:root {
  --bg:#E3E9F5;
  --bg-panel:#F7F9FD;
  --bg-panel-2:#D6DFEE;
  --border:#C7D2E6;
  --accent:#1C46E0;
  --accent-dark:#13308F;
  --text:#111A2E;
  --text-muted:#4F5B75;
  --success:#1E9E6A;
  --warn:#C98512;
  --error:#C8323F;
  --wine:#6E1F36;
  --hero-from:#EEF2FA;
  --hero-to:#CFDDF5;
  --globe-hi:#F4F7FE;
  --globe-lo:#B9CCF2;
  --on-accent:#FFFFFF;
  --white:#FFFFFF;
  --clear:transparent;
  --accent-10:rgba(28,70,224,.10);
  --accent-14:rgba(28,70,224,.14);
  --accent-24:rgba(28,70,224,.24);
  --accent-36:rgba(28,70,224,.36);
  --ink-08:rgba(19,48,143,.08);
  --line-globe:rgba(19,48,143,.24);
  --line-globe-strong:rgba(19,48,143,.40);
  --line-equator:rgba(19,48,143,.62);
  --wine-12:rgba(110,31,54,.12);
  --success-14:rgba(30,158,106,.14);
  --grid-line:rgba(17,26,46,.04);
  --glass:rgba(247,249,253,.76);
  --glass-edge:rgba(255,255,255,.85);
  --hi-edge:rgba(255,255,255,.95);
  --white-60:rgba(255,255,255,.6);
  --white-40:rgba(255,255,255,.4);
  --white-24:rgba(255,255,255,.24);
  --groove:rgba(214,223,238,.62);
  --groove-line:rgba(199,210,230,.9);
  --muted-wall:rgba(79,91,117,.52);
  --veil:rgba(17,26,46,.28);
  --flag-red:#D7263D;
  --flag-blue:#1F3A93;
  --flag-green:#16924F;
  --flag-white:#FFFFFF;
  --flag-ring:rgba(17,26,46,.16);
  --r-xs:6px;
  --r-sm:8px;
  --r-md:12px;
  --r-lg:16px;
  --r-pill:999px;
  --r-round:50%;
  --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","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --weight-normal:400;
  --weight-medium:500;
  --weight-bold:600;
  --body-size:17px;
  --body-leading:1.7;
  --display-size:64px;
  --heading-size:40px;
  --small-heading:24px;
  --small-size:14px;
  --edge:88px;
  --gutter:24px;
  --wrap-width:1280px;
  --head-height:72px;
  --anchor-offset:88px;
  --toc-offset:156px;
  --grid-size:48px;
  --space-1:8px;
  --space-2:16px;
  --space-3:24px;
  --space-4:32px;
  --space-5:40px;
  --space-6:48px;
  --space-8:64px;
  --space-10:80px;
  --shadow-card:inset 0 1px 0 var(--hi-edge),0 24px 48px -24px var(--accent-10);
  --shadow-button:inset 0 1px 0 var(--white-24),0 14px 28px -12px var(--accent-36);
  --ease: .2s ease;
}
*,*::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(--font-body);font-size:var(--body-size);line-height:var(--body-leading);-webkit-font-smoothing:antialiased}
img{max-width:100%;height:auto}
svg{flex-shrink:0}
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}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:var(--r-xs)}
[hidden]{display:none!important}
h1,h2,h3,h4,p,figure,blockquote{margin:0}
h1,h2,h3{font-family:var(--font-display);font-weight:var(--weight-normal);text-wrap:balance}
h1{font-size:clamp(52px,4.5vw,64px);line-height:1.12;letter-spacing:-.02em}
h2{font-size:var(--heading-size);line-height:1.25;letter-spacing:-.02em}
h3{font-size:var(--small-heading);line-height:1.4}
ul,ol{margin:0;padding:0;list-style:none}
code{font-family:var(--font-mono);font-size:.88em;overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:var(--space-3);background:var(--bg-panel-2);border-radius:var(--r-sm)}
pre code{overflow-wrap:normal;white-space:pre}
.no-break{white-space:nowrap}
.wrap{width:100%;max-width:var(--wrap-width);margin-inline:auto;padding-inline:var(--gutter)}
.sec{padding-top:var(--space-10);padding-bottom:var(--space-10)}
.stack>*+*{margin-top:var(--space-3)}
.grid{display:grid;gap:var(--space-3)}
.grid>*{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)}
.panel,.card{min-width:0;background:var(--bg-panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--shadow-card);padding:var(--space-4)}
.section-head{margin-bottom:var(--space-5);max-width:800px}
.section-head p{margin-top:var(--space-2);color:var(--text-muted)}
.prose{min-width:0;overflow-wrap:anywhere}
.prose p,.prose ul,.prose ol,.prose pre,.prose blockquote,.prose table{margin-block:var(--space-3)}
.prose h2{margin-top:var(--space-8);margin-bottom:var(--space-3)}
.prose h3{margin-top:var(--space-4);margin-bottom:var(--space-2)}
.prose ul{list-style:disc;padding-left:var(--space-3)}
.prose ol{list-style:decimal;padding-left:var(--space-3)}
.prose a{text-decoration:underline;text-underline-offset:4px;color:var(--accent-dark)}
.decor-region{position:relative;overflow-x:clip}
[data-parallax-decor]{pointer-events:none;max-width:100%}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;height:52px;padding:0 28px;border-radius:var(--r-pill);font-size:16px;font-weight:var(--weight-medium);line-height:1;white-space:nowrap;flex-shrink:0;border:1.5px solid var(--clear);transition:transform var(--ease),box-shadow var(--ease),background-color var(--ease)}
.btn svg{width:16px;height:16px;display:block}
.btn-solid,.btn-primary{color:var(--on-accent);background:linear-gradient(180deg,var(--accent) 0%,var(--accent) 55%,var(--accent-dark) 160%);box-shadow:var(--shadow-button)}
.btn-solid:hover,.btn-primary:hover{transform:translateY(-1px);box-shadow:inset 0 1px 0 var(--white-24),0 18px 32px -12px var(--accent-36)}
.btn-ghost,.btn-secondary{color:var(--accent-dark);background:var(--clear);border-color:var(--accent-dark)}
.btn-ghost:hover,.btn-secondary:hover{background:var(--white-40)}
.btn:disabled,.btn[aria-disabled="true"]{opacity:.5;pointer-events:none;transform:none}
.btn.is-focus{outline:2px solid var(--accent);outline-offset:3px}
.btn.is-hover{transform:translateY(-1px);box-shadow:var(--shadow-button)}
.cta-row{display:flex;flex-wrap:wrap;gap:16px;margin-top:32px}
.site-head{display:flex;align-items:center;gap:32px;height:var(--head-height);padding:0 var(--edge);position:relative;z-index:60;background:var(--bg)}
#site-header{position:relative;z-index:60;min-height:var(--head-height)}
.brand{display:inline-flex;align-items:center;gap:10px;flex:none;min-height:40px}
.brand-mark{width:30px;height:30px;display:block}
.brand-word{font-family:var(--font-display);font-size:20px;font-weight:var(--weight-bold);letter-spacing:-.02em;color:var(--text)}
.dotnav{flex:1;display:flex;justify-content:center;min-width:0}
.dotnav ul{display:flex;align-items:center;list-style:none;margin:0;padding:0;flex-wrap:nowrap}
.dotnav li{display:flex;align-items:center;white-space:nowrap}
.dotnav li+li::before{content:"·";color:var(--border);font-weight:var(--weight-bold);margin:0 12px}
.dotnav a{display:inline-flex;align-items:center;min-height:28px;font-size:14.5px;color:var(--text-muted);padding:4px 2px;transition:color var(--ease)}
.dotnav a:hover,.dotnav a[aria-current="page"]{color:var(--text)}
.dotnav a[aria-current="page"]{font-weight:var(--weight-medium)}
.head-tools{display:flex;align-items:center;gap:12px;flex-shrink:0;margin-left:auto}
.lang-picker{position:relative}
.lang-switch{display:inline-flex;align-items:center;justify-content:center;gap:6px;height:40px;min-width:44px;width:auto;padding:0 12px;border:0;background:var(--clear);cursor:pointer;font-size:14px;color:var(--text-muted);border-radius:var(--r-pill)}
.lang-switch span{white-space:nowrap}
.lang-switch:hover{color:var(--text)}
.lang-switch svg{width:16px;height:16px;display:block}
.lang-panel{position:absolute;right:0;top:calc(100% + 8px);z-index:80;min-width:180px;padding:8px;background:var(--bg-panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--shadow-card)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-xs);font-size:14px}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--bg-panel-2)}
.login-btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;height:40px;padding:0 18px 0 14px;border-radius:var(--r-pill);background:var(--bg-panel);border:1px solid var(--border);box-shadow:inset 0 1px 0 var(--hi-edge),0 6px 16px -8px var(--accent-24);font-size:14.5px;font-weight:var(--weight-medium);color:var(--text);white-space:nowrap;transition:border-color var(--ease)}
.login-btn:hover{border-color:var(--accent-dark)}
.login-btn svg{width:18px;height:18px;display:block}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;border:1px solid var(--border);border-radius:var(--r-sm);background:var(--bg-panel);color:var(--text)}
.menu-toggle svg{width:20px;height:20px;display:block}
.nav-drawer{display:none;position:fixed;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);z-index:58;padding:16px var(--gutter) 40px}
.nav-drawer a{display:flex;width:100%;min-height:44px;align-items:center;padding:12px 16px;border-bottom:1px solid var(--border);color:var(--text)}
.nav-drawer a[aria-current]{font-weight:var(--weight-medium);background:var(--bg-panel-2)}
.drawer-languages{margin-top:24px;border-top:1px solid var(--border)}
.nav-veil{display:none;position:fixed;inset:var(--head-height) 0 0;background:var(--veil);z-index:55}
html.nav-open{overflow:hidden}
.site-foot{margin-top:var(--space-8);background:var(--bg-panel-2);border-top:1px solid var(--border);padding-top:var(--space-8);padding-bottom:var(--space-4)}
.footer-grid{display:grid;grid-template-columns:1.25fr 1fr 1fr;gap:var(--space-6)}
.footer-brand p{max-width:360px;margin-top:var(--space-2);color:var(--text-muted);font-size:15px}
.footer-title{font-size:16px;font-weight:var(--weight-medium);margin-bottom:var(--space-2)}
.footer-links{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:4px 16px}
.footer-links a,.footer-languages a,.footer-legal a{display:inline-flex;align-items:center;min-height:28px;font-size:14px;color:var(--text-muted)}
.footer-links a:hover,.footer-languages a:hover,.footer-legal a:hover{color:var(--text)}
.footer-languages{display:flex;flex-wrap:wrap;gap:8px 24px;margin-top:var(--space-4)}
.footer-bottom{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px;margin-top:var(--space-4);padding-top:var(--space-3);border-top:1px solid var(--border);font-size:13px;color:var(--text-muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:20px}
.reveal{transition:opacity .35s ease,transform .35s ease}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
#server-status{display:block;position:relative;min-width:0;max-width:100%;overflow:hidden;margin-block:var(--space-4)}
#server-status+*{margin-top:var(--space-4)}
[data-counter]{display:inline-block;font-variant-numeric:tabular-nums;font-family:var(--font-mono);min-width:3ch;text-align:right}
@media(max-width:1280px){
  :root{--edge:64px}
  .dotnav li+li::before{margin:0 8px}
  .site-head{gap:20px}
}
@media(max-width:1100px){
  .site-head{gap:16px;padding-inline:var(--gutter)}
  .dotnav{display:none}
  .menu-toggle{display:inline-flex}
  html.nav-open .nav-drawer,html.nav-open .nav-veil{display:block}
  .head-tools{margin-left:auto}
}
@media(max-width:768px){
  :root{--edge:24px;--heading-size:32px}
  h1{font-size:40px}
  .grid-three,.grid-two,.footer-grid{grid-template-columns:1fr}
  .sec{padding-top:48px;padding-bottom:48px}
  .panel,.card{padding:24px}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  h1{font-size:36px}
  .lang-switch span{display:none}
  .head-tools{gap:6px;margin-left:auto}
  .lang-switch{padding-inline:8px}
  .site-head{flex-wrap:nowrap;gap:8px}
  .brand{gap:6px}
  .brand-word{font-size:18px}
  .brand-mark{width:26px;height:26px}
  .login-btn{padding-inline:12px;font-size:14px}
  .login-btn svg{display:none}
  .tilt,[data-tilt]{transform:none!important}
  [data-parallax-decor]{max-width:100%}
  .footer-links{gap:6px 16px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none;transition:none}
  .btn,.login-btn,.dotnav a{transition:none}
}