:root{
  --bg:#E3EAF5;--bg-top:#EEF2FA;--panel:#F7FAFE;--panel-2:#D6E0EE;--side:#DCE4F0;--side-2:#E5EBF5;
  --border:#C6D2E3;--border-soft:#D7E0EC;--accent:#F28B1E;--accent-2:#E9771E;--accent-dark:#B85F06;
  --accent-22:rgba(242,139,30,.22);--accent-14:rgba(242,139,30,.14);--accent-10:rgba(242,139,30,.10);--accent-shadow:rgba(233,119,30,.30);
  --ink:#141A2A;--muted:#55617A;--faint:#8592A8;--success:#1E9A6A;--success-12:rgba(30,154,106,.13);--warn:#C98208;--warn-14:rgba(201,130,8,.15);--error:#D23F3F;
  --ice:#DCE9F8;--ice-line:#7EA8DA;--ice-ink:#2C5B92;--ice-ring:rgba(126,168,218,.22);--tape:rgba(160,192,232,.55);
  --note:#FFF5D6;--note-2:#FDEDBE;--note-shade:rgba(201,130,8,.16);--hi:rgba(255,255,255,.92);--hi-soft:rgba(255,255,255,.22);--hi-btn:rgba(255,255,255,.36);
  --on-accent:#FFFFFF;--shade-near:rgba(20,26,42,.07);--shade-mid:rgba(38,52,82,.10);--veil:rgba(20,26,42,.32);
  --glow-warm:rgba(242,139,30,.15);--glow-cool:rgba(126,169,224,.24);
  --tl-r:#EE6B60;--tl-y:#F3BD4E;--tl-g:#5DBE6A;--tl-edge:rgba(20,26,42,.12);
  --flag-red:#D9262C;--flag-white:#FFFFFF;--flag-blue:#2A3E7C;--flag-green:#1F8A4C;--flag-edge:rgba(20,26,42,.16);
  --band:#141A2A;--on-dark:#F7FAFE;--on-dark-muted:#9AA6BD;--clear:transparent;
  --r-check:4px;--r-xs:6px;--r-s:8px;--r-m:10px;--r-l:12px;--r-pill:999px;--r-round:50%;
  --f-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --f-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Malgun Gothic","Microsoft YaHei",system-ui,sans-serif;
  --f-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --text-xs:12px;--text-sm:14px;--text-base:16px;--text-lg:18px;--display-size:64px;--h2-size:36px;--h3-size:22px;
  --weight-normal:400;--weight-medium:500;--weight-semibold:600;--weight-bold:700;--weight-heavy:800;--weight-display:900;
  --wrap:1200px;--gutter:24px;--head-height:60px;--notice-height:34px;--drawer-top:94px;--anchor-space:96px;--toc-offset:12px;--toc-space:92px;
  --shadow-card:0 1px 2px var(--shade-near),0 14px 28px -14px var(--shade-mid),0 40px 90px -18px var(--accent-10);
  --ease: .2s ease;--reveal-time:.35s;
}
*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-space);scroll-behavior:smooth}
body{font-family:var(--f-body);font-size:var(--text-base);line-height:1.6;color:var(--ink);background:var(--bg);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
[hidden]{display:none!important}
img,svg{vertical-align:middle;max-width:100%}
img{height:auto}
svg{flex-shrink:0}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
a{color:inherit;text-underline-offset:3px}
button,a,summary{ -webkit-tap-highlight-color:var(--accent-14)}
:where(a,button,input,select,textarea,summary,[tabindex]):focus-visible{outline:2px solid var(--accent-dark);outline-offset:3px}
button:disabled,.btn[aria-disabled="true"]{cursor:not-allowed;opacity:.55}
button:disabled{transform:none}
ul{list-style:none}
h1,h2,h3{font-family:var(--f-display);letter-spacing:-.02em;text-wrap:balance;overflow-wrap:break-word}
h1{font-size:clamp(52px,5vw,var(--display-size));font-weight:var(--weight-display);line-height:1.1}
h2{font-size:var(--h2-size);font-weight:var(--weight-heavy);line-height:1.25}
h3{font-size:var(--h3-size);font-weight:var(--weight-bold);line-height:1.4}
p{overflow-wrap:break-word}
code{font-family:var(--f-mono);overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:20px;border-radius:var(--r-s);background:var(--panel-2)}
pre code{overflow-wrap:normal;white-space:pre}
table{border-collapse:collapse}
th,td{word-break:keep-all}
:where(main,section,article,nav,aside,div){min-width:0}
.wrap{width:100%;max-width:calc(var(--wrap) + var(--gutter)*2);margin-inline:auto;padding-inline:var(--gutter)}
.sec{padding-top:80px;padding-bottom:80px}
.no-break{white-space:nowrap}
.lat{letter-spacing:-.03em}
.muted{color:var(--muted)}
.mono{font-family:var(--f-mono);font-variant-numeric:tabular-nums}
.panel,.card{background:var(--panel);border:1px solid var(--border);border-radius:var(--r-l);box-shadow:var(--shadow-card),inset 0 1px 0 var(--hi);padding:28px}
.inset-panel{background:var(--panel-2);border-radius:var(--r-m);padding:20px;box-shadow:inset 0 1px 3px var(--shade-mid)}
.grid-3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.stack{display:grid;gap:20px}
.section-head{margin-bottom:32px}
.section-head p{margin-top:12px;max-width:760px;color:var(--muted)}
.prose{max-width:800px;line-height:1.85}
.prose p,.prose ul,.prose ol,.prose pre,.prose table{margin-block:20px}
.prose ul{list-style:disc;padding-left:24px}
.prose ol{padding-left:24px}
.prose h2{margin-top:48px;margin-bottom:20px}
.prose h3{margin-top:32px;margin-bottom:14px}
.prose a{color:var(--accent-dark)}
.prose section[id]{scroll-margin-top:var(--anchor-space)}
.decorated{position:relative;overflow-x:clip}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:10px 22px;border:0;border-radius:var(--r-pill);font-size:var(--text-base);font-weight:var(--weight-bold);text-decoration:none;line-height:1.4;flex-shrink:0;white-space:nowrap;transition:transform var(--ease),box-shadow var(--ease)}
.btn svg{width:16px;height:16px}
.btn-accent,.btn-primary{color:var(--on-accent);background:linear-gradient(180deg,var(--accent),var(--accent-2));box-shadow:inset 0 1px 0 var(--hi-btn),0 8px 18px -6px var(--accent-shadow)}
.btn-accent:hover,.btn-primary:hover{transform:translateY(-1px);box-shadow:inset 0 1px 0 var(--hi-btn),0 12px 22px -6px var(--accent-shadow)}
.btn-ghost,.btn-secondary{color:var(--ink);background:var(--panel);box-shadow:inset 0 0 0 1px var(--border),0 2px 6px -2px var(--shade-mid)}
.btn-ghost:hover,.btn-secondary:hover{transform:translateY(-1px)}
.btn:active{transform:translateY(1px)}
.btn-sm{min-height:38px;height:38px;padding:0 18px;font-size:var(--text-sm)}
.btn-lg{height:48px;padding:0 26px}
.notice{min-height:var(--notice-height);display:flex;align-items:center;justify-content:center;background:var(--bg-top);border-bottom:1px solid var(--border-soft);padding-inline:16px}
.notice a{display:inline-flex;align-items:center;gap:10px;min-height:var(--notice-height);font-size:13.5px;line-height:20px;text-decoration:none}
.notice-tag{font-size:var(--text-xs);font-weight:var(--weight-bold);line-height:20px;padding:0 9px;border-radius:var(--r-pill);color:var(--on-accent);background:linear-gradient(180deg,var(--accent),var(--accent-2));flex-shrink:0}
.notice-sep{color:var(--faint)}
.notice-arrow{display:inline-flex;color:var(--muted)}
#site-header{position:relative;z-index:50}
.site-head{position:relative;z-index:52;height:var(--head-height)}
.site-head>.wrap{display:flex;align-items:center;height:100%;gap:28px;flex-wrap:nowrap}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;flex-shrink:0}
.brand-mark{width:32px;height:32px;display:block;border-radius:var(--r-s);box-shadow:0 4px 10px -2px var(--accent-shadow)}
.brand-en{font-family:var(--f-display);font-weight:var(--weight-heavy);font-size:19px;letter-spacing:-.03em}
.brand-zh{font-size:var(--text-sm);font-weight:var(--weight-medium);color:var(--muted)}
.desktop-nav{flex:1;min-width:0}
.menu{display:flex;align-items:center;justify-content:center;list-style:none;margin:0;padding:0;gap:30px}
.menu a{display:inline-flex;align-items:center;min-height:32px;font-size:15px;font-weight:var(--weight-medium);color:var(--muted);text-decoration:none;white-space:nowrap}
.menu a:hover,.menu a[aria-current="page"]{color:var(--ink)}
.menu a[aria-current="page"]{font-weight:var(--weight-bold)}
.head-end{display:flex;align-items:center;gap:18px;flex-shrink:0}
.lang-box{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:4px;min-width:44px;min-height:38px;width:auto;font-size:var(--text-sm);font-weight:var(--weight-medium);color:var(--muted);background:var(--clear);border:0;white-space:nowrap}
.lang span{white-space:nowrap}
.lang-panel{position:absolute;z-index:65;right:0;top:calc(100% + 8px);width:180px;padding:8px;border-radius:var(--r-m);border:1px solid var(--border);background:var(--panel);box-shadow:var(--shadow-card)}
.lang-panel a{display:flex;align-items:center;min-height:40px;padding:8px 12px;text-decoration:none;border-radius:var(--r-xs)}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--panel-2)}
.menu-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;border:0;background:var(--clear);color:var(--ink);border-radius:var(--r-s)}
.menu-line{display:block;width:20px;height:2px;background:currentColor}
.drawer{position:fixed;z-index:51;top:var(--drawer-top);left:0;right:0;height:calc(100dvh - var(--drawer-top));max-height:calc(100dvh - var(--drawer-top));overflow-y:auto;overscroll-behavior:contain;background:var(--panel);padding:16px var(--gutter) 32px;border-top:1px solid var(--border)}
.drawer ul{display:block;list-style:none;margin:0;padding:0}
.drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px 16px;text-decoration:none;border-radius:var(--r-s)}
.drawer a:hover,.drawer a[aria-current="page"],.drawer a[aria-current="true"]{background:var(--panel-2);font-weight:var(--weight-bold)}
.drawer-languages{margin-top:16px;padding-top:16px;border-top:1px solid var(--border)}
.nav-veil{position:fixed;z-index:49;inset:var(--drawer-top) 0 0;background:var(--veil);border:0;width:100%;height:calc(100dvh - var(--drawer-top))}
html.nav-open{overflow:hidden}
.site-footer{background:var(--side-2);border-top:1px solid var(--border);padding-top:56px;padding-bottom:24px}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr;gap:48px}
.footer-brand p{max-width:330px;margin-top:16px;color:var(--muted);font-size:var(--text-sm)}
.footer-title{font-size:var(--text-sm);font-weight:var(--weight-bold);margin-bottom:12px}
.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px 16px}
.footer-links a,.footer-languages a,.footer-legal a{display:inline-flex;align-items:center;min-height:28px;font-size:13px;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 20px;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:12px;margin-top:20px;font-size:var(--text-xs);color:var(--muted)}
.footer-legal{display:flex;gap:20px}
.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}
#server-status{display:block;position:static;min-height:240px;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:32px}
#server-status+*{margin-top:32px}
@media(min-width:961px){.drawer,.nav-veil{display:none!important}}
@media(max-width:1150px){.menu{gap:18px}.site-head>.wrap{gap:20px}.head-end{gap:12px}}
@media(max-width:1080px){.brand-zh{display:none}.menu{gap:16px}.menu a{font-size:var(--text-sm)}}
@media(max-width:960px){.desktop-nav{display:none}.head-end{margin-left:auto}.menu-toggle{display:flex}.site-head>.wrap{gap:12px}.footer-grid{gap:24px}}
@media(max-width:768px){h1{font-size:38px}h2{font-size:28px}.grid-3{grid-template-columns:1fr}.sec{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}
  .tilt,[data-tilt],.float-note{transform:none}
  .decorated>*{max-width:100%}
  .site-head>.wrap{gap:8px}
  .brand{gap:6px}.brand-mark{width:27px;height:27px}.brand-en{font-size:17px}
  .head-end{gap:4px;margin-left:auto}
  .head-end .btn-sm{height:34px;min-height:34px;padding-inline:12px;font-size:var(--text-xs)}
  .lang{font-size:11px;gap:2px;min-height:34px}
  .notice a{font-size:11px;gap:6px}
  .notice-tag{font-size:10px;padding-inline:6px}
  .footer-grid{grid-template-columns:1fr}
  .footer-brand{grid-column:auto}
  .panel,.card{padding:20px}
  .footer-bottom{align-items:flex-start;flex-direction:column}
}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*::before,*::after{transition:none!important}.reveal,.reveal.pending{opacity:1;transform:none}}