:root{
  --bg:#F6F6F3;--panel:#FFFFFF;--panel-2:#ECEEF4;--border:#E0E0DA;
  --accent:#17306E;--accent-dark:#0E1F4B;--cobalt:#3E5BC4;--poppy:#D9481F;
  --text:#161A24;--muted:#5A5F6C;--success:#1E8A5A;--warn:#C4870C;--error:#C5372C;
  --hero-top:#E8ECF7;--bar-top:#F7F8FB;--line-soft:#E5E8EF;--tile-edge:#DCE0EA;--dot:#D2D7E4;--success-tint:#E6F3EC;
  --navy-04:rgba(23,48,110,.04);--navy-06:rgba(23,48,110,.06);--navy-08:rgba(23,48,110,.08);--navy-12:rgba(23,48,110,.12);--navy-16:rgba(23,48,110,.16);--navy-24:rgba(23,48,110,.24);
  --ribbon-lo:rgba(14,31,75,.42);--success-ring:rgba(30,138,90,.18);--poppy-glow:rgba(217,72,31,.08);--poppy-tint:rgba(217,72,31,.09);
  --white-hi:rgba(255,255,255,.95);--white-60:rgba(255,255,255,.6);--white-40:rgba(255,255,255,.4);--white-18:rgba(255,255,255,.18);--white-0:rgba(255,255,255,0);
  --on-dark:#FFFFFF;--on-dark-muted:rgba(255,255,255,.74);--on-dark-line:rgba(255,255,255,.22);
  --flag-red:#D33A3F;--flag-white:#FFFFFF;--flag-blue:#22397E;--flag-edge:rgba(22,26,36,.16);
  --veil:rgba(14,31,75,.42);
  --font-display:"Inter","Noto Sans SC","PingFang SC","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;
  --r-pill:999px;--r-panel:32px;--r-card:24px;--r-mini:16px;--r-tile:12px;--r-small:8px;--r-round:50%;
  --wrap:1312px;--wrap-wide:1392px;--reading:820px;--gutter:24px;--header-height:64px;--anchor-offset:80px;--toc-offset:148px;
  --size-body:16px;--size-small:14px;--size-h1:66px;--size-h2:36px;--size-h3:24px;
  --shadow-card:0 24px 64px -24px var(--navy-12),inset 0 1px 0 var(--white-hi);
  --ease:cubic-bezier(.2,.7,.3,1);--fast:.2s;--reveal-time:.35s;
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-padding-top:var(--anchor-offset);scroll-behavior:smooth}
html,body{margin:0}
body{background:var(--bg);color:var(--text);font-family:var(--font-body);font-size:var(--size-body);line-height:1.6;-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;padding-bottom:48px;overflow-x:clip}
img{display:block;max-width:100%;height:auto}
svg{flex-shrink:0}
button,input,select,textarea{font:inherit}
button{cursor:pointer}
button,a,summary{-webkit-tap-highlight-color:var(--navy-08)}
button{color:inherit}
a{color:inherit;text-underline-offset:4px}
:focus-visible{outline:2px solid var(--cobalt);outline-offset:3px}
[hidden]{display:none!important}
h1,h2,h3{font-family:var(--font-display);font-weight:800;text-wrap:balance;overflow-wrap:break-word}
h1{font-size:clamp(52px,5vw,var(--size-h1));line-height:1.12;letter-spacing:-.02em}
h2{font-size:var(--size-h2);line-height:1.25;letter-spacing:-.02em}
h3{font-size:var(--size-h3);line-height:1.35}
p{margin:0 0 1.25em}
code{font-family:var(--font-mono);font-size:.9em;overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;background:var(--panel-2);padding:24px;border-radius:var(--r-mini)}
pre code{white-space:pre;overflow-wrap:normal}
main,article,section,nav,aside,footer,header,div,li{min-width:0}
section[id]{scroll-margin-top:var(--anchor-offset)}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.no-break{white-space:nowrap}
.wrap,.wrap-wide,.reading-wrap{width:100%;padding-inline:var(--gutter);margin-inline:auto}
.wrap{max-width:calc(var(--wrap) + 2 * var(--gutter))}
.wrap-wide{max-width:calc(var(--wrap-wide) + 2 * var(--gutter))}
.reading-wrap{max-width:calc(var(--reading) + 2 * var(--gutter))}
.section{padding-top:64px;padding-bottom:64px}
.section-heading{margin:0 0 28px}
.muted{color:var(--muted)}
.mono{font-family:var(--font-mono)}
.card,.panel{padding:28px;background:var(--panel);border:1px solid var(--line-soft);border-radius:var(--r-card);box-shadow:var(--shadow-card)}
.panel{background:var(--panel-2)}
.card-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.prose{line-height:1.85;overflow-wrap:break-word}
.prose h2{margin-top:2em}
.prose h3{margin-top:1.6em}
.prose li+li{margin-top:8px}
.prose a{color:var(--accent)}
.prose img{border-radius:var(--r-mini)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:48px;padding:0 28px;border:1px solid transparent;border-radius:var(--r-pill);font-size:16px;font-family:var(--font-body);font-weight:700;line-height:1.3;text-decoration:none;white-space:nowrap;flex-shrink:0;transition:transform var(--fast) var(--ease),background-color var(--fast),box-shadow var(--fast)}
.btn svg{width:16px;height:16px}
.btn-solid,.btn-primary{background:linear-gradient(180deg,var(--accent),var(--accent-dark));color:var(--on-dark);box-shadow:inset 0 1px 0 var(--white-18),0 12px 24px -8px var(--navy-24)}
.btn-solid:hover,.btn-primary:hover{transform:translateY(-1px);box-shadow:inset 0 1px 0 var(--white-18),0 16px 28px -8px var(--navy-24)}
.btn-line,.btn-secondary{color:var(--accent);border-color:var(--accent);background:transparent}
.btn-line:hover,.btn-secondary:hover{background:var(--navy-06)}
.btn:active{transform:translateY(0)}
.btn:disabled,.btn[aria-disabled="true"]{opacity:.5;cursor:not-allowed;transform:none}
.cta-row{display:flex;flex-wrap:wrap;justify-content:center;gap:12px;margin-top:24px}
.site-header,#site-header{height:var(--header-height);position:relative;z-index:60}
.site-header .wrap{display:flex;align-items:center;gap:24px;height:100%;flex-wrap:nowrap}
.brand{display:inline-flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);font-family:var(--font-display);font-weight:800;font-size:20px;letter-spacing:-.02em;flex:none;min-height:38px}
.brand img{width:28px;height:28px;flex:none}
.brand-tie{color:var(--accent)}
.brand-zh{font-size:var(--size-small);font-weight:500;color:var(--muted)}
.nav{flex:1;display:flex;justify-content:center;min-width:0}
.nav-list{display:flex;align-items:center;gap:2px;list-style:none;margin:0;padding:0}
.nav-link{display:inline-flex;align-items:center;gap:7px;min-height:38px;padding:0 13px;border-radius:var(--r-pill);color:var(--muted);font-size:14.5px;font-weight:500;text-decoration:none;white-space:nowrap;transition:color var(--fast),background-color var(--fast)}
.nav-link:hover{color:var(--text);background:var(--navy-06)}
.nav-link[aria-current="page"]{color:var(--accent);background:var(--panel);box-shadow:0 0 0 1px var(--line-soft),0 2px 6px -2px var(--navy-12);font-weight:600}
.nav-ico{width:16px;height:16px;flex:none}
.header-tools{display:flex;align-items:center;gap:12px;flex-shrink:0}
.lang-picker{position:relative}
.lang-btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:38px;min-width:44px;width:auto;padding:0 12px;border:0;border-radius:var(--r-pill);background:transparent;color:var(--text);font:500 14px/1 var(--font-body)}
.lang-btn span{white-space:nowrap}
.lang-btn:hover{background:var(--navy-06)}
.lang-btn svg{width:16px;height:16px;color:var(--muted)}
.lang-caret{color:var(--muted);font-size:11px}
.lang-panel{position:absolute;right:0;top:calc(100% + 8px);z-index:90;min-width:180px;padding:8px;background:var(--panel);border:1px solid var(--line-soft);border-radius:var(--r-mini);box-shadow:var(--shadow-card)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;text-decoration:none;border-radius:var(--r-small)}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--navy-06);color:var(--accent)}
.tools-sep{width:1px;height:20px;background:var(--border);flex:none}
.login-btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:38px;padding:0 18px;border-radius:var(--r-pill);background:var(--accent);color:var(--on-dark);font-size:14px;font-weight:600;text-decoration:none;white-space:nowrap;box-shadow:inset 0 1px 0 var(--white-18),0 6px 14px -6px var(--navy-24);transition:background-color var(--fast)}
.login-btn:hover{background:var(--accent-dark)}
.login-btn svg{width:16px;height:16px}
.menu-btn{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;border:1px solid var(--line-soft);border-radius:var(--r-pill);background:var(--panel);color:var(--accent)}
.menu-btn svg{width:20px;height:20px}
.mobile-drawer{display:none}
.menu-veil{display:none}
html.nav-open{overflow:hidden}
.site-footer{padding-top:64px;padding-bottom:32px;border-top:1px solid var(--border);background:linear-gradient(180deg,var(--navy-04),var(--bg))}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr 1fr;gap:40px}
.footer-brand p{margin-top:18px;max-width:30em;color:var(--muted);font-size:var(--size-small)}
.footer-title{font-size:var(--size-small);margin:0 0 14px;color:var(--accent);font-weight:700}
.footer-links{display:grid;gap:5px;list-style:none;padding:0;margin:0}
.footer-links a{display:inline-flex;align-items:center;min-height:30px;text-decoration:none;font-size:var(--size-small);color:var(--muted)}
.footer-links a:hover{color:var(--accent);text-decoration:underline}
.footer-bottom{display:flex;align-items:center;flex-wrap:wrap;gap:12px 24px;margin-top:40px;padding-top:24px;border-top:1px solid var(--border);font-size:13px;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:relative;display:block;min-height:120px;max-width:100%;overflow:hidden;margin-top:24px;margin-bottom:24px}
#server-status+*{margin-top:24px}
#server-status>*{min-width:0;max-width:100%}
.decoration-zone{position:relative;overflow-x:clip;max-width:100%}
[data-counter]{display:inline-block;font-family:var(--font-mono);font-variant-numeric:tabular-nums;min-width:3ch;text-align:right}
.s-acc{stop-color:var(--accent)}
.s-cob{stop-color:var(--cobalt)}
.s-dk{stop-color:var(--accent-dark)}
.s-w{stop-color:var(--panel)}
.s-tint{stop-color:var(--panel-2)}
@media(min-width:1101px) and (max-width:1350px){
  .site-header .wrap{gap:14px}.nav-link{padding-inline:9px;gap:5px;font-size:13px}.header-tools{gap:8px}
}
@media(max-width:1100px){
  .nav{display:none}
  .header-tools{margin-left:auto}
  .menu-btn{display:inline-flex}
  .mobile-drawer{display:block;position:fixed;top:var(--header-height);right:0;width:min(440px,100%);height:calc(100dvh - var(--header-height));max-height:calc(100dvh - var(--header-height));overflow-y:auto;overscroll-behavior:contain;padding:20px var(--gutter) 40px;background:var(--panel);z-index:58;border-top:1px solid var(--line-soft)}
  .mobile-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:12px 16px;text-decoration:none;border-radius:var(--r-tile)}
  .mobile-drawer a:hover,.mobile-drawer a[aria-current]{background:var(--navy-06);color:var(--accent)}
  .mobile-drawer ul{display:grid;list-style:none;margin:0;padding:0;gap:4px}
  .drawer-languages{margin-top:24px;padding-top:16px;border-top:1px solid var(--border)}
  .menu-veil{display:block;position:fixed;inset:var(--header-height) 0 0;z-index:57;background:var(--veil);border:0;width:100%}
}
@media(max-width:768px){
  :root{--size-h1:38px;--size-h2:28px;--size-h3:21px}
  h1{font-size:clamp(28px,7vw,38px)}
  .section{padding-top:40px;padding-bottom:40px}
  .card-grid{grid-template-columns:minmax(0,1fr)}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:28px}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .tilt,[data-tilt]{transform:none}
  .decoration-zone{max-width:100%}
  .site-header .wrap{gap:8px}
  .brand{font-size:18px;gap:6px}
  .brand img{width:25px;height:25px}
  .header-tools{gap:4px;margin-left:auto}
  .lang-text,.lang-caret,.tools-sep{display:none}
  .lang-btn{padding-inline:8px}
  .login-btn{padding-inline:12px}
  .login-btn svg{display:none}
  .card,.panel{padding:20px}
  .footer-grid{grid-template-columns:minmax(0,1fr)}
  .btn{padding-inline:24px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none;transition:none}
  .btn,.nav-link,.login-btn{transition:none}
  .btn:hover{transform:none}
}