:root {
  --bg:#F8FAF9;
  --panel:#FFFFFF;
  --panel-2:#EEF3F0;
  --border:#DDE5E0;
  --border-strong:#C8D4CD;
  --accent:#1FC27F;
  --accent-hover:#19B072;
  --accent-dark:#0B7A4E;
  --accent-soft:#D3F5E3;
  --accent-tint:#EEFAF4;
  --text:#0F1A14;
  --muted:#5B6B62;
  --success:#16A05A;
  --warn:#D9890B;
  --error:#D2453A;
  --signal:#F5D547;
  --ink-2:#1A2B22;
  --on-ink:#FFFFFF;
  --on-ink-muted:#A7BCB0;
  --on-mint-muted:#2F5544;
  --board-1:#7FD9AC;
  --board-2:#B3E9CD;
  --board-3:#A3D8BC;
  --board-4:#3A6B54;
  --flag-red:#D52B3A;
  --flag-blue:#23408E;
  --flag-white:#FFFFFF;
  --flag-edge:rgba(15,26,20,.14);
  --atmo:rgba(31,194,127,.055);
  --glow:rgba(31,194,127,.10);
  --sheen:rgba(255,255,255,.40);
  --scan:rgba(31,194,127,.34);
  --ink-edge:rgba(255,255,255,.10);
  --coupon-ink:rgba(15,26,20,.30);
  --veil:rgba(15,26,20,.30);
  --clear:transparent;
  --shadow-win:0 40px 80px -28px rgba(31,194,127,.26),0 12px 28px -12px rgba(11,122,78,.14),0 1px 2px rgba(15,26,20,.05);
  --shadow-card:0 22px 44px -18px rgba(11,122,78,.32),0 2px 6px rgba(15,26,20,.06);
  --shadow-ink:0 26px 50px -20px rgba(0,0,0,.55);
  --shadow-btn:0 12px 24px -12px rgba(31,194,127,.70),inset 0 1px 0 rgba(255,255,255,.35);
  --shadow-chip:0 12px 26px -12px rgba(11,122,78,.38),0 1px 2px rgba(15,26,20,.05);
  --shadow-seg:0 4px 12px -6px rgba(11,122,78,.30),0 1px 2px rgba(15,26,20,.06);
  --hl-inner:inset 0 0 0 1px rgba(255,255,255,.85);
  --radius-xs:6px;
  --radius-s:8px;
  --radius:10px;
  --radius-l:12px;
  --radius-board:20px;
  --radius-pill:999px;
  --radius-round:50%;
  --radius-logo:9px;
  --font-display:"Inter","Noto Sans SC","PingFang SC","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;
  --size-body:16px;
  --size-display:64px;
  --size-section:40px;
  --weight-display:900;
  --gutter:24px;
  --page-width:1368px;
  --header-height:64px;
  --anchor-offset:80px;
  --toc-offset:88px;
  --ease:cubic-bezier(.2,.65,.3,1);
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:var(--anchor-offset)}
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}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
button:disabled{cursor:not-allowed}
a,button,summary{touch-action:manipulation}
a:focus-visible,button:focus-visible,summary:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,[tabindex]:focus-visible{outline:2px solid var(--accent-dark);outline-offset:3px}
p,h1,h2,h3,h4,ul,ol,blockquote{margin:0}
ul{padding:0;list-style:none}
img{display:block;max-width:100%;height:auto}
svg{flex:none;vertical-align:middle}
[hidden]{display:none!important}
.wrap{width:100%;max-width:var(--page-width);padding-inline:var(--gutter);margin-inline:auto}
.wrap > *,section > *,article > *,main > *,[class*="grid"] > *{min-width:0}
.no-break{white-space:nowrap}
.defs{position:absolute;width:0;height:0;overflow:hidden}
h1{font-family:var(--font-display);font-size:clamp(52px,4.7vw,68px);font-weight:var(--weight-display);line-height:1.1;letter-spacing:-.02em}
h2{font-family:var(--font-display);font-size:var(--size-section);font-weight:var(--weight-display);line-height:1.2;letter-spacing:-.02em}
h3{font-size:20px;line-height:1.4;font-weight:800}
h1,h2,h3{text-wrap:balance;overflow-wrap:break-word}
code,kbd,pre{font-family:var(--font-mono)}
code{overflow-wrap:anywhere;font-size:.9em;background:var(--panel-2);border-radius:var(--radius-xs);padding:.12em .3em}
pre{max-width:100%;overflow-x:auto;padding:20px;border:1px solid var(--border);border-radius:var(--radius);background:var(--panel-2)}
pre code{padding:0;overflow-wrap:normal;white-space:pre}
.section{padding-top:80px;padding-bottom:80px}
.section-head{margin-bottom:32px}
.eyebrow{font-size:13px;font-weight:700;letter-spacing:.06em;color:var(--accent-dark)}
.sec-title{margin-top:12px;font-family:var(--font-display);font-weight:var(--weight-display);font-size:var(--size-section);line-height:1.15;letter-spacing:-.02em}
.lead{margin-top:16px;font-size:16px;line-height:1.75;color:var(--muted)}
.muted{color:var(--muted)}
.mono{font-family:var(--font-mono)}
.card,.panel{background:var(--panel);border:1px solid var(--border);border-radius:var(--radius-l);box-shadow:var(--shadow-card);padding:16px}
.panel{padding:24px;box-shadow:var(--hl-inner),0 20px 60px -28px var(--glow)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:52px;padding:12px 28px;border:1px solid var(--clear);border-radius:var(--radius-s);font-size:16px;font-weight:700;line-height:1.4;text-align:center;transition:background .2s,transform .2s,border-color .2s;flex-shrink:0;white-space:nowrap}
.btn-primary{background:var(--accent);color:var(--text);box-shadow:var(--shadow-btn)}
.btn-primary:hover,.btn-primary.is-hover{background:var(--accent-hover);transform:translateY(-1px)}
.btn-primary:active,.btn-primary.is-active{background:var(--accent);transform:translateY(1px)}
.btn-ghost,.btn-secondary{background:var(--panel);color:var(--text);border-color:var(--border-strong);font-weight:600}
.btn-ghost:hover,.btn-secondary:hover{border-color:var(--text)}
.btn:disabled,.btn[aria-disabled="true"]{background:var(--panel-2);border-color:var(--border);color:var(--muted);box-shadow:none;transform:none}
.btn-small{min-height:40px;padding:8px 16px;font-size:14px}
.cta-row{display:flex;flex-wrap:wrap;gap:14px;margin-top:26px}
.brand{display:inline-flex;align-items:center;gap:10px;font-family:var(--font-display);font-weight:900;font-size:21px;letter-spacing:-.03em;flex-shrink:0;white-space:nowrap}
.brand-mark{width:32px;height:32px;border-radius:var(--radius-logo);flex-shrink:0}
.brand-zh{font-size:16px;font-weight:500;color:var(--muted)}
.topbar{position:relative;z-index:50}
.topbar .wrap{display:flex;align-items:center;flex-wrap:nowrap;height:var(--header-height);gap:0}
.nav-desktop{flex:1;min-width:0;margin-left:60px}
.nav-links{display:flex;align-items:center;list-style:none;margin:0;padding:0;gap:30px;font-size:15px}
.nav-links li{flex-shrink:0}
.nav-links a{display:inline-flex;align-items:center;min-height:40px;color:var(--muted);font-weight:500;transition:color .2s}
.nav-links a:hover{color:var(--text)}
.nav-links a[aria-current="page"]{color:var(--text);font-weight:700}
.nav-end{margin-left:auto;display:flex;align-items:center;gap:22px;flex-shrink:0}
.lang-picker{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:40px;min-width:44px;width:auto;padding:6px 0;border:0;background:var(--clear);font-size:14px;font-weight:500;color:var(--text);white-space:nowrap}
.lang span{white-space:nowrap}
.lang svg{color:var(--muted)}
.lang-panel{position:absolute;right:0;top:calc(100% + 8px);z-index:80;min-width:172px;padding:8px;border:1px solid var(--border);border-radius:var(--radius);background:var(--panel);box-shadow:var(--shadow-card)}
.lang-panel a{display:flex;align-items:center;min-height:40px;padding:8px 12px;font-size:14px;border-radius:var(--radius-xs)}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--panel-2);color:var(--text)}
.login{display:inline-flex;align-items:center;justify-content:center;min-height:40px;padding:8px 24px;border-radius:var(--radius-pill);background:var(--accent);color:var(--text);font-weight:700;font-size:15px;box-shadow:var(--shadow-btn);transition:background .2s,transform .2s;white-space:nowrap}
.login:hover{background:var(--accent-hover);transform:translateY(-1px)}
.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(--radius-s);background:var(--panel);color:var(--text)}
.menu-line{display:block;width:20px;height:2px;background:currentColor;border-radius:var(--radius-pill)}
.nav-drawer{display:none;position:fixed;z-index:45;top:var(--header-height);left:0;right:0;height:calc(100dvh - var(--header-height));max-height:calc(100dvh - var(--header-height));padding:16px var(--gutter) 32px;background:var(--panel);overflow-y:auto;overscroll-behavior:contain}
.nav-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px 16px;border-radius:var(--radius-s);font-weight:600}
.nav-drawer a:hover,.nav-drawer a[aria-current="page"]{background:var(--panel-2)}
.drawer-languages{margin-top:16px;padding-top:16px;border-top:1px solid var(--border)}
.nav-veil{display:none;position:fixed;z-index:40;top:var(--header-height);bottom:0;left:0;right:0;border:0;background:var(--veil)}
.site-footer{margin-top:64px;padding-top:56px;padding-bottom:24px;border-top:1px solid var(--border);background:linear-gradient(180deg,var(--panel-2),var(--bg))}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr;gap:64px}
.footer-brand p{max-width:350px;margin-top:16px;color:var(--muted);font-size:14px}
.footer-heading{font-size:14px;font-weight:800;margin-bottom:14px}
.footer-links{display:grid;grid-template-columns:1fr 1fr;gap:4px 16px}
.footer-links a,.footer-languages a,.footer-legal a{display:inline-flex;align-items:center;min-height:32px;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 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:20px}
.prose{max-width:880px;line-height:1.85;overflow-wrap:break-word}
.prose p,.prose ul,.prose ol,.prose pre,.prose .callout,.prose table{margin-top:20px;margin-bottom:20px}
.prose h2{margin-top:48px;margin-bottom:20px;font-size:32px}
.prose h3{margin-top:32px;margin-bottom:16px}
.prose ul{list-style:disc;padding-left:1.4em}
.prose ol{padding-left:1.6em}
.prose a{color:var(--accent-dark);text-decoration:underline;text-underline-offset:3px}
.reveal{transition:opacity .35s var(--ease),transform .35s var(--ease)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{display:block;position:relative;min-width:0;width:100%;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:32px}
#server-status + *{margin-top:32px}
@media(max-width:1280px){
  .nav-desktop{margin-left:32px}
  .nav-links{gap:20px;font-size:14px}
  .nav-end{gap:16px}
  html:lang(en) .nav-links,html:lang(ja) .nav-links,html:lang(ko) .nav-links{gap:12px;font-size:12px}
}
@media(max-width:1100px){
  .nav-desktop{display:none}
  .nav-end{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .nav-drawer.is-open,.nav-veil.is-open{display:block}
  .footer-grid{gap:32px}
}
@media(max-width:768px){
  h1{font-size:clamp(28px,5.2vw,40px)}
  h2,.sec-title{font-size:30px}
  .section{padding-top:56px;padding-bottom:56px}
  .footer-grid{grid-template-columns:1fr 1fr}
  .footer-brand{grid-column:1 / -1}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .wrap{padding-inline:var(--gutter)}
  .brand{font-size:18px;gap:7px}
  .brand-mark{width:28px;height:28px}
  .brand-zh{font-size:13px}
  .nav-end{gap:8px;margin-left:auto}
  .login{font-size:14px;padding:8px 16px}
  .lang{font-size:12px;gap:4px}
  .lang svg{display:none}
  .menu-toggle{padding:8px}
  .footer-grid{grid-template-columns:1fr;gap:28px}
  .footer-brand{grid-column:auto}
  .footer-bottom{align-items:flex-start;flex-direction:column}
  .tilt{transform:none}
  .decoration{max-width:100%}
  .prose h2{font-size:27px}
  .btn{padding-inline:20px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation:none!important;transition:none!important}
  .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none}
}