
.mainnav ul{display:flex;align-items:center;gap:2px;list-style:none;margin:0;padding:0}
.mainnav li{flex-shrink:0}
.mainnav a{display:inline-flex;align-items:center;gap:6px;height:36px;padding:0 10px;border-radius:var(--r-s);font-size:var(--fs-nav);font-weight:var(--weight-medium);color:var(--muted);white-space:nowrap}
.mainnav a:hover{color:var(--text);background:var(--ink-a04)}
.mainnav a[aria-current="page"]{color:var(--text);font-weight:var(--weight-semibold);background:var(--panel);box-shadow:inset 0 0 0 1px var(--border),inset 0 1px 0 var(--hi)}
.mainnav a[aria-current="page"] .ico{color:var(--accent)}
.top-right{display:flex;align-items:center;gap:8px;flex-shrink:0;margin-left:auto}
.lang-switch{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;height:36px;padding:0 10px;border-radius:var(--r-s);font-size:var(--fs-nav);color:var(--muted);white-space:nowrap}
.lang span{white-space:nowrap}
.lang:hover{color:var(--text);background:var(--ink-a04)}
.lang-caret{font-size:var(--fs-xs);line-height:1}
.lang-panel{position:absolute;right:0;top:calc(100% + 8px);z-index:55;min-width:172px;padding:6px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-m);box-shadow:var(--shadow-paper)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-s);white-space:nowrap}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--panel-2);color:var(--accent-dark)}
.login{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:36px;padding:6px 14px;border-radius:var(--r-m);background:var(--panel);border:1px solid var(--border);font-size:var(--fs-nav);font-weight:var(--weight-semibold);white-space:nowrap;box-shadow:inset 0 1px 0 var(--hi),0 6px 14px -6px var(--a14)}
.login:hover{border-color:var(--border-strong)}
.menu-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;border:1px solid var(--border);border-radius:var(--r-m);background:var(--panel)}
.menu-line{display:block;width:20px;height:2px;background:currentColor}
.mobile-drawer{display:none}
.menu-veil{display:none}
html.nav-open{overflow:hidden}
.site-footer{border-top:1px solid var(--border);background:var(--panel-2);padding-top:56px;padding-bottom:28px}
.footer-grid{display:grid;grid-template-columns:1.35fr 1fr 1fr 1fr;gap:40px}
.footer-grid>*{min-width:0}
.footer-brand p{margin-top:20px;max-width:300px;color:var(--muted)}
.footer-title{margin:0 0 16px;font-size:var(--fs-nav);font-weight:var(--weight-bold)}
.footer-links{display:grid;gap:4px;list-style:none;padding:0;margin:0}
.footer-links a{display:inline-flex;align-items:center;min-height:28px;color:var(--muted);overflow-wrap:anywhere}
.footer-links a:hover{color:var(--accent-dark)}
.footer-bottom{display:flex;flex-wrap:wrap;justify-content:space-between;gap:16px;margin-top:40px;padding-top:24px;border-top:1px solid var(--border);font-size:var(--fs-label);color:var(--muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:20px}
.footer-legal a{display:inline-flex;align-items:center;min-height:24px}
.reveal{transition:opacity var(--reveal-time) var(--ease),transform var(--reveal-time) var(--ease)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:static;display:block;min-width:0;max-width:100%;min-height:160px;overflow:hidden;margin-block:24px 32px}
#server-status+*{margin-top:24px}
[data-counter]{display:inline-block;min-width:3ch;font-variant-numeric:tabular-nums;text-align:right}
[data-counter="14"]{min-width:2ch}
@media(max-width:1080px){
  .topbar-in{gap:12px}
  .mainnav a{padding-inline:8px}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:960px){
  .mainnav{display:none}
  .menu-toggle{display:flex}
  .top-right{margin-left:auto}
  .mobile-drawer{position:fixed;top:var(--header-height);inset-inline:0;z-index:35;height:calc(100dvh - var(--header-height));max-height:calc(100dvh - var(--header-height));overflow-y:auto;overscroll-behavior:contain;background:var(--panel);padding:16px var(--gutter) 32px}
  .mobile-drawer:not([hidden]){display:block}
  .mobile-drawer ul{list-style:none;margin:0;padding:0}
  .mobile-drawer a{display:flex;align-items:center;gap:10px;width:100%;min-height:44px;padding:12px;border-radius:var(--r-m)}
  .mobile-drawer a:hover,.mobile-drawer a[aria-current]{background:var(--panel-2);color:var(--accent-dark)}
  .drawer-languages{margin-top:16px;padding-top:16px;border-top:1px solid var(--border)}
  .menu-veil:not([hidden]){display:block;position:fixed;top:var(--header-height);inset-inline:0;bottom:0;z-index:30;background:var(--ink-a28)}
}
@media(max-width:768px){
  :root{--gutter:20px;--section-space:48px;--card-pad:20px}
  h1{font-size:var(--fs-mobile-h1)}
  .grid-3{grid-template-columns:1fr}
  .grid-5{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-grid{gap:28px}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .tilt,.float{transform:none}
  .section,.hero,.hero-halo{max-width:100%}
  .topbar-in{gap:8px}
  .top-right{gap:4px;margin-left:auto}
  .brand{gap:6px}
  .brand-en{font-size:var(--fs-body)}
  .brand-mark{width:24px;height:24px}
  .brand-zh{display:none}
  .lang{padding-inline:6px;font-size:var(--fs-small)}
  .login{padding-inline:10px;font-size:var(--fs-label)}
  .login .ico{display:none}
  .footer-grid{grid-template-columns:1fr 1fr}
  .footer-brand{grid-column:1/-1}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition:none!important;animation:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
  .btn:hover{transform:none}
}