:root {
  color-scheme: light;
  --bg:#E7ECF8;
  --bg-panel:#F7F9FE;
  --bg-panel-2:#DAE2F3;
  --border:#C9D3E8;
  --accent:#FF5B3A;
  --accent-dark:#D23E21;
  --text:#12141C;
  --text-muted:#5A6278;
  --text-faint:#8A92A8;
  --success:#1F9D6B;
  --warn:#C98A0A;
  --error:#D23B4A;
  --ink-2:#2A2E3B;
  --on-ink:#FFFFFF;
  --hero-top:#F0F3FB;
  --hero-bottom:#E2E8F6;
  --notice-bg:#DCD6F6;
  --accent-soft:rgba(255,91,58,.18);
  --accent-soft-2:rgba(255,128,96,.30);
  --glow-coral:rgba(255,91,58,.06);
  --glow-pink:rgba(255,150,184,.06);
  --shadow-tint:rgba(255,91,58,.10);
  --shadow-ink:rgba(18,20,28,.07);
  --shadow-ink-strong:rgba(18,20,28,.24);
  --edge-hi:rgba(255,255,255,.80);
  --sheen:rgba(255,255,255,.40);
  --sheen-soft:rgba(255,255,255,.12);
  --glass:rgba(255,255,255,.58);
  --glass-strong:rgba(255,255,255,.88);
  --hairline:rgba(18,20,28,.09);
  --lav-1:#EEEAFE;
  --lav-2:#CCC3F3;
  --lemon-1:#FFF9D8;
  --lemon-2:#F4E07A;
  --mint-1:#E3F8EE;
  --mint-2:#A6E1C4;
  --porc-1:#FFFFFF;
  --porc-2:#EDF1FA;
  --pointer:#2F6BFF;
  --pointer-soft:rgba(47,107,255,.12);
  --flag-red:#D7323C;
  --flag-white:#FFFFFF;
  --flag-blue:#253A7A;
  --flag-green:#1C8A4E;
  --veil:rgba(18,20,28,.24);
  --clear:transparent;
  --r-s:8px;
  --r-m:10px;
  --r-l:12px;
  --r-mini:6px;
  --r-tag:5px;
  --r-flag:3px;
  --r-dot:1px;
  --r-round:50%;
  --r-pill: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,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --gutter:32px;
  --content-width:1344px;
  --reading-width:800px;
  --header-height:112px;
  --anchor-offset:128px;
  --toc-offset:184px;
  --space-section:88px;
  --ease-out:cubic-bezier(.2,.7,.2,1);
  --time-ui:.2s;
  --time-reveal:.35s;
  --shadow-panel:inset 0 0 0 1px var(--edge-hi),0 20px 48px -24px var(--shadow-tint);
  --shadow-card:inset 0 0 0 1px var(--edge-hi),0 2px 6px var(--shadow-ink),0 34px 64px -18px var(--shadow-tint),0 18px 40px -24px var(--shadow-ink-strong);
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-offset);scroll-behavior:smooth}
html.nav-open{overflow:hidden}
body{margin:0;font-family:var(--font-body);color:var(--text);background:var(--bg);line-height:1.5;-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}
button{border:0}
img{display:block;max-width:100%;height:auto}
svg{flex-shrink:0}
ul{margin:0;padding:0;list-style:none}
p{margin:0}
h1,h2,h3,h4{font-family:var(--font-display);margin:0;overflow-wrap:break-word;text-wrap:balance}
h1{font-size:clamp(52px,5vw,68px);font-weight:800;line-height:1.1;letter-spacing:-.02em}
h2{font-size:clamp(28px,3vw,40px);font-weight:400;line-height:1.25}
h3{font-size:22px;font-weight:500;line-height:1.4}
[hidden]{display:none!important}
:where(a,button,input,select,textarea,summary,[tabindex]):focus-visible{outline:2px solid var(--accent);outline-offset:3px}
:where(button,summary){min-height:24px}
.wrap{width:100%;max-width:var(--content-width);padding-inline:var(--gutter);margin-inline:auto}
.reading-wrap{width:100%;max-width:var(--reading-width);padding-inline:var(--gutter);margin-inline:auto}
.sec{padding-top:var(--space-section);padding-bottom:var(--space-section)}
.no-break{white-space:nowrap}
.vh{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.muted{color:var(--text-muted)}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums}
.subtitle{margin-top:16px;color:var(--text-muted);font-size:18px;line-height:1.7}
.grid-two,.grid-three{display:grid;gap:24px}
.grid-two{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-three{grid-template-columns:repeat(3,minmax(0,1fr))}
:where(.grid-two,.grid-three,.hero-grid,.footer-grid)>*{min-width:0}
.panel{padding:28px;border-radius:var(--r-l);background:var(--bg-panel);box-shadow:var(--shadow-panel)}
.inset-panel{padding:24px;border-radius:var(--r-m);background:var(--bg-panel-2)}
.decor-section{position:relative;overflow-x:clip;max-width:100%}
.prose{font-size:16px;line-height:1.9;overflow-wrap:break-word;min-width:0}
.prose p,.prose ul,.prose ol,.prose blockquote,.prose pre{margin-block:20px}
.prose h2{margin-top:48px;margin-bottom:20px}
.prose h3{margin-top:32px;margin-bottom:12px}
.prose ul{list-style:disc;padding-left:24px}
.prose ol{padding-left:28px}
.prose li+li{margin-top:8px}
.prose a,.text-link{text-decoration:underline;text-underline-offset:4px;text-decoration-thickness:1px}
.text-link{display:inline-flex;align-items:center;gap:8px;min-height:32px;font-weight:500}
code{font-family:var(--font-mono);font-size:.9em;overflow-wrap:anywhere}
:not(pre)>code{background:var(--bg-panel-2);padding:2px 5px;border-radius:var(--r-tag)}
pre{max-width:100%;overflow-x:auto;padding:24px;border-radius:var(--r-m);background:var(--bg-panel-2)}
pre code{overflow-wrap:normal;white-space:pre}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:54px;padding:12px 28px;border:0;border-radius:var(--r-m);font-size:16px;font-weight:600;letter-spacing:.01em;flex-shrink:0;white-space:nowrap;transition:background-color var(--time-ui),box-shadow var(--time-ui)}
.btn svg{width:18px;height:18px;display:block;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.btn-solid,.btn-primary{background:var(--text);color:var(--on-ink);box-shadow:inset 0 1px 0 var(--sheen-soft),0 14px 28px -14px var(--shadow-ink-strong)}
.btn-solid:hover,.btn-primary:hover{background:var(--ink-2)}
.btn-line,.btn-secondary{background:var(--glass);color:var(--text);box-shadow:inset 0 0 0 1.5px var(--text)}
.btn-line:hover,.btn-secondary:hover{background:var(--bg-panel)}
.btn:active{box-shadow:inset 0 0 0 2px var(--text-muted)}
.btn:disabled,.btn[aria-disabled="true"]{background:var(--bg-panel-2);color:var(--text-muted);box-shadow:none}
.btn-small{min-height:40px;padding:8px 18px;font-size:14px}
#site-header,.site-header{position:sticky;top:0;z-index:100}
.notice{background:var(--notice-bg);color:var(--text)}
.notice-in{display:flex;align-items:center;gap:14px;height:44px}
.notice-mark{display:inline-flex;width:22px;height:22px;flex:none}
.notice-mark svg{width:22px;height:22px;display:block}
.g-disc{fill:var(--text)}
.g-line{fill:none;stroke:var(--notice-bg);stroke-width:1.3}
.notice-text{font-size:14px;font-weight:500;letter-spacing:.01em}
.notice-text b{font-weight:700}
.notice-text .sep{margin:0 10px;color:var(--text-muted)}
.notice-btn{margin-left:auto;display:inline-flex;align-items:center;justify-content:center;min-height:30px;padding:4px 16px;border-radius:var(--r-s);background:var(--text);color:var(--on-ink);font-size:13px;font-weight:600;white-space:nowrap;flex-shrink:0}
.notice-btn:hover{background:var(--ink-2)}
.topbar{position:relative;background:var(--hero-top);border-bottom:1px solid var(--hairline);z-index:103}
.topbar-in{display:flex;align-items:center;flex-wrap:nowrap;height:68px;gap:28px}
.brand{display:inline-flex;align-items:center;gap:10px;flex:none;min-height:32px}
.brand img{width:32px;height:32px;flex-shrink:0}
.brand-en{font-family:var(--font-display);font-weight:800;font-size:18px;letter-spacing:-.02em}
.brand-zh{font-size:14px;font-weight:400;color:var(--text-muted)}
.mainnav{flex:1;min-width:0}
.mainnav ul{display:flex;align-items:center;list-style:none;margin:0;padding:0;gap:2px}
.mainnav a{display:inline-flex;align-items:center;gap:6px;min-height:36px;padding:6px 10px;border-radius:var(--r-s);font-size:14px;font-weight:500;color:var(--text-muted);white-space:nowrap}
.nav-icon{width:16px;height:16px;display:block;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
.mainnav a:hover{color:var(--text);background:var(--glass)}
.mainnav a[aria-current="page"]{color:var(--text);background:var(--bg-panel);box-shadow:inset 0 0 0 1px var(--border)}
.topbar-tools{margin-left:auto;display:flex;align-items:center;gap:10px;flex-shrink:0}
.lang-box{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;min-height:36px;padding:6px 10px;border:0;background:var(--clear);border-radius:var(--r-s);font-size:14px;color:var(--text-muted);cursor:pointer}
.lang span{white-space:nowrap}
.lang svg{width:16px;height:16px;display:block;fill:none;stroke:currentColor;stroke-width:1.6}
.lang:hover{color:var(--text);background:var(--glass)}
.lang-panel{position:absolute;right:0;top:calc(100% + 10px);z-index:120;min-width:180px;padding:8px;border-radius:var(--r-m);background:var(--bg-panel);border:1px solid var(--border);box-shadow:var(--shadow-panel)}
.lang-panel a{display:flex;align-items:center;min-height:44px;width:100%;padding:10px 12px;border-radius:var(--r-s);font-size:14px}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--bg-panel-2)}
.btn-login{display:inline-flex;align-items:center;justify-content:center;min-height:38px;padding:8px 20px;border-radius:var(--r-s);background:var(--text);color:var(--on-ink);font-size:14px;font-weight:600;white-space:nowrap;box-shadow:0 8px 18px -10px var(--shadow-ink-strong)}
.btn-login:hover{background:var(--ink-2)}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;padding:10px;border-radius:var(--r-s);background:var(--clear);color:var(--text)}
.menu-toggle svg{display:block;width:22px;height:22px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round}
.nav-drawer{display:none;position:fixed;top:var(--header-height);right:0;left:0;height:calc(100dvh - var(--header-height));max-height:calc(100dvh - var(--header-height));overflow-y:auto;overscroll-behavior:contain;background:var(--bg-panel);padding:16px var(--gutter) 32px;z-index:102}
.nav-drawer a{display:flex;align-items:center;gap:12px;width:100%;min-height:48px;padding:12px 14px;border-radius:var(--r-s)}
.nav-drawer a:hover,.nav-drawer a[aria-current="page"]{background:var(--bg-panel-2)}
.drawer-languages{border-top:1px solid var(--border);margin-top:16px;padding-top:12px}
.drawer-languages a[aria-current="true"]{font-weight:700;background:var(--bg)}
.nav-veil{display:none;position:fixed;inset:var(--header-height) 0 0;background:var(--veil);z-index:101}
.site-footer{background:var(--bg-panel-2);border-top:1px solid var(--border);padding-top:56px;padding-bottom:28px}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr 1fr;gap:36px}
.footer-brand p{max-width:30em;margin-top:18px;color:var(--text-muted);font-size:14px;line-height:1.8}
.footer-title{font-size:15px;font-weight:600;margin-bottom:12px}
.footer-links{display:grid;gap:4px}
.footer-links a{display:inline-flex;align-items:center;min-height:32px;font-size:14px;color:var(--text-muted)}
.footer-links a:hover{text-decoration:underline;color:var(--text)}
.footer-bottom{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:16px;margin-top:40px;padding-top:24px;border-top:1px solid var(--border);font-size:13px;color:var(--text-muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:16px}
.footer-legal a{display:inline-flex;align-items:center;min-height:28px}
.reveal{transition:opacity var(--time-reveal) var(--ease-out),transform var(--time-reveal) var(--ease-out)}
.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%;overflow:hidden;margin-block:24px}
#server-status+*{margin-top:24px}
@media(min-width:1121px) and (max-width:1390px){
  .topbar-in{gap:16px}
  .mainnav a{padding-inline:7px;font-size:13px;gap:4px}
  .topbar-tools{gap:4px}
  .lang{padding-inline:6px}
}
@media(max-width:1120px){
  .mainnav{display:none}
  .menu-toggle{display:inline-flex}
  .topbar-tools{margin-left:auto}
  .nav-drawer:not([hidden]),.nav-veil:not([hidden]){display:block}
}
@media(min-width:1121px){
  .nav-drawer,.nav-veil{display:none!important}
}
@media(max-width:980px){
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:768px){
  h1{font-size:40px}
  .grid-three{grid-template-columns:minmax(0,1fr)}
  :root{--space-section:56px}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .wrap,.reading-wrap{width:100%;padding-inline:var(--gutter)}
  .notice-in{gap:8px}
  .notice-text{font-size:12px}
  .notice-text .sep,.notice-text .n-2{display:none}
  .notice-btn{font-size:12px;padding-inline:12px}
  .topbar-in{gap:8px}
  .brand{gap:7px}
  .brand-en{font-size:16px}
  .brand-zh{display:none}
  .brand img{width:28px;height:28px}
  .topbar-tools{gap:3px;margin-left:auto}
  .lang{padding-inline:6px}
  .lang span{display:none}
  .btn-login{padding-inline:13px;font-size:13px}
  .grid-two,.footer-grid{grid-template-columns:minmax(0,1fr)}
  .panel{padding:22px}
  .btn{min-height:50px;padding-inline:22px}
  .tilt,.content-tilt{transform:none}
  .decor-section{max-width:100%;overflow-x:clip}
  .footer-grid{gap:28px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition:none!important;animation:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}