:root{
  --bg:#FFFFFF;
  --bg-panel:#F7F6F8;
  --bg-panel-2:#EFEDF2;
  --border:#E4E1E8;
  --accent:#FF4F7B;
  --accent-dark:#C8264F;
  --lilac:#F08BE6;
  --mint:#9BE7B0;
  --sky:#9ED8F5;
  --lemon:#E9F26B;
  --text:#16141A;
  --text-muted:#5E5A66;
  --ink:#141218;
  --ink-2:#2A2631;
  --white:#FFFFFF;
  --porcelain:#FCFBFD;
  --success:#1F9E5A;
  --warn:#D98A0B;
  --error:#D42F2F;
  --peach-glow:rgba(255,196,170,.34);
  --coral-wash:rgba(255,79,123,.055);
  --track:rgba(239,237,242,.72);
  --white-90:rgba(255,255,255,.92);
  --ink-hl:rgba(255,255,255,.16);
  --tint-10:rgba(255,79,123,.10);
  --tint-14:rgba(255,79,123,.14);
  --tint-24:rgba(255,79,123,.24);
  --ink-06:rgba(20,18,24,.06);
  --ink-28:rgba(20,18,24,.28);
  --veil:rgba(20,18,24,.38);
  --dot-grid:rgba(255,255,255,.18);
  --flag-red:#D7263D;
  --flag-blue:#1E3A8A;
  --flag-white:#FFFFFF;
  --clear:transparent;
  --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,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --fs-xs:12px;
  --fs-label:13px;
  --fs-sm:14px;
  --fs-button:15px;
  --fs-body:16px;
  --fs-card:17px;
  --fs-lead-mobile:17px;
  --fs-lead:20px;
  --fs-h3:24px;
  --fs-h2:36px;
  --fs-h2-mobile:28px;
  --fs-display:66px;
  --fs-display-small:52px;
  --fs-display-mobile:38px;
  --fs-display-narrow:34px;
  --fs-price:40px;
  --weight-regular:400;
  --weight-medium:500;
  --weight-semibold:600;
  --weight-bold:700;
  --weight-brand:800;
  --tracking-display:-.03em;
  --tracking-heading:-.02em;
  --tracking-small:-.01em;
  --tracking-label:.04em;
  --r-xl:28px;
  --r-lg:24px;
  --r-md:16px;
  --r-sm:8px;
  --r-tag:7px;
  --r-tip:3px;
  --r-circle:50%;
  --r-pill:999px;
  --shadow-float:0 24px 48px -20px var(--tint-24),0 6px 16px -8px var(--tint-10);
  --shadow-soft:0 14px 32px -14px var(--tint-14),0 2px 6px var(--ink-06);
  --shadow-high:0 30px 56px -20px var(--tint-24),0 6px 16px -8px var(--tint-14);
  --shadow-button:inset 0 1px 0 var(--ink-hl),0 10px 20px -10px var(--ink-28);
  --shadow-inner:inset 0 0 0 1px var(--white-90);
  --gutter:24px;
  --content-width:1248px;
  --reading-width:800px;
  --head-height:72px;
  --anchor-offset:88px;
  --toc-offset:152px;
  --ease:cubic-bezier(.2,.7,.2,1);
  --duration-fast:.2s;
  --duration-reveal:.35s;
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:var(--anchor-offset)}
html,body{margin:0;padding:0}
body{font-family:var(--font-body);font-size:var(--fs-body);line-height:1.75;color:var(--text);background:var(--bg);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
html.nav-open{overflow:hidden}
img,video{display:block;max-width:100%;height:auto}
svg{flex-shrink:0}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
button:disabled,[aria-disabled="true"]{cursor:not-allowed}
a{color:inherit;text-underline-offset:4px}
:focus-visible{outline:2px solid var(--accent-dark);outline-offset:3px;border-radius:var(--r-sm)}
[hidden]{display:none!important}
h1,h2,h3,h4{font-family:var(--font-display);font-weight:var(--weight-bold);line-height:1.25;text-wrap:balance;overflow-wrap:break-word}
h1{font-size:clamp(var(--fs-display-small),5vw,var(--fs-display));letter-spacing:var(--tracking-heading)}
h2{font-size:var(--fs-h2);letter-spacing:var(--tracking-heading)}
h3{font-size:var(--fs-h3)}
p{margin-block:0 20px}
h1,h2,h3{margin-block:0 24px}
section[id],h2[id],h3[id]{scroll-margin-top:var(--anchor-offset)}
code{font-family:var(--font-mono);overflow-wrap:anywhere;font-size:.9em}
pre{max-width:100%;overflow-x:auto;padding:24px;border:1px solid var(--border);border-radius:var(--r-md);background:var(--bg-panel);line-height:1.65}
pre code{overflow-wrap:normal;white-space:pre}
blockquote{margin-inline:0}
table{border-collapse:collapse}
th,td{text-align:left}
.no-break{white-space:nowrap}
.mono{font-family:var(--font-mono);font-feature-settings:"tnum";font-variant-numeric:tabular-nums;letter-spacing:var(--tracking-small)}
.muted{color:var(--text-muted)}
.grad{background:linear-gradient(90deg,var(--accent),var(--lilac));-webkit-background-clip:text;background-clip:text;color:var(--clear)}
.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:80px;padding-bottom:80px}
.section-panel{background:var(--bg-panel)}
.section-head{max-width:760px;margin-bottom:40px}
.lead{font-size:var(--fs-lead);line-height:1.6;color:var(--text-muted)}
.eyebrow{margin:0;font-size:var(--fs-label);font-weight:var(--weight-semibold);letter-spacing:.06em;color:var(--accent-dark)}
.stack>*+*{margin-top:24px}
.grid{display:grid;gap:24px}
.grid>*{min-width:0}
.grid-three{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-two{grid-template-columns:repeat(2,minmax(0,1fr))}
.actions{display:flex;align-items:center;flex-wrap:wrap;gap:12px}
.panel,.card{min-width:0;padding:28px;background:var(--white);border:1px solid var(--border);border-radius:var(--r-lg);box-shadow:var(--shadow-inner),var(--shadow-soft)}
.panel-soft{background:linear-gradient(160deg,var(--white),var(--bg-panel))}
.btn,.btn-primary,.btn-ghost,.btn-secondary,.btn-login{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:48px;padding:12px 24px;border:1px solid var(--clear);border-radius:var(--r-pill);font-size:var(--fs-button);font-weight:var(--weight-semibold);line-height:1.4;text-decoration:none;white-space:nowrap;flex-shrink:0;transition:background-color var(--duration-fast),transform var(--duration-fast),color var(--duration-fast)}
.btn-primary{background:var(--ink);color:var(--white);box-shadow:var(--shadow-button)}
.btn-primary:hover{background:var(--ink-2);transform:translateY(-1px)}
.btn-secondary,.btn-ghost{background:var(--white);border-color:var(--ink);color:var(--text)}
.btn-secondary:hover,.btn-ghost:hover{background:var(--bg-panel)}
.btn-primary svg,.btn-secondary svg,.btn-ghost svg{width:16px;height:16px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round;stroke-linejoin:round}
.btn:disabled,.btn-primary:disabled,.btn-secondary:disabled,.btn[aria-disabled="true"]{opacity:.5;transform:none;box-shadow:none}
.btn.is-hover{background:var(--ink-2);color:var(--white)}
.btn.is-focus{outline:2px solid var(--accent-dark);outline-offset:3px}
.btn.is-active{background:var(--accent-dark);color:var(--white)}
.site-head,#site-header{position:relative;z-index:40;min-height:var(--head-height)}
.head-inner{position:relative;z-index:43;max-width:1360px;height:var(--head-height);margin:0 auto;padding:0 40px;display:flex;align-items:center;gap:24px;flex-wrap:nowrap}
.brand{display:inline-flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);flex:none}
.brand-mark{width:34px;height:34px;border-radius:var(--r-circle);flex-shrink:0}
.brand-en{font-family:var(--font-display);font-weight:var(--weight-brand);font-size:var(--fs-lead);letter-spacing:var(--tracking-heading)}
.brand-zh{font-weight:var(--weight-medium);font-size:var(--fs-sm);color:var(--text-muted);padding-left:10px;border-left:1px solid var(--border);line-height:16px}
.nav-pills{flex:1;min-width:0;display:flex;justify-content:center}
.nav-pills ul{display:flex;align-items:center;gap:2px;margin:0;padding:4px;list-style:none;background:var(--track);border:1px solid var(--border);border-radius:var(--r-pill)}
.nav-pills li{flex-shrink:0}
.nav-pills a{display:flex;align-items:center;justify-content:center;min-height:36px;padding:8px 14px;border-radius:var(--r-pill);font-size:var(--fs-sm);font-weight:var(--weight-medium);line-height:20px;color:var(--text-muted);text-decoration:none;white-space:nowrap;transition:color var(--duration-fast),background-color var(--duration-fast)}
.nav-pills a:hover{color:var(--text)}
.nav-pills a.is-active{background:var(--white);color:var(--text);font-weight:var(--weight-semibold);box-shadow:0 0 0 1px var(--border),0 6px 14px -6px var(--tint-24)}
.head-tools{display:flex;align-items:center;gap:8px;flex-shrink:0}
.lang-picker{position:relative}
.lang-switch{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;height:40px;padding:0 12px;border:0;background:var(--clear);border-radius:var(--r-pill);font-size:var(--fs-sm);font-weight:var(--weight-medium);line-height:1;color:var(--text-muted);white-space:nowrap}
.lang-switch:hover{color:var(--text);background:var(--track)}
.lang-switch svg{width:16px;height:16px;fill:none;stroke:currentColor;stroke-width:1.6}
.lang-text{white-space:nowrap}
.lang-caret{font-size:var(--fs-xs)}
.lang-panel{position:absolute;z-index:60;top:calc(100% + 8px);right:0;min-width:176px;padding:8px;background:var(--white);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--shadow-float)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-sm);text-decoration:none;font-size:var(--fs-sm)}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--bg-panel);color:var(--accent-dark)}
.btn-login{height:40px;min-height:40px;padding:0 20px;border-color:var(--ink);background:var(--white);font-size:var(--fs-sm)}
.btn-login:hover{background:var(--ink);color:var(--white)}
.nav-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;padding:8px;border:1px solid var(--border);border-radius:var(--r-circle);background:var(--white);color:var(--ink)}
.nav-toggle-line{display:block;width:20px;height:2px;background:currentColor}
.nav-drawer{display:none;position:fixed;z-index:42;top:var(--head-height);right:0;left:0;height:calc(100dvh - var(--head-height));max-height:calc(100dvh - var(--head-height));padding:16px var(--gutter) 32px;background:var(--white);overflow-y:auto;overscroll-behavior:contain;border-top:1px solid var(--border)}
.nav-drawer.is-open{display:block}
.nav-drawer ul{list-style:none;margin:0;padding:0}
.nav-drawer a{display:flex;align-items:center;width:100%;min-height:48px;padding:12px 16px;border-radius:var(--r-sm);text-decoration:none;font-weight:var(--weight-medium)}
.nav-drawer a:hover,.nav-drawer a.is-active{background:var(--bg-panel);color:var(--accent-dark)}
.drawer-languages{margin-top:16px;padding-top:16px;border-top:1px solid var(--border)}
.nav-veil{position:fixed;z-index:41;inset:var(--head-height) 0 0;background:var(--veil);border:0}
.site-footer{background:linear-gradient(180deg,var(--bg-panel),var(--porcelain));border-top:1px solid var(--border);padding-top:64px;padding-bottom:32px}
.footer-grid{display:grid;grid-template-columns:1.35fr 1fr 1fr 1fr;gap:40px}
.footer-grid>*{min-width:0}
.footer-intro{margin-top:20px;color:var(--text-muted);font-size:var(--fs-sm)}
.footer-title{margin:0 0 16px;font-size:var(--fs-body);font-weight:var(--weight-semibold)}
.footer-links{list-style:none;margin:0;padding:0;display:grid;gap:4px}
.footer-links a{display:inline-flex;align-items:center;min-height:28px;padding-block:2px;text-decoration:none;font-size:var(--fs-sm);color:var(--text-muted)}
.footer-links a:hover{color:var(--accent-dark);text-decoration:underline}
.footer-bottom{margin-top:40px;padding-top:24px;border-top:1px solid var(--border);display:flex;justify-content:space-between;align-items:center;gap:16px;flex-wrap:wrap;font-size:var(--fs-sm);color:var(--text-muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:20px}
.footer-legal a{display:inline-flex;align-items:center;min-height:28px}
.reveal{transition:opacity var(--duration-reveal) var(--ease),transform var(--duration-reveal) var(--ease)}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{position:relative;display:block;min-height:96px;min-width:0;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:24px}
#server-status>*{min-width:0;max-width:100%}
#server-status+*{margin-top:24px}
.prose{min-width:0;overflow-wrap:break-word}
.prose h2{margin-top:56px}
.prose h3{margin-top:32px}
.prose li+li{margin-top:8px}
.prose a{color:var(--accent-dark)}
.prose img{border-radius:var(--r-md)}
.decorated-section{position:relative;overflow-x:clip;max-width:100%}
.svg-defs{position:absolute;width:0;height:0;overflow:hidden}
@media(max-width:1320px){
  .head-inner{gap:16px;padding-inline:24px}
  .nav-pills a{padding-inline:10px}
}
@media(max-width:1180px){
  .nav-pills{display:none}
  .head-inner{justify-content:space-between}
  .head-tools{margin-left:auto}
  .nav-toggle{display:inline-flex}
}
@media(min-width:1181px){
  .nav-drawer.is-open,.nav-veil{display:none}
  html.nav-open{overflow:auto}
}
@media(max-width:900px){
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .grid-three{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:768px){
  h1{font-size:var(--fs-display-mobile);line-height:1.15}
  h2{font-size:var(--fs-h2-mobile)}
  .section{padding-top:56px;padding-bottom:56px}
  .grid-two,.grid-three{grid-template-columns:minmax(0,1fr)}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .head-inner{padding-inline:16px;gap:8px}
  .head-tools{gap:4px;margin-left:auto}
  .brand{gap:7px}
  .brand-en{font-size:var(--fs-card)}
  .brand-mark{width:30px;height:30px}
  .brand-zh,.lang-text{display:none}
  .lang-switch{padding-inline:6px}
  .btn-login{padding-inline:14px}
  .card,.panel{padding:24px}
  .footer-grid{grid-template-columns:minmax(0,1fr);gap:28px}
  .footer-bottom{align-items:flex-start;flex-direction:column}
  .tilt,[data-tilt]{transform:none}
  .decorated-section{max-width:100%;overflow-x:clip}
  .lead{font-size:var(--fs-lead-mobile)}
}
@media(max-width:360px){
  .head-inner{gap:4px}
  .brand-mark{width:26px;height:26px}
  .btn-login{padding-inline:10px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none;transition:none}
  .btn,.btn-primary,.btn-secondary,.btn-ghost,.btn-login,.nav-pills a{transition:none}
  .btn-primary:hover{transform:none}
}