:root {
  color-scheme:light;
  --bg:#F7F7F9;
  --panel:#FFFFFF;
  --panel-2:#EEEFF4;
  --border:#DFE1EA;
  --accent:#08806F;
  --accent-dark:#06614F;
  --text:#22232E;
  --muted:#5C6074;
  --success:#1E9E5A;
  --warn:#C9800E;
  --error:#D23C4B;
  --peri:#6C7BE8;
  --peri-soft:#8E9AF0;
  --peri-deep:#4F5FD0;
  --peri-top:#F3F4FF;
  --peri-mist:#AEB8F3;
  --peri-mist-lite:#D3D8F8;
  --peri-wash:#E1E0F8;
  --coral:#F4A6BF;
  --coral-lite:#F9CEDC;
  --mint:#9FE3D6;
  --mint-lite:#CDF1EA;
  --fog-blue:#DCE8FB;
  --fog-pink:#F9DDE6;
  --accent-wash:rgba(8,128,111,.08);
  --accent-tint:rgba(8,128,111,.16);
  --accent-glow:rgba(8,128,111,.34);
  --shadow-tint:rgba(8,128,111,.12);
  --peri-halo:rgba(108,123,232,.18);
  --peri-shadow:rgba(79,95,208,.30);
  --glass:rgba(255,255,255,.78);
  --glass-strong:rgba(255,255,255,.92);
  --highlight:rgba(255,255,255,.95);
  --hairline:rgba(223,225,234,.85);
  --slot:rgba(255,255,255,.22);
  --dot-edge:rgba(34,35,46,.14);
  --btn-sheen:rgba(255,255,255,.18);
  --veil:rgba(34,35,46,.24);
  --clear:transparent;
  --flag-red:#CF3442;
  --flag-blue:#27408F;
  --flag-white:#FFFFFF;
  --flag-edge:rgba(34,35,46,.14);
  --font-display:Georgia,'Noto Serif SC','Source Han Serif SC','Songti SC','Noto Sans SC','PingFang SC','Microsoft YaHei',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:6px;
  --r-md:8px;
  --r-lg:12px;
  --r-pill:999px;
  --edge-panel:inset 0 1px 0 var(--highlight),0 0 0 1px var(--hairline);
  --shadow-panel:0 24px 56px -22px var(--shadow-tint),0 4px 14px -6px var(--shadow-tint);
  --shadow-chip:0 14px 32px -14px var(--shadow-tint),0 2px 6px -2px var(--shadow-tint);
  --gutter:56px;
  --wrap-max:1424px;
  --header-h:72px;
  --anchor-gap:88px;
  --toc-offset:144px;
  --text-base:16px;
  --text-small:14px;
  --text-lede:18px;
  --title-size:clamp(52px,4.59vw,66px);
  --heading-size:clamp(28px,3vw,40px);
  --speed-fast:.2s;
  --speed-reveal:.35s;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:var(--anchor-gap)}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font-body);font-size:var(--text-base);line-height:1.6;-webkit-font-smoothing:antialiased}
html.nav-open{overflow:hidden}
[hidden]{display:none!important}
a{color:inherit;text-underline-offset:.2em}
button,input,select,textarea{font:inherit}
button{cursor:pointer}
button,a,input,summary{ -webkit-tap-highlight-color:var(--accent-tint)}
button{color:inherit}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:var(--r-xs)}
img{max-width:100%;height:auto}
svg{vertical-align:middle}
h1,h2,h3{font-weight:700;line-height:1.2;overflow-wrap:break-word}
h1{font-family:var(--font-display);font-size:var(--title-size);line-height:1.12;letter-spacing:-.02em}
h2{font-family:var(--font-display);font-size:var(--heading-size);letter-spacing:-.02em}
h3{font-size:20px}
p{margin:0 0 24px}
code{font-family:var(--font-mono);overflow-wrap:anywhere;font-size:.9em;background:var(--panel-2);border-radius:var(--r-xs);padding:2px 5px}
pre{max-width:100%;overflow-x:auto;background:var(--panel-2);border-radius:var(--r-md);padding:24px}
pre code{padding:0;white-space:pre;overflow-wrap:normal}
hr{border:0;border-top:1px solid var(--border);margin-block:32px}
.wrap{width:100%;max-width:var(--wrap-max);padding-inline:var(--gutter);margin-inline:auto}
.wrap > *,[class*="grid"] > *{min-width:0}
.section{padding-top:64px;padding-bottom:64px}
.section-head{display:flex;align-items:flex-end;justify-content:space-between;gap:24px;margin-bottom:32px}
.section-head h2{margin:8px 0 0}
.section-head p{margin:0}
.reading-wrap{max-width:880px;margin-inline:auto}
.prose{overflow-wrap:break-word;min-width:0}
.prose h2{margin:56px 0 24px}
.prose h3{margin:32px 0 16px}
.prose li{margin-block:8px}
.prose a:not(.btn){color:var(--accent-dark)}
.muted{color:var(--muted)}
.mono{font-family:var(--font-mono)}
.no-break{white-space:nowrap}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.svg-defs{position:absolute;width:0;height:0;overflow:hidden}
.skip{position:absolute;left:16px;top:-48px;z-index:100;padding:8px 16px;background:var(--panel);border-radius:var(--r-md);box-shadow:var(--shadow-chip);text-decoration:none;font-weight:600}
.skip:focus{top:16px}
.panel,.card{background:var(--panel);border-radius:var(--r-lg);box-shadow:var(--shadow-panel),var(--edge-panel);padding:32px;min-width:0}
.card h3{margin-top:0}
.kicker{margin:0;font-size:13px;font-weight:600;color:var(--accent-dark);letter-spacing:.04em}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:52px;padding:12px 26px;border:0;border-radius:var(--r-md);font-family:var(--font-body);font-size:16px;font-weight:600;text-decoration:none;line-height:1.5;transition:transform var(--speed-fast),background var(--speed-fast);max-width:100%}
.btn svg{width:18px;height:18px;flex-shrink:0}
.btn .ar{fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.btn-primary{background:var(--accent);color:var(--panel);box-shadow:0 12px 26px -12px var(--accent-glow),inset 0 1px 0 var(--btn-sheen)}
.btn-primary:hover,.btn-primary.is-hover{background:var(--accent-dark);transform:translateY(-1px)}
.btn-ghost,.btn-secondary{background:var(--panel);color:var(--text);box-shadow:var(--edge-panel),0 8px 18px -12px var(--shadow-tint)}
.btn-ghost:hover,.btn-secondary:hover{background:var(--panel-2);transform:translateY(-1px)}
.btn:active{transform:translateY(1px)}
.btn:disabled,.btn[aria-disabled="true"]{opacity:.5;cursor:not-allowed;transform:none}
.btn-small{min-height:44px;padding:8px 18px;font-size:14px}
.cta-row{display:flex;flex-wrap:wrap;gap:12px;margin-top:32px}
.site-header,#site-header{position:sticky;top:0;z-index:50}
.header-surface{position:relative;z-index:53;background:var(--glass);-webkit-backdrop-filter:saturate(1.4) blur(14px);backdrop-filter:saturate(1.4) blur(14px);box-shadow:0 1px 0 var(--border)}
.nav-bar{display:flex;align-items:center;height:var(--header-h);gap:0;flex-wrap:nowrap}
.brand{display:flex;align-items:center;gap:12px;text-decoration:none;flex-shrink:0}
.brand-mark{width:34px;height:34px;display:block}
.brand-en{font-weight:700;font-size:19px;letter-spacing:.03em;color:var(--text)}
.brand-zh{font-size:14px;font-weight:500;color:var(--muted);padding-left:12px;box-shadow:inset 1px 0 0 var(--border)}
.desktop-nav{flex:1;min-width:0;margin-left:48px;align-self:stretch}
.tabs{display:flex;align-items:center;list-style:none;margin:0;padding:0;gap:4px;height:100%}
.tabs li{display:flex;align-self:stretch}
.tabs a{position:relative;display:flex;align-items:center;padding:0 16px;font-size:15px;font-weight:500;color:var(--muted);text-decoration:none;white-space:nowrap}
.tabs a::after{content:"";position:absolute;left:16px;right:16px;bottom:0;height:3px;border-radius:var(--r-xs) var(--r-xs) 0 0;background:var(--accent);transform:scaleX(0);opacity:0;transition:transform .25s,opacity .25s}
.tabs a:hover{color:var(--text)}
.tabs a:hover::after{transform:scaleX(.42);opacity:.4}
.tabs a[aria-current="page"]{color:var(--text);font-weight:600}
.tabs a[aria-current="page"]::after{transform:scaleX(1);opacity:1}
.nav-end{margin-left:auto;display:flex;align-items:center;gap:12px;flex-shrink:0}
.lang{position:relative}
.lang-button{display:inline-flex;align-items:center;justify-content:center;gap:8px;width:auto;min-width:44px;min-height:44px;padding:8px 12px;border:0;border-radius:var(--r-md);background:var(--clear);font-size:14px;color:var(--muted)}
.lang-button span{white-space:nowrap}
.lang-button:hover{color:var(--text);background:var(--panel-2)}
.lang-button svg{width:16px;height:16px;flex-shrink:0;fill:none;stroke:currentColor;stroke-width:1.4}
.lang-menu{position:absolute;right:0;top:calc(100% + 8px);z-index:60;min-width:160px;margin:0;padding:6px;list-style:none;background:var(--panel);border-radius:var(--r-lg);box-shadow:var(--shadow-panel),var(--edge-panel)}
.lang-menu a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-sm);font-size:14px;text-decoration:none;color:var(--text)}
.lang-menu a:hover{background:var(--panel-2)}
.lang-menu a[aria-current="true"]{color:var(--accent-dark);font-weight:600}
.btn-login{display:inline-flex;align-items:center;justify-content:center;min-height:40px;padding:8px 20px;border-radius:var(--r-md);background:var(--accent-wash);box-shadow:inset 0 0 0 1px var(--accent-tint);color:var(--accent-dark);font-weight:600;font-size:14.5px;text-decoration:none;white-space:nowrap;transition:transform var(--speed-fast)}
.btn-login:hover{background:var(--accent-tint);transform:translateY(-1px)}
.menu-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:5px;min-width:44px;min-height:44px;border:0;border-radius:var(--r-md);background:var(--clear);color:var(--text)}
.menu-stroke{display:block;width:20px;height:2px;background:currentColor;border-radius:var(--r-xs)}
.nav-drawer{position:fixed;z-index:52;left:0;right:0;top:var(--header-h);height:calc(100dvh - var(--header-h));max-height:calc(100dvh - var(--header-h));overflow-y:auto;overscroll-behavior:contain;background:var(--panel);padding:24px var(--gutter)}
.nav-drawer a{display:flex;align-items:center;width:100%;min-height:48px;padding:12px 16px;text-decoration:none;border-radius:var(--r-md)}
.nav-drawer a:hover,.nav-drawer a[aria-current="page"]{background:var(--accent-wash);color:var(--accent-dark)}
.drawer-languages{border-top:1px solid var(--border);margin-top:16px;padding-top:16px}
.nav-veil{position:fixed;z-index:51;inset:var(--header-h) 0 0;background:var(--veil);border:0}
.site-footer{margin-top:64px;background:var(--panel);border-top:1px solid var(--border);padding-top:56px;padding-bottom:24px}
.footer-grid{display:grid;grid-template-columns:1.1fr 1fr 1.1fr;gap:56px}
.footer-brand p{margin-top:24px;max-width:28em;color:var(--muted);font-size:14px}
.footer-title{font-size:14px;font-weight:600;margin:0 0 16px}
.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 20px}
.footer-links a,.footer-languages a,.footer-legal a{display:inline-flex;align-items:center;min-height:32px;font-size:14px;text-decoration:none;color:var(--muted)}
.footer-links a:hover,.footer-languages a:hover,.footer-legal a:hover{color:var(--accent-dark)}
.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;flex-wrap:wrap;justify-content:space-between;gap:12px;margin-top:24px;font-size:13px;color:var(--muted)}
.footer-legal{display:flex;gap:20px;flex-wrap:wrap}
.reveal{transition:opacity var(--speed-reveal) ease,transform var(--speed-reveal) ease}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:relative;display:block;min-height:48px;width:100%;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:24px}
#server-status > *{min-width:0;max-width:100%}
#server-status + *{margin-top:24px}
@media(min-width:1001px) and (max-width:1270px){
  .desktop-nav{margin-left:24px}
  .tabs{gap:6px}
  .tabs a{padding-inline:9px;font-size:14px}
  .tabs a::after{left:9px;right:9px}
  .nav-end{gap:6px}
}
@media(max-width:1000px){
  :root{--gutter:32px}
  .desktop-nav{display:none}
  .menu-toggle{display:inline-flex}
  .nav-end{margin-left:auto}
  .footer-grid{gap:32px}
}
@media(max-width:768px){
  :root{--gutter:24px;--title-size:clamp(28px,7.4vw,40px)}
  .section{padding-top:40px;padding-bottom:40px}
  .section-head{align-items:flex-start;flex-direction:column;gap:16px}
  .footer-grid{grid-template-columns:1fr 1fr}
  .footer-brand{grid-column:1/-1}
}
@media(max-width:640px){
  :root{--gutter:16px;--header-h:64px;--anchor-gap:80px;--toc-offset:136px}
  .no-break{white-space:normal}
  .tilt,[data-tilt]{transform:none}
  .brand{gap:8px}
  .brand-en{font-size:16px}
  .brand-mark{width:28px;height:28px}
  .brand-zh{font-size:12px;padding-left:8px}
  .nav-end{gap:2px;margin-left:auto}
  .btn-login{padding:8px 12px;min-height:40px;font-size:13px}
  .lang-button{gap:4px;padding:8px 6px;font-size:12px}
  .lang-button svg{width:14px;height:14px}
  .menu-toggle{min-width:40px}
  .panel,.card{padding:24px}
  .footer-grid{grid-template-columns:1fr;gap:32px}
  .footer-brand{grid-column:auto}
  .btn{padding-inline:20px}
  .section-head h2{margin-top:8px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation:none!important;transition:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}