:root{
  --bg:#E9EDF6;
  --bg-top:#F1F4FA;
  --panel:#F8FAFE;
  --panel-2:#DCE3F0;
  --panel-3:#EEF2F9;
  --white:#FFFFFF;
  --border:#CCD5E4;
  --border-soft:#E2E8F2;
  --text:#1C2230;
  --text-soft:#3A4456;
  --muted:#5A6578;
  --faint:#8C96A8;
  --accent:#D64A44;
  --accent-2:#C43F3A;
  --accent-dark:#A8312D;
  --wine:#6E2422;
  --accent-tint:#FBEAE8;
  --cobalt:#3E6BD6;
  --mint:#1F9D6B;
  --mint-tint:#E3F4EC;
  --violet:#7A5BD6;
  --warn:#C98A12;
  --error:#B42335;
  --ink:#1C2230;
  --on-ink:#D8DEEA;
  --graphite:#232A38;
  --graphite-hi:#2F3748;
  --graphite-lo:#171C27;
  --graphite-notch:#434D61;
  --hl:rgba(255,255,255,.18);
  --hl-soft:rgba(255,255,255,.08);
  --glare:rgba(255,255,255,.07);
  --flag-red:#C8333B;
  --flag-blue:#28418C;
  --flag-white:#FFFFFF;
  --flag-ring:rgba(28,34,48,.14);
  --clear:transparent;
  --sh-stage:inset 0 1px 0 rgba(255,255,255,.9),0 40px 90px -30px rgba(214,74,68,.10),0 14px 36px -14px rgba(214,74,68,.10),0 2px 6px rgba(28,34,48,.04);
  --sh-float:0 14px 32px -10px rgba(214,74,68,.16),0 4px 10px -2px rgba(28,34,48,.08);
  --sh-float-deep:0 28px 54px -16px rgba(28,34,48,.24),0 12px 26px -10px rgba(214,74,68,.18);
  --sh-screen:0 30px 54px -22px rgba(28,34,48,.48);
  --sh-window:0 14px 30px -10px rgba(30,8,8,.55);
  --sh-floor:rgba(28,34,48,.34);
  --sh-cta:0 10px 22px -8px rgba(214,74,68,.45);
  --r-xs:4px;
  --r-sm:6px;
  --r-md:8px;
  --r-card:10px;
  --r-lg:12px;
  --r-screen:16px;
  --r-capsule:18px;
  --r-pill:999px;
  --r-circle:50%;
  --r-flag:3px;
  --r-switch:1px;
  --r-row:5px;
  --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 GB','Microsoft YaHei',system-ui,sans-serif;
  --f-mono:'JetBrains Mono',ui-monospace,'SFMono-Regular',Menlo,Consolas,monospace;
  --gutter:24px;
  --content-width:1240px;
  --reading-width:800px;
  --header-height:96px;
  --anchor-offset:112px;
  --toc-offset:16px;
  --toc-landing:96px;
  --ease-short:.2s;
  --reveal-time:.35s;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-offset);scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--f-body);font-size:16px;line-height:1.6;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
button:disabled,.btn[aria-disabled="true"]{cursor:not-allowed;opacity:.55}
img{max-width:100%;height:auto}
svg{flex-shrink:0}
ul,ol{margin:0;padding:0;list-style:none}
p{margin:0}
h1,h2,h3,h4{font-family:var(--f-display);font-weight:700;text-wrap:balance}
h1{font-size:clamp(52px,5vw,68px);line-height:1.12;letter-spacing:-.02em;margin:0 0 24px}
h2{font-size:clamp(28px,3vw,40px);line-height:1.25;letter-spacing:-.02em;margin:0 0 20px}
h3{font-size:22px;line-height:1.35;margin:0 0 12px}
[hidden]{display:none!important}
:focus-visible{outline:2px solid var(--cobalt);outline-offset:3px;border-radius:var(--r-xs)}
::selection{background:var(--accent-tint);color:var(--accent-dark)}
.wrap{width:100%;max-width:var(--content-width);margin-inline:auto;padding-inline:var(--gutter)}
.reading-wrap{width:100%;max-width:var(--reading-width);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-top:64px;padding-bottom:64px}
.section-head{margin-bottom:32px;max-width:760px}
.section-head p,.muted{color:var(--muted)}
.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}
.skip{position:absolute;left:16px;top:-60px;z-index:100;background:var(--white);color:var(--text);padding:8px 14px;border-radius:var(--r-sm);box-shadow:var(--sh-float)}
.skip:focus{top:8px}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.grid{display:grid;gap:24px}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid>*{min-width:0}
.panel,.card{min-width:0;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-lg);padding:28px;box-shadow:var(--sh-float)}
.panel--sunken{background:var(--panel-2);box-shadow:none}
.card-title{font-size:20px;margin-bottom:12px}
.flow>*+*{margin-top:20px}
.prose{min-width:0;overflow-wrap:break-word}
.prose p,.prose ul,.prose ol,.prose blockquote,.prose pre,.prose table{margin-block:20px}
.prose h2{margin-top:48px}
.prose h3{margin-top:32px}
.prose a:not(.btn){text-decoration:underline;text-underline-offset:4px;color:var(--accent-dark)}
.prose ul{list-style:disc;padding-left:24px}
.prose ol{list-style:decimal;padding-left:24px}
.prose li+li{margin-top:8px}
code{font-family:var(--f-mono);font-size:.9em;overflow-wrap:anywhere;background:var(--panel-2);border-radius:var(--r-xs);padding:2px 5px}
pre{max-width:100%;overflow-x:auto;padding:20px;border:1px solid var(--border);border-radius:var(--r-md);background:var(--panel-2)}
pre code{padding:0;background:var(--clear);white-space:pre;overflow-wrap:normal}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;padding:10px 24px;font-size:16px;font-weight:600;line-height:1.4;border:1px solid var(--clear);border-radius:var(--r-md);transition:background var(--ease-short),box-shadow var(--ease-short),color var(--ease-short);flex-shrink:0;white-space:nowrap;text-align:center}
.btn--primary,.btn-primary{background:linear-gradient(180deg,var(--accent),var(--accent-2));color:var(--white);box-shadow:inset 0 1px 0 var(--hl),var(--sh-cta)}
.btn--primary:hover,.btn-primary:hover{background:linear-gradient(180deg,var(--accent-2),var(--accent-dark))}
.btn--secondary,.btn-secondary{background:var(--panel);border-color:var(--border);color:var(--text)}
.btn--secondary:hover,.btn-secondary:hover{background:var(--panel-2)}
.btn--ink{background:var(--text);color:var(--white);box-shadow:inset 0 1px 0 var(--hl)}
.btn--ink:hover{background:var(--text-soft)}
.btn--small{min-height:36px;font-size:14px;padding:7px 16px}
.btn--link{min-height:24px;padding:4px 0;background:var(--clear);color:var(--text);text-decoration:underline;text-decoration-thickness:1.5px;text-underline-offset:6px;border:0}
.btn--link:hover{color:var(--text-soft)}
.cta-row{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;gap:28px;margin-top:24px}
#site-header{position:relative;z-index:40}
.notice{background:var(--ink);color:var(--on-ink);font-family:var(--f-mono);font-size:12px;letter-spacing:.08em;text-transform:uppercase}
.notice__inner{display:flex;align-items:center;justify-content:space-between;gap:20px;height:36px}
.notice__msg{display:flex;align-items:center;gap:10px}
.notice__star{width:15px;height:15px;color:var(--violet)}
.notice__link{display:inline-flex;align-items:center;min-height:24px;color:var(--white);text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:4px;white-space:nowrap}
.notice__link:hover{color:var(--on-ink)}
.topnav{position:relative;z-index:43;background:var(--panel);border-bottom:1px solid var(--border-soft)}
.topnav__inner{display:flex;align-items:center;flex-wrap:nowrap;gap:32px;height:60px}
.brand{display:inline-flex;align-items:center;gap:10px;font-family:var(--f-display);font-weight:700;font-size:19px;letter-spacing:-.02em;color:var(--text);flex-shrink:0;white-space:nowrap;min-height:28px}
.brand__mark{width:28px;height:28px}
.brand__zh{font-size:.85em;font-weight:500;color:var(--muted)}
.mainnav{flex:1;min-width:0}
.mainnav ul{display:flex;align-items:center;justify-content:center;list-style:none;margin:0;padding:0;gap:26px;font-size:15px;color:var(--muted)}
.mainnav li{min-width:0}
.mainnav a{display:inline-flex;align-items:center;min-height:32px;padding:6px 0;white-space:nowrap;transition:color var(--ease-short)}
.mainnav a:hover{color:var(--text)}
.mainnav a[aria-current="page"]{color:var(--text);font-weight:600}
.navtools{display:flex;align-items:center;gap:18px;flex-shrink:0}
.language{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:36px;min-width:44px;width:auto;padding:6px 2px;border:0;background:var(--clear);font-size:14px;color:var(--muted);cursor:pointer;white-space:nowrap}
.lang span{white-space:nowrap}
.lang svg{width:10px;height:10px}
.lang:hover{color:var(--text)}
.language-panel{position:absolute;z-index:60;right:0;top:calc(100% + 8px);width:180px;padding:6px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--sh-float-deep)}
.language-panel a{display:flex;align-items:center;min-height:40px;padding:8px 12px;border-radius:var(--r-sm);font-size:14px}
.language-panel a:hover,.language-panel 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-md);background:var(--text);color:var(--white);font-size:14px;font-weight:600;box-shadow:inset 0 1px 0 var(--hl);white-space:nowrap}
.btn-login:hover{background:var(--text-soft)}
.menu-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;padding:8px;border:0;background:var(--clear);color:var(--text)}
.menu-toggle__line{display:block;width:20px;height:2px;background:currentColor;border-radius:var(--r-switch)}
.mobile-drawer{display:none;position:fixed;z-index:42;left:0;right:0;top:var(--header-height);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}
.mobile-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px 16px;border-radius:var(--r-md)}
.mobile-drawer a:hover,.mobile-drawer a[aria-current="page"]{background:var(--panel-2)}
.drawer-languages{border-top:1px solid var(--border);margin-top:16px;padding-top:16px}
.drawer-languages a[aria-current="true"]{font-weight:700;color:var(--accent-dark)}
html.nav-open{overflow:hidden}
.site-footer{background:var(--panel);border-top:1px solid var(--border);padding-top:48px;padding-bottom:24px}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr;gap:48px}
.footer-brand p{max-width:30em;margin-top:16px;color:var(--muted);font-size:14px}
.footer-heading{font-size:14px;font-weight:700;margin:0 0 12px}
.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 16px;font-size:14px;color:var(--muted)}
.footer-links a{display:inline-flex;align-items:center;min-height:32px;padding-block:4px}
.footer-links a:hover{color:var(--accent-dark);text-decoration:underline;text-underline-offset:4px}
.footer-languages{display:flex;flex-wrap:wrap;gap:8px 20px;margin-top:32px;padding-top:24px;border-top:1px solid var(--border)}
.footer-languages a{display:inline-flex;align-items:center;min-height:32px;font-size:13px;color:var(--muted)}
.footer-languages a[aria-current="true"]{color:var(--text);font-weight:600}
.footer-bottom{display:flex;flex-wrap:wrap;justify-content:space-between;gap:16px;margin-top:20px;font-family:var(--f-mono);font-size:12px;color:var(--muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:16px}
.footer-legal a{display:inline-flex;align-items:center;min-height:24px}
.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{position:static;display:block;min-height:120px;max-width:100%;min-width:0;overflow:hidden;margin-block:24px}
#server-status+*{margin-top:24px}
#server-status>*{min-width:0;max-width:100%}
.decorated-section{position:relative;overflow-x:clip;max-width:100%}
@media(max-width:1180px){.topnav__inner{gap:20px}.mainnav ul{gap:18px}.navtools{gap:12px}}
@media(max-width:1080px){
  :root{--header-height:96px}
  .mainnav{display:none}
  .navtools{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .mobile-drawer.is-open{display:block}
}
@media(max-width:768px){
  :root{--header-height:116px;--gutter:20px}
  h1{font-size:38px;line-height:1.15}
  h2{font-size:28px}
  .section{padding-top:48px;padding-bottom:48px}
  .notice__inner{height:56px;flex-wrap:wrap;justify-content:center;align-content:center;gap:0 14px;font-size:11px}
  .notice__msg{gap:6px}
  .topnav__inner{gap:12px}
  .brand{font-size:17px;gap:7px}
  .navtools{gap:10px;margin-left:auto}
  .lang{font-size:12px}
  .grid--3{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr 1fr;gap:32px}
  .footer-brand{grid-column:1/-1}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .grid--2{grid-template-columns:1fr}
  .panel,.card{padding:22px}
  .tilt,.decorative-tilt,[data-tilt]{transform:none}
  .decorated-section{max-width:100%;overflow-x:clip}
  .footer-grid{grid-template-columns:1fr}
  .footer-brand{grid-column:auto}
}
@media(max-width:420px){
  .brand{font-size:16px;gap:5px}
  .brand__mark{width:24px;height:24px}
  .navtools{gap:5px}
  .btn-login{padding-inline:10px;font-size:12px}
  .lang{font-size:11px;gap:3px}
  .topnav__inner{gap:6px}
}
@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}
}