:root {
  --bg:#E8EEFA;
  --bg-top:#F2F5FC;
  --bg-bottom:#E1E8F6;
  --bg-panel:#F7F9FE;
  --bg-panel-2:#DCE4F4;
  --border:#CBD5EA;
  --accent:#1E3F8F;
  --accent-dark:#14295F;
  --text:#131B2E;
  --text-muted:#56607A;
  --success:#12916F;
  --warn:#C9821A;
  --error:#C8354B;
  --white:#FFFFFF;
  --on-dark:#E9EEFB;
  --glow-blue:#A9C6FF;
  --glow-orange:#FFC59A;
  --glow-pink:#F6B3D6;
  --glow-yellow:#FFE3A0;
  --flag-red:#D52B3A;
  --flag-white:#FFFFFF;
  --flag-blue:#22408C;
  --flag-outline:color-mix(in srgb,var(--text) 14%,transparent);
  --accent-bright:color-mix(in srgb,var(--accent) 72%,var(--white));
  --rail:var(--border);
  --rail-soft:color-mix(in srgb,var(--border) 70%,transparent);
  --glass:color-mix(in srgb,var(--bg-panel) 58%,transparent);
  --glass-edge:color-mix(in srgb,var(--white) 78%,transparent);
  --veil-color:color-mix(in srgb,var(--accent-dark) 32%,transparent);
  --font-display:"Inter","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --r-node:4px;
  --r-xs:6px;
  --r-sm:10px;
  --r-button:12px;
  --r-md:13px;
  --r-lg:16px;
  --r-scene:18px;
  --r-xl:24px;
  --r-2xl:32px;
  --r-nose:44px;
  --r-pill:999px;
  --hi-edge:inset 0 1px 0 color-mix(in srgb,var(--white) 92%,transparent);
  --shadow-panel:0 34px 80px -28px color-mix(in srgb,var(--accent) 10%,transparent),0 14px 36px -18px color-mix(in srgb,var(--accent) 10%,transparent),0 2px 6px color-mix(in srgb,var(--accent) 5%,transparent);
  --shadow-car:0 18px 40px -14px color-mix(in srgb,var(--accent) 12%,transparent),0 2px 6px color-mix(in srgb,var(--accent) 6%,transparent);
  --shadow-chip:0 6px 16px -8px color-mix(in srgb,var(--accent) 14%,transparent);
  --gutter:24px;
  --content-width:1320px;
  --reading-width:820px;
  --head-height:94px;
  --anchor-offset:110px;
  --toc-offset:174px;
  --text-xs:12px;
  --text-sm:14px;
  --text-base:16px;
  --text-lg:20px;
  --title-h1:clamp(52px,5vw,68px);
  --title-h2:clamp(28px,3vw,40px);
  --title-h3:22px;
  --weight-normal:400;
  --weight-medium:500;
  --weight-semibold:600;
  --weight-bold:700;
  --weight-brand:800;
  --weight-display:900;
  --ease-time:.2s;
  --reveal-time:.35s;
}
*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%;scroll-padding-top:var(--anchor-offset);scroll-behavior:smooth}
body{font-family:var(--font-body);font-size:var(--text-base);color:var(--text);background:var(--bg);line-height:1.6;-webkit-font-smoothing:antialiased}
a{color:inherit;text-decoration:none}
ul,ol{list-style:none}
button,input,select,textarea{font:inherit}
button{cursor:pointer}
button:disabled,[aria-disabled="true"]{cursor:not-allowed;opacity:.55}
button{color:inherit}
img{display:block;max-width:100%;height:auto}
svg{vertical-align:middle;flex-shrink:0}
[hidden]{display:none!important}
:where(a,button,input,select,textarea,summary,[tabindex]):focus-visible{outline:2px solid var(--accent);outline-offset:3px}
::selection{background:var(--bg-panel-2);color:var(--accent-dark)}
h1,h2,h3{font-family:var(--font-display);text-wrap:balance;overflow-wrap:break-word}
h1{font-size:var(--title-h1);font-weight:var(--weight-display);line-height:1.12;letter-spacing:-.02em}
h2{font-size:var(--title-h2);font-weight:var(--weight-brand);line-height:1.25;letter-spacing:-.02em}
h3{font-size:var(--title-h3);font-weight:var(--weight-bold);line-height:1.4}
p{overflow-wrap:break-word}
code{font-family:var(--font-mono);font-size:.88em;overflow-wrap:anywhere;color:var(--accent-dark)}
pre{max-width:100%;overflow-x:auto;padding:20px;border:1px solid var(--border);border-radius:var(--r-lg);background:var(--bg-panel-2)}
pre code{white-space:pre;overflow-wrap:normal}
.no-break{white-space:nowrap}
.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}
.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)}
.sec{padding-top:72px;padding-bottom:72px}
.stack>*+*{margin-top:20px}
.grid{display:grid;gap:24px}
.grid>*,:where(.head-in,.footer-grid,.ctas,.promo-block,.feature-layout,.train)>*{min-width:0}
.grid-three{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-two{grid-template-columns:repeat(2,minmax(0,1fr))}
.muted{color:var(--text-muted)}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums}
.panel,.card{min-width:0;background:var(--bg-panel);border:1px solid var(--border);border-radius:var(--r-xl);box-shadow:var(--hi-edge),var(--shadow-panel);padding:28px}
.prose{min-width:0;overflow-wrap:break-word;line-height:1.85}
.prose p,.prose ul,.prose ol,.prose pre,.prose blockquote{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{list-style:decimal;padding-left:24px}
.prose a{color:var(--accent);text-decoration:underline;text-underline-offset:4px}
.prose li+li{margin-top:8px}
.prose :first-child{margin-top:0}
.stage{background:linear-gradient(180deg,var(--bg-top) 0%,var(--bg) 58%,var(--bg-bottom) 100%);overflow-x:clip;max-width:100%}
.decorated-section{position:relative;overflow-x:clip;max-width:100%}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;padding:10px 22px;border:1px solid transparent;border-radius:var(--r-button);font-size:15px;font-weight:var(--weight-semibold);letter-spacing:.01em;line-height:24px;flex-shrink:0;white-space:nowrap;transition:transform var(--ease-time) ease,box-shadow var(--ease-time) ease,border-color var(--ease-time) ease}
.btn svg{width:18px;height:18px}
.btn-primary{color:var(--white);background:linear-gradient(180deg,var(--accent),var(--accent-dark));box-shadow:inset 0 1px 0 color-mix(in srgb,var(--white) 22%,transparent),0 12px 26px -12px color-mix(in srgb,var(--accent) 60%,transparent)}
.btn-primary:hover,.btn-primary.is-hover{transform:translateY(-1px)}
.btn-primary .arr{font-family:var(--font-mono);font-weight:var(--weight-medium)}
.btn-ghost,.btn-secondary{color:var(--text);background:var(--white);border:1px solid var(--border);box-shadow:var(--hi-edge)}
.btn-ghost:hover,.btn-secondary:hover,.btn-ghost.is-hover{border-color:var(--text-muted)}
.btn:active{transform:translateY(1px)}
.btn.is-focus{outline:2px solid var(--accent);outline-offset:3px}
.btn-small{min-height:36px;padding:5px 14px;font-size:var(--text-sm)}
.ctas{display:flex;justify-content:center;flex-wrap:wrap;gap:12px;margin-top:20px}
#site-header{position:sticky;top:0;z-index:80}
.announce{display:flex;align-items:center;justify-content:center;gap:10px;min-height:34px;padding:4px 16px;font-size:13px;letter-spacing:.01em;color:var(--on-dark);background-color:var(--accent-dark);background-image:repeating-linear-gradient(135deg,color-mix(in srgb,var(--white) 6%,transparent) 0 1px,transparent 1px 9px)}
.announce .sep{opacity:.55}
.announce .go{display:inline-flex;align-items:center;gap:6px;min-height:24px}
.site-head{position:relative;z-index:82;border-bottom:1px solid var(--rail);background:var(--bg-top)}
.head-in{width:min(1320px,calc(100% - 96px));margin:0 auto;height:60px;display:flex;align-items:center;gap:28px;flex-wrap:nowrap}
.brand{display:inline-flex;align-items:center;gap:10px;font-family:var(--font-display);font-weight:var(--weight-brand);font-size:18px;letter-spacing:-.015em;color:var(--text);flex-shrink:0;white-space:nowrap;min-height:30px}
.brand img{width:30px;height:30px;flex-shrink:0}
.brand-zh{font-weight:var(--weight-medium);color:var(--text-muted)}
.logo-mark{display:grid;place-items:center;width:30px;height:30px;border-radius:var(--r-pill);color:var(--white);background:linear-gradient(150deg,var(--accent-bright),var(--accent) 55%,var(--accent-dark));box-shadow:var(--hi-edge),0 6px 14px -6px color-mix(in srgb,var(--accent) 40%,transparent);flex-shrink:0}
.logo-mark img{width:100%;height:100%}
.logo-mark svg{width:17px;height:17px}
.nav{margin-left:auto;flex:1;min-width:0}
.nav ul{display:flex;align-items:center;justify-content:flex-end;list-style:none;margin:0;padding:0}
.nav li{display:flex;align-items:center;font-size:14px;color:var(--text-muted);white-space:nowrap}
.nav li+li::before{content:"·";margin:0 11px;color:color-mix(in srgb,var(--text-muted) 55%,transparent)}
.nav a{display:inline-flex;align-items:center;min-height:32px;transition:color var(--ease-time) ease}
.nav a:hover{color:var(--text)}
.nav a[aria-current="page"]{color:var(--text);font-weight:var(--weight-semibold)}
.head-tools{display:flex;align-items:center;gap:8px;flex-shrink:0}
.language-picker{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:4px;min-height:34px;min-width:44px;width:auto;padding:0 10px;border:0;border-radius:var(--r-sm);background:transparent;color:var(--text-muted);font-size:13px;cursor:pointer;white-space:nowrap}
.lang span{white-space:nowrap}
.lang:hover{background:var(--bg-panel-2);color:var(--text)}
.lang-panel{position:absolute;right:0;top:calc(100% + 10px);z-index:90;min-width:168px;padding:6px;background:var(--bg-panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--shadow-panel)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-sm);font-size:14px;white-space:nowrap}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--bg-panel-2);color:var(--accent)}
.login{display:inline-flex;align-items:center;justify-content:center;gap:6px;height:36px;min-width:60px;padding:0 16px;border-radius:var(--r-sm);border:1px solid var(--border);background:var(--white);font-size:14px;font-weight:var(--weight-semibold);color:var(--text);box-shadow:var(--hi-edge),var(--shadow-chip);transition:border-color var(--ease-time) ease;white-space:nowrap}
.login:hover{border-color:var(--accent)}
.login svg{width:14px;height:14px;color:var(--accent)}
.menu-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;padding:10px;border:1px solid var(--border);border-radius:var(--r-sm);background:var(--bg-panel);color:var(--accent)}
.menu-line{display:block;width:20px;height:2px;background:currentColor;flex-shrink:0}
.menu-toggle[aria-expanded="true"] .menu-line:first-child{transform:translateY(6px) rotate(45deg)}
.menu-toggle[aria-expanded="true"] .menu-line:nth-child(2){opacity:0}
.menu-toggle[aria-expanded="true"] .menu-line:last-child{transform:translateY(-6px) rotate(-45deg)}
.nav-drawer{display:none}
.nav-veil{display:none}
html.nav-open{overflow:hidden}
.frame{position:relative;width:min(1320px,calc(100% - 96px));margin:0 auto;border-left:1px solid var(--rail);border-right:1px solid var(--rail)}
.hrule{position:relative;height:1px;margin-top:16px;background:var(--rail)}
.hrule::before,.hrule::after,.fold::before,.fold::after,.band::before,.band::after{content:"";position:absolute;top:-6px;width:13px;height:13px;border-radius:var(--r-node);border:1px solid var(--border);background:var(--bg-panel);box-shadow:var(--hi-edge)}
.hrule::before,.fold::before,.band::before{left:-7px}
.hrule::after,.fold::after,.band::after{right:-7px}
.band{position:relative;height:48px;border-block:1px solid var(--rail);margin-top:32px;background:repeating-linear-gradient(135deg,transparent 0 5px,var(--rail-soft) 5px 6px,transparent 6px 10px)}
.site-footer{border-top:1px solid var(--border);background:var(--bg-panel-2);padding-top:48px;padding-bottom:24px}
.footer-grid{display:grid;grid-template-columns:1.25fr 1.5fr 1fr;gap:40px}
.footer-brand p{max-width:34ch;margin-top:16px;color:var(--text-muted);font-size:14px}
.footer-title{font-size:14px;font-weight:var(--weight-bold);margin-bottom:14px;color:var(--accent-dark)}
.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:6px 18px}
.footer-links a,.footer-hot a,.footer-languages a,.footer-legal a{display:inline-flex;align-items:center;min-height:28px;font-size:14px}
.footer-links a:hover,.footer-hot a:hover,.footer-languages a:hover,.footer-legal a:hover{color:var(--accent);text-decoration:underline;text-underline-offset:4px}
.footer-hot{display:grid;gap:4px}
.footer-languages{display:flex;flex-wrap:wrap;gap:6px 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;color:var(--text-muted);font-size:13px}
.footer-legal{display:flex;flex-wrap:wrap;gap:16px}
.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:relative;display:block;min-width:0;max-width:100%;overflow:hidden;margin-block:24px}
#server-status+*{margin-top:24px}
#server-status :where(.grid,[class*="grid"]){min-width:0;max-width:100%}
@media(min-width:1101px) and (max-width:1350px){
  .head-in{width:calc(100% - 48px);gap:16px}
  .nav li{font-size:12px}
  .nav li+li::before{margin-inline:7px}
  .lang{padding-inline:6px}
}
@media(max-width:1100px){
  .head-in{width:calc(100% - 48px);gap:16px}
  .nav{display:none}
  .head-tools{margin-left:auto}
  .menu-toggle{display:inline-flex}
  .nav-drawer{position:fixed;z-index:81;top:var(--head-height);left:0;right:0;height:calc(100dvh - var(--head-height));max-height:calc(100dvh - var(--head-height));overflow-y:auto;overscroll-behavior:contain;background:var(--bg-panel);padding:16px var(--gutter) 32px;border-top:1px solid var(--border)}
  .nav-drawer:not([hidden]){display:block}
  .nav-drawer ul{list-style:none;margin:0;padding:0}
  .nav-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:10px 16px;border-radius:var(--r-sm)}
  .nav-drawer a:hover,.nav-drawer a[aria-current="page"]{background:var(--bg-panel-2);color:var(--accent)}
  .drawer-languages{border-top:1px solid var(--border);margin-top:16px;padding-top:16px}
  .nav-veil:not([hidden]){display:block;position:fixed;inset:var(--head-height) 0 0;z-index:79;background:var(--veil-color);border:0;width:100%}
}
@media(max-width:768px){
  :root{--title-h1:clamp(28px,7vw,40px);--title-h2:28px;--gutter:20px}
  .sec{padding-top:48px;padding-bottom:48px}
  .grid-three,.grid-two{grid-template-columns:minmax(0,1fr)}
  .frame{width:calc(100% - 40px)}
  .footer-grid{grid-template-columns:minmax(0,1fr);gap:28px}
  .footer-bottom{align-items:flex-start;flex-direction:column}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .head-in{width:calc(100% - 32px);gap:8px}
  .brand{gap:6px;font-size:15px}
  .brand img{width:26px;height:26px}
  .head-tools{gap:4px;margin-left:auto}
  .login{padding-inline:10px;min-width:48px;font-size:13px}
  .login svg{display:none}
  .lang{font-size:11px;padding-inline:4px}
  .announce{font-size:11px;gap:6px;white-space:nowrap}
  .frame{width:calc(100% - 32px)}
  .panel,.card{padding:20px}
  .tilt,.is-tilted,[data-tilt],.stub{transform:none}
  .decorated-section{max-width:100%;overflow-x:clip}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition-duration:0s!important;animation:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}