:root{
  --bg:#F5EDE0;
  --bg-top:#FAF4EA;
  --bg-bottom:#F1E7D6;
  --panel:#FFFBF4;
  --panel-2:#EDE3D3;
  --notice:#F3E3CF;
  --border:#DFD2BE;
  --border-strong:#C9B8A0;
  --line-soft:rgba(223,210,190,.75);
  --accent:#9B3324;
  --accent-2:#B4492F;
  --accent-dark:#73241A;
  --text:#2A211A;
  --ink-2:#3B2F25;
  --muted:#6E6152;
  --link:#2F55B0;
  --success:#2F7A4B;
  --warn:#B7791F;
  --error:#B42318;
  --on-accent:#FFFFFF;
  --clear:transparent;
  --accent-10:rgba(155,51,36,.10);
  --accent-12:rgba(155,51,36,.12);
  --accent-dark-18:rgba(115,36,26,.18);
  --accent-dark-30:rgba(115,36,26,.30);
  --ink-12:rgba(42,33,26,.12);
  --ink-35:rgba(42,33,26,.35);
  --veil:rgba(42,33,26,.35);
  --success-ring:rgba(47,122,75,.18);
  --glow:rgba(214,132,90,.16);
  --glow-soft:rgba(226,170,128,.08);
  --w-08:rgba(255,255,255,.08);
  --w-10:rgba(255,255,255,.10);
  --w-14:rgba(255,255,255,.14);
  --w-18:rgba(255,255,255,.18);
  --w-22:rgba(255,255,255,.22);
  --w-35:rgba(255,255,255,.35);
  --w-60:rgba(255,255,255,.60);
  --w-72:rgba(255,255,255,.72);
  --w-88:rgba(255,255,255,.88);
  --flag-red:#C23B2E;
  --flag-white:#FFFBF4;
  --flag-blue:#2C4A8F;
  --flag-green:#2F8452;
  --flag-ring:rgba(42,33,26,.16);
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Microsoft YaHei","Apple SD Gothic Neo","Malgun Gothic",system-ui,sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Microsoft YaHei","Apple SD Gothic Neo","Malgun Gothic",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --r-xs:6px;
  --r-sm:8px;
  --r-md:12px;
  --r-card:14px;
  --r-lg:24px;
  --r-pill:999px;
  --gutter:24px;
  --content-width:1248px;
  --header-height:64px;
  --anchor-offset:80px;
  --toc-offset:144px;
  --drawer-top:104px;
  --shadow-panel:0 20px 56px -24px var(--accent-10);
  --ease: cubic-bezier(.2,.65,.3,1);
  --fast: .2s;
  --reveal-time:.35s;
  --grain-opacity:.03;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:var(--anchor-offset)}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font-body);font-size:16px;line-height:1.5;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
body::before{content:"";position:fixed;inset:0;z-index:60;pointer-events:none;opacity:var(--grain-opacity);mix-blend-mode:multiply;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='paper'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.82' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Cpath filter='url(%23paper)' d='M0 0h160v160H0z'/%3E%3C/svg%3E")}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button,summary{cursor:pointer}
button{border:0;background:var(--clear)}
button:disabled,.btn[aria-disabled="true"]{cursor:not-allowed;opacity:.55;pointer-events:none}
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(--link);outline-offset:3px}
img,svg{vertical-align:middle}
img{max-width:100%;height:auto}
svg{flex-shrink:0}
ul,ol{padding-left:1.5em}
h1,h2,h3,h4,p{margin:0}
h1,h2,h3{font-family:var(--font-display);font-weight:400;overflow-wrap:break-word;text-wrap:balance}
h1{font-size:clamp(52px,4.6vw,68px);line-height:1.1;letter-spacing:-.02em}
h2{font-size:clamp(28px,3vw,40px);line-height:1.2;letter-spacing:-.02em}
h3{font-size:22px;line-height:1.35;letter-spacing:-.01em}
p{overflow-wrap:break-word}
code,kbd,pre{font-family:var(--font-mono)}
code{overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:20px;background:var(--panel-2);border-radius:var(--r-sm);line-height:1.7}
pre code{overflow-wrap:normal;white-space:pre}
table{border-collapse:collapse}
th,td{word-break:keep-all}
[hidden]{display:none!important}
.wrap{width:100%;max-width:var(--content-width);margin-inline:auto;padding-inline:var(--gutter)}
.sec{padding-top:72px;padding-bottom:72px}
.sec--compact{padding-top:40px;padding-bottom:40px}
.flow>*+*{margin-top:20px}
.grid{display:grid;gap:24px}
.grid>*{min-width:0}
.grid--three{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--five{grid-template-columns:repeat(5,minmax(0,1fr))}
.muted{color:var(--muted)}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums}
.text-link{display:inline-flex;align-items:center;gap:6px;min-height:24px;color:var(--link)}
.text-link:hover{text-decoration:underline;text-underline-offset:3px}
.no-break{white-space:nowrap}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip-path:inset(50%);white-space:nowrap;border:0}
.panel,.card{min-width:0;padding:28px;border:1px solid var(--border);border-radius:var(--r-lg);background:var(--panel);box-shadow:var(--shadow-panel)}
.panel--recess{background:var(--panel-2);box-shadow:none}
.prose{min-width:0;line-height:1.85}
.prose p,.prose ul,.prose ol{margin-top:18px;margin-bottom:18px}
.prose h2{margin-top:48px;margin-bottom:20px}
.prose h3{margin-top:30px;margin-bottom:14px}
.prose a:not(.btn){color:var(--link);text-decoration:underline;text-underline-offset:3px}
.prose img{border-radius:var(--r-md)}
.section-head{margin-bottom:32px}
.section-head p{max-width:760px;margin-top:14px;color:var(--muted);font-size:18px}
.icon{width:20px;height:20px}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.fr{fill:var(--flag-red)}
.fw{fill:var(--flag-white)}
.fb{fill:var(--flag-blue)}
.fg{fill:var(--flag-green)}
.fl-ring{fill:none;stroke:var(--flag-ring);stroke-width:.9}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:48px;padding:0 26px;border-radius:var(--r-sm);font-size:16px;font-weight:500;letter-spacing:.01em;flex-shrink:0;white-space:nowrap;transition:transform var(--fast) var(--ease),background-color var(--fast),box-shadow var(--fast)}
.btn svg{width:16px;height:16px;flex:none}
.btn:hover{transform:translateY(-1px)}
.btn--solid,.btn-primary{background:var(--text);color:var(--panel);box-shadow:inset 0 1px 0 var(--w-14),0 14px 28px -14px var(--ink-35)}
.btn--solid:hover,.btn-primary:hover{background:var(--ink-2)}
.btn--line,.btn-secondary{background:var(--panel);color:var(--text);box-shadow:inset 0 0 0 1.5px var(--text)}
.btn--line:hover,.btn-secondary:hover{box-shadow:inset 0 0 0 1.5px var(--text),0 10px 22px -14px var(--accent-12)}
.btn:active{transform:translateY(0);box-shadow:inset 0 0 0 2px var(--ink-12)}
.btn--small{height:40px;padding-inline:18px;font-size:14px}
.btn-chalk{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:40px;padding:0 18px;flex:none;border-radius:var(--r-sm);background:var(--panel);color:var(--text);font-size:14.5px;font-weight:500;box-shadow:0 10px 22px -12px var(--accent-dark-30);transition:transform var(--fast)}
.btn-chalk svg{width:14px;height:14px}
.btn-chalk:hover{transform:translateY(-1px)}
.notice{position:relative;z-index:5;display:flex;align-items:center;justify-content:center;gap:12px;min-height:40px;padding:7px 64px;background:var(--notice);border-bottom:1px solid var(--line-soft);font-size:14px;color:var(--text)}
.notice__text{color:var(--text)}
.notice__link{display:inline-flex;align-items:center;gap:6px;min-height:24px;color:var(--link);font-weight:500}
.notice__link svg{width:14px;height:14px;flex:none}
.notice__link:hover{text-decoration:underline;text-underline-offset:3px}
.notice__x{position:absolute;right:20px;top:50%;transform:translateY(-50%);width:28px;height:28px;display:grid;place-items:center;border-radius:var(--r-sm);color:var(--muted);cursor:pointer}
.notice__x svg{width:14px;height:14px}
.notice__x:hover{background:var(--panel-2);color:var(--text)}
#site-header{position:relative;z-index:40}
.masthead{position:relative;z-index:43;height:var(--header-height);border-bottom:1px solid var(--line-soft);background:var(--bg-top)}
.masthead .wrap{height:100%;display:flex;align-items:center;gap:36px;flex-wrap:nowrap}
.brand{display:inline-flex;align-items:center;gap:10px;flex:none;min-height:32px;white-space:nowrap}
.brand img{width:32px;height:32px;flex:none}
.brand__name{font-family:var(--font-display);font-size:19px;font-weight:600;letter-spacing:-.015em;color:var(--text)}
.brand__zh{font-size:14px;font-weight:400;color:var(--muted)}
.tabs{display:flex;align-items:stretch;height:100%;flex:1;min-width:0}
.tabs ul{display:flex;align-items:center;list-style:none;margin:0;padding:0;gap:0;height:100%}
.tabs li{height:100%;flex:none}
.tabs a{position:relative;display:flex;align-items:center;justify-content:center;height:100%;padding:0 14px;font-size:15px;color:var(--muted);white-space:nowrap;transition:color var(--fast)}
.tabs a::after{content:"";position:absolute;left:14px;right:14px;bottom:-1px;height:2px;border-radius:var(--r-xs);background:var(--accent);transform:scaleX(0);transition:transform .25s var(--ease)}
.tabs a:hover{color:var(--text)}
.tabs a:hover::after{transform:scaleX(.35)}
.tabs a[aria-current="page"]{color:var(--text);font-weight:500}
.tabs a[aria-current="page"]::after{transform:scaleX(1)}
.mast-right{display:flex;align-items:center;gap:10px;flex-shrink:0;margin-left:auto}
.lang-picker{position:relative;flex-shrink:0}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;height:36px;padding:0 12px;border-radius:var(--r-sm);border:1px solid var(--clear);font-size:14px;color:var(--muted);cursor:pointer;list-style:none}
.lang::-webkit-details-marker{display:none}
.lang span{white-space:nowrap}
.lang svg{width:16px;height:16px;flex:none}
.lang:hover{border-color:var(--border);color:var(--text)}
.lang-menu{position:absolute;right:0;top:calc(100% + 10px);z-index:46;width:188px;padding:8px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--shadow-panel)}
.lang-menu a{display:flex;align-items:center;width:100%;min-height:44px;padding:10px 12px;border-radius:var(--r-sm);font-size:14px;white-space:nowrap}
.lang-menu a:hover,.lang-menu a[aria-current="true"]{background:var(--panel-2);color:var(--text)}
.btn-login{display:inline-flex;align-items:center;justify-content:center;height:36px;padding:0 18px;border-radius:var(--r-sm);background:var(--text);color:var(--panel);font-size:14px;font-weight:500;white-space:nowrap;box-shadow:inset 0 1px 0 var(--w-14),0 8px 18px -10px var(--ink-35)}
.btn-login:hover{background:var(--ink-2)}
.nav-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;border-radius:var(--r-sm);color:var(--text)}
.nav-toggle__line{display:block;width:20px;height:2px;background:currentColor}
.nav-toggle[aria-expanded="true"]{background:var(--panel-2)}
.nav-drawer{position:fixed;top:var(--drawer-top);left:0;right:0;z-index:42;height:calc(100dvh - var(--drawer-top));max-height:calc(100dvh - var(--drawer-top));padding:16px var(--gutter) 32px;background:var(--panel);overflow-y:auto;overscroll-behavior:contain;border-top:1px solid var(--border)}
.nav-drawer a{display:flex;align-items:center;width:100%;min-height:48px;padding:12px 16px;border-bottom:1px solid var(--border);color:var(--text)}
.nav-drawer a[aria-current="page"]{background:var(--panel-2);box-shadow:inset 3px 0 0 var(--accent)}
.drawer-languages{display:grid;grid-template-columns:1fr;margin-top:20px}
.nav-veil{position:fixed;inset:var(--drawer-top) 0 0;z-index:41;background:var(--veil)}
html.nav-open{overflow:hidden}
.site-footer{margin-top:56px;padding-top:48px;padding-bottom:24px;border-top:1px solid var(--border);background:var(--panel-2)}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr;gap:48px}
.footer-grid>*{min-width:0}
.footer-brand p{max-width:350px;margin-top:18px;color:var(--muted);line-height:1.8}
.footer-title{font-size:14px;font-weight:600;margin-bottom:14px}
.footer-links{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px 18px}
.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(--link)}
.footer-languages{display:flex;flex-wrap:wrap;gap:10px 24px;margin-top:32px;padding-top:24px;border-top:1px solid var(--border)}
.footer-bottom{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:12px;margin-top:24px;font-size:13px;color:var(--muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:20px}
.reveal{transition:opacity var(--reveal-time) var(--ease),transform var(--reveal-time) var(--ease)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:relative;display:block;min-height:120px;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(max-width:1180px){
  .masthead .wrap{gap:20px}
  .tabs a{padding-inline:10px;font-size:14px}
  .tabs a::after{left:10px;right:10px}
}
@media(max-width:1080px){
  .tabs{display:none}
  .mast-right{margin-left:auto}
  .nav-toggle{display:inline-flex}
  .grid--five{grid-template-columns:repeat(3,minmax(0,1fr))}
}
@media(max-width:768px){
  h1{font-size:clamp(28px,5vw,40px);line-height:1.15}
  .sec{padding-top:48px;padding-bottom:48px}
  .footer-grid{grid-template-columns:1fr 1fr;gap:32px}
  .footer-brand{grid-column:1/-1}
  .grid--three{grid-template-columns:1fr}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .wrap{width:100%;padding-inline:var(--gutter)}
  .notice{min-height:40px;padding:9px 44px;flex-wrap:wrap;gap:4px 10px;font-size:12.5px;text-align:center}
  .notice__x{right:8px}
  .masthead .wrap{gap:8px}
  .brand{gap:6px}
  .brand img{width:26px;height:26px}
  .brand__name{font-size:17px}
  .brand__zh{font-size:12px}
  .mast-right{gap:2px;margin-left:auto}
  .lang{padding-inline:5px;font-size:11px;gap:3px}
  .lang svg{width:13px;height:13px}
  .btn-login{padding-inline:11px;font-size:13px}
  .panel,.card{padding:20px}
  .grid--five{grid-template-columns:repeat(2,minmax(0,1fr))}
  .tilt,.layer,.float-stamp{transform:none}
  .top,.decor-section{overflow-x:clip;max-width:100%}
  .footer-grid{grid-template-columns:1fr;gap:28px}
  .footer-brand{grid-column:auto}
}
@media(max-width:360px){
  .brand__name{font-size:15px}
  .brand img{width:24px;height:24px}
  .lang{font-size:10px;padding-inline:3px}
  .lang svg{display:none}
  .btn-login{padding-inline:9px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition:none!important;animation:none!important}
  .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none}
}