:root{
  color-scheme:light;
  --bg:#F6EDDC;--bg-top:#FBF6EC;--bg-bottom:#F1E6D2;
  --panel:#FFFBF3;--panel-2:#ECE2CF;--chrome:#F5ECDD;
  --border:#DDD0B8;--border-soft:#E9DEC9;--node-line:#D2C3A8;--node-dot:#C6B594;
  --accent:#147A63;--accent-2:#4FB38F;--accent-hi:#A6DDC5;--accent-dark:#0C5847;
  --accent-08:rgba(20,122,99,.08);--accent-12:rgba(20,122,99,.12);--accent-16:rgba(20,122,99,.16);--accent-30:rgba(20,122,99,.30);--accent-40:rgba(20,122,99,.40);
  --text:#2A2219;--muted:#6E6150;--faint:#9C8D76;
  --success:#2F8A4E;--success-16:rgba(47,138,78,.16);--warn:#C27C12;--error:#B8402E;
  --ink-06:rgba(42,34,25,.06);--ink-10:rgba(42,34,25,.10);--ink-16:rgba(42,34,25,.16);--ink-28:rgba(42,34,25,.28);
  --white-90:rgba(255,255,255,.9);--white-35:rgba(255,255,255,.35);--white-12:rgba(255,255,255,.12);
  --panel-70:rgba(255,251,243,.7);--groove-60:rgba(236,226,207,.6);
  --phone-frame:#211A13;--tl-red:#E07A68;--tl-yellow:#E6B54E;--tl-green:#76B06C;
  --flag-red:#D3283A;--flag-white:#FFFFFF;--flag-blue:#2B3C86;--flag-black:#211C18;--flag-gold:#F0B323;
  --clear:transparent;
  --radius-xs:4px;--radius-s:8px;--radius-button:10px;--radius-m:12px;--radius-l:20px;--radius-pill:999px;
  --radius-phone:34px;--radius-screen:27px;
  --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","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --size-display:68px;--size-h2:40px;--size-h3:24px;--size-body:16px;--size-lead:20px;--size-small:14px;
  --gutter:24px;--content-width:1168px;--header-height:72px;--anchor-offset:88px;--toc-offset:144px;
  --grain-alpha:.03;--ease-time:.2s;
  --shadow-card:0 1px 2px var(--ink-06),0 16px 40px var(--accent-08);
  --shadow-window:0 1px 2px var(--ink-06),0 24px 60px var(--accent-12),0 70px 120px -50px var(--accent-16);
}
*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:var(--anchor-offset)}
body{font-family:var(--font-body);font-size:var(--size-body);line-height:1.6;color:var(--text);background:var(--bg);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
button,fieldset{border:0}
button{background:var(--clear)}
img{display:block;max-width:100%;height:auto}
svg{flex-shrink:0;vertical-align:middle}
ul{list-style:none}
h1,h2,h3{font-family:var(--font-display);text-wrap:balance;overflow-wrap:break-word}
h1{font-size:clamp(52px,5vw,72px);line-height:1.12;font-weight:800;letter-spacing:-.02em}
h2{font-size:var(--size-h2);line-height:1.2;font-weight:800;letter-spacing:-.02em}
h3{font-size:var(--size-h3);line-height:1.35;font-weight:700}
p{overflow-wrap:break-word}
code{font-family:var(--font-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(--radius-s)}
pre code{white-space:pre;overflow-wrap:normal}
:where(a,button,input,select,textarea,summary,[tabindex]):focus-visible{outline:2px solid var(--accent);outline-offset:3px}
[hidden]{display:none!important}
:where(.wrap,.grid,.panel,.card)>*{min-width:0}
.wrap{width:100%;max-width:var(--content-width);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-top:88px;padding-bottom:88px}
.section-head{max-width:760px;margin-bottom:32px}
.section-head p{margin-top:16px;color:var(--muted);font-size:18px}
.grid{display:grid;gap:24px}
.grid-three{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-two{grid-template-columns:repeat(2,minmax(0,1fr))}
.card,.panel{min-width:0;padding:28px;background:var(--panel);border:1px solid var(--border);border-radius:var(--radius-m);box-shadow:var(--shadow-card)}
.panel-sunken{background:var(--panel-2);box-shadow:inset 0 1px 4px var(--ink-06)}
.muted{color:var(--muted)}
.mono{font-family:var(--font-mono)}
.no-break{white-space:nowrap}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.grain{position:fixed;inset:0;width:100%;height:100%;opacity:var(--grain-alpha);pointer-events:none;z-index:60}
.shell{background:linear-gradient(180deg,var(--bg-top) 0%,var(--bg) 55%,var(--bg-bottom) 100%)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;max-width:100%;padding:10px 22px;font-family:var(--font-body);font-weight:700;white-space:nowrap;flex-shrink:0;cursor:pointer;border:1px solid var(--clear);border-radius:var(--radius-button);transition:background var(--ease-time),color var(--ease-time)}
.btn-primary{height:48px;padding:0 28px;font-size:16px;color:var(--panel);background:var(--accent);box-shadow:inset 0 1px 0 var(--white-35),0 10px 22px -8px var(--accent-40),0 1px 2px var(--ink-10)}
.btn-primary:hover,.btn-primary.is-hover{background:var(--accent-dark)}
.btn-secondary{background:var(--panel);border-color:var(--border);color:var(--text)}
.btn-secondary:hover{background:var(--panel-2)}
.btn-text{padding:0;gap:6px;font-size:16px;font-weight:600;color:var(--text)}
.btn-text .arr{display:inline-block;transition:transform var(--ease-time)}
.btn-text:hover .arr{transform:translateX(3px)}
.btn:disabled,.btn[aria-disabled="true"]{cursor:not-allowed;background:var(--panel-2);color:var(--muted);box-shadow:none;border-color:var(--border)}
.cta-row{margin-top:28px;display:flex;align-items:center;flex-wrap:wrap;gap:28px}
.badge,.fact-pill{display:inline-flex;align-items:center;gap:8px;max-width:100%;padding:4px 12px;border:1px solid var(--border);border-radius:var(--radius-pill);background:var(--panel);font-size:13px;font-weight:600;overflow-wrap:anywhere}
.badge-accent{background:var(--accent-12);color:var(--accent-dark)}
.fact-row{display:flex;flex-wrap:wrap;gap:8px}
.stat-number{display:inline-block;min-width:3ch;font-family:var(--font-mono);font-variant-numeric:tabular-nums}
.topbar{position:relative;z-index:40}
.topbar .wrap{display:flex;align-items:center;flex-wrap:nowrap;height:var(--header-height);gap:28px}
.brand{display:flex;align-items:center;gap:10px;flex-shrink:0}
.brand-mark{display:block;width:30px;height:30px}
.brand-en{font-family:var(--font-display);font-weight:800;font-size:20px;letter-spacing:-.02em;line-height:1}
.brand-zh{font-size:14px;font-weight:500;color:var(--muted);line-height:1;padding-left:10px;border-left:1px solid var(--border)}
.nav{flex:1;min-width:0}
.nav-list{display:flex;align-items:center;list-style:none;margin:0;padding:4px;gap:2px;width:max-content;max-width:100%;background:var(--groove-60);border:1px solid var(--border-soft);border-radius:var(--radius-pill)}
.nav-list a{display:flex;align-items:center;justify-content:center;padding:6px 9px;min-height:32px;font-size:14px;line-height:20px;font-weight:500;color:var(--muted);white-space:nowrap;border-radius:var(--radius-pill)}
.nav-list>li{flex-shrink:0}
.nav-more{position:relative}
.nav-more-toggle{display:flex;align-items:center;justify-content:center;gap:6px;min-height:32px;padding:6px 9px;font-size:14px;line-height:20px;color:var(--muted);white-space:nowrap;cursor:pointer;border:0;background:transparent;border-radius:var(--radius-pill)}
.nav-more-toggle:hover,.nav-more-toggle[aria-expanded="true"]{background:var(--panel);color:var(--text)}
.nav-more-panel{position:absolute;z-index:55;top:calc(100% + 8px);right:0;min-width:200px;list-style:none;margin:0;padding:6px;background:var(--panel);border:1px solid var(--border);border-radius:var(--radius-s);box-shadow:var(--shadow-card)}
.nav-more-panel a{justify-content:flex-start;min-height:44px;border-radius:var(--radius-s)}
.nav-list a:hover{color:var(--text)}
.nav-list a[aria-current="page"]{background:var(--panel);color:var(--text);font-weight:600;box-shadow:0 1px 2px var(--ink-10),0 6px 14px var(--accent-08)}
.nav-end{margin-left:auto;display:flex;align-items:center;gap:12px;flex-shrink:0}
.lang-wrap{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;height:36px;min-width:44px;width:auto;padding:0 12px;font-size:14px;white-space:nowrap;color:var(--text);border:1px solid var(--border);border-radius:var(--radius-s);background:var(--panel-70)}
.lang svg{width:15px;height:15px;color:var(--muted)}
.lang span{white-space:nowrap}
.caret{font-size:11px;color:var(--muted)}
.lang-panel{position:absolute;z-index:55;top:calc(100% + 8px);right:0;min-width:180px;padding:6px;background:var(--panel);border:1px solid var(--border);border-radius:var(--radius-s);box-shadow:var(--shadow-card)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--radius-s)}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--panel-2)}
.btn-login{display:inline-flex;align-items:center;justify-content:center;height:36px;min-width:60px;padding:0 18px;font-size:14px;font-weight:600;white-space:nowrap;color:var(--panel);background:var(--text);border-radius:var(--radius-s);box-shadow:inset 0 1px 0 var(--white-12),0 4px 12px var(--ink-16)}
.btn-login:hover{background:var(--accent-dark)}
.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(--radius-s);background:var(--panel)}
.menu-line{display:block;width:20px;height:2px;background:currentColor}
.menu-toggle[aria-expanded="true"] .menu-line:first-child{transform:translateY(6px) rotate(45deg)}
.menu-toggle[aria-expanded="true"] .menu-line:nth-child(2){opacity:0}
.menu-toggle[aria-expanded="true"] .menu-line:last-child{transform:translateY(-6px) rotate(-45deg)}
.nav-drawer{position:fixed;top:var(--header-height);right:0;left:0;z-index:39;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)}
.nav-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px 16px;border-radius:var(--radius-s)}
.nav-drawer a[aria-current="page"],.nav-drawer a:hover{background:var(--panel-2)}
.drawer-languages{padding-top:16px;margin-top:16px;border-top:1px solid var(--border)}
.nav-veil{position:fixed;inset:var(--header-height) 0 0;z-index:38;background:var(--ink-28)}
html.nav-open{overflow:hidden}
html.nav-open .topbar{background:var(--bg-top)}
.site-footer{padding-top:56px;padding-bottom:28px;border-top:1px solid var(--border);background:var(--panel-2)}
.footer-grid{display:grid;grid-template-columns:1.1fr 1fr 1fr;gap:48px}
.footer-brand p{max-width:300px;margin-top:16px;color:var(--muted);font-size:14px}
.footer-heading{font-size:14px;font-weight:700;margin-bottom:12px}
.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 16px}
.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:8px 20px;margin-top:32px;padding-top:20px;border-top:1px solid var(--border)}
.footer-bottom{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:16px;margin-top:20px;color:var(--muted);font-size:13px}
.footer-legal{display:flex;flex-wrap:wrap;gap:20px}
.prose{max-width:800px;margin-inline:auto;line-height:1.9}
.prose p,.prose ul,.prose ol,.prose pre{margin-block:18px}
.prose h2{margin-top:56px;margin-bottom:20px;font-size:32px}
.prose h3{margin-top:32px;margin-bottom:14px}
.prose ul{list-style:disc;padding-left:24px}
.prose ol{padding-left:24px}
.prose a{text-decoration:underline;text-underline-offset:3px}
.prose li+li{margin-top:8px}
.reveal{transition:opacity .35s ease,transform .35s ease}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:relative;display:block;min-width:0;min-height:44px;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:32px}
#server-status+*{margin-top:32px}
@media(min-width:1001px){.nav-drawer,.nav-veil{display:none!important}}
@media(max-width:1260px){.topbar .wrap{gap:18px}.nav-list a{padding-inline:9px}}
@media(max-width:1100px){.nav-list a{padding-inline:7px;font-size:13px}.topbar .wrap{gap:12px}.nav-end{gap:8px}}
@media(max-width:1000px){.nav{display:none}.menu-toggle{display:inline-flex}.nav-end{margin-left:auto}.footer-grid{gap:24px}}
@media(max-width:768px){h1{font-size:40px}.grid-three{grid-template-columns:minmax(0,1fr)}.section{padding-top:56px;padding-bottom:56px}h2{font-size:32px}}
@media(max-width:640px){
  :root{--gutter:20px}
  .no-break{white-space:normal}
  .grid-two,.footer-grid{grid-template-columns:minmax(0,1fr)}
  .brand-zh{display:none}
  .topbar .wrap{gap:8px}
  .nav-end{margin-left:auto;gap:6px}
  .lang{padding-inline:8px}
  .lang span:not(.caret){display:none}
  .btn-login{padding-inline:12px}
  .card,.panel{padding:20px}
  .tilt,[data-tilt]{transform:none}
  .decorative-region{overflow-x:clip;max-width:100%}
  .footer-grid{gap:32px}
}
@media(max-width:360px){:root{--gutter:16px}.brand-en{font-size:18px}.brand{gap:6px}.brand-mark{width:26px;height:26px}.nav-end{gap:4px}.btn-login{padding-inline:10px;min-width:52px}}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation:none!important;transition:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}