:root {
  --bg:#E3EBEF;--bg-top:#EEF4F6;--bg-bottom:#DCE6EB;--panel:#F6FAFB;--panel-2:#D4E0E5;--paper:#FFFFFF;
  --border:#C3D2D9;--border-soft:#D9E3E8;--accent:#B8402A;--accent-dark:#8C2C1B;--text:#12202A;--muted:#4D606C;--faint:#768A96;
  --ink:#13232C;--ink-2:#1D3441;--steel:#5E7D8C;--steel-mid:#87A1AD;--steel-light:#A9BDC7;
  --success:#1F8A5B;--warn:#B7791F;--error:#C21F4A;
  --on-ink:#E8F0F3;--on-ink-muted:rgba(232,240,243,.66);--on-ink-line:rgba(232,240,243,.22);
  --accent-0:rgba(184,64,42,0);--accent-06:rgba(184,64,42,.06);--accent-10:rgba(184,64,42,.10);--accent-12:rgba(184,64,42,.12);--accent-18:rgba(184,64,42,.18);--accent-35:rgba(184,64,42,.35);
  --steel-08:rgba(36,66,82,.08);--steel-14:rgba(36,66,82,.14);--steel-22:rgba(36,66,82,.22);
  --hl:rgba(255,255,255,.92);--hl-soft:rgba(255,255,255,.3);--success-ring:rgba(31,138,91,.18);
  --trace:rgba(19,35,44,.075);--trace-dim:rgba(19,35,44,.035);--trace-fill:rgba(19,35,44,.04);--trace-stub:rgba(19,35,44,.16);
  --flag-red:#D23A40;--flag-white:#FFFFFF;--flag-navy:#2D4373;--flag-green:#22894F;--flag-edge:rgba(19,35,44,.16);
  --veil:rgba(19,35,44,.42);--clear:transparent;
  --f-display:"Inter","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --f-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Microsoft YaHei",system-ui,sans-serif;
  --f-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --r-xs:4px;--r-sm:6px;--r-md:10px;--r-lg:14px;--r-xl:18px;--r-pill:999px;--r-round:50%;--r-pad:2px;
  --wrap:1200px;--gutter:24px;--head-height:76px;--toc-offset:96px;
  --shadow-panel:inset 0 0 0 1px var(--hl),0 30px 64px -30px var(--accent-10);
  --ease:cubic-bezier(.2,.7,.3,1);
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-padding-top:92px;scroll-behavior:smooth}
body{margin:0;font-family:var(--f-body);font-size:16px;line-height:1.6;color:var(--text);background:var(--bg-bottom);-webkit-font-smoothing:antialiased}
img,svg{vertical-align:middle}
img{max-width:100%;height:auto}
button,input,select,textarea{font:inherit;color:inherit}
button,summary{cursor:pointer}
button{border:0}
a{color:inherit;text-underline-offset:3px}
:where(a,button,summary,input,select,textarea,[tabindex]):focus-visible{outline:2px solid var(--accent);outline-offset:3px}
[hidden]{display:none!important}
h1,h2,h3{font-family:var(--f-display);text-wrap:balance;overflow-wrap:break-word}
h1{margin:0 0 24px;font-weight:900;font-size:clamp(52px,5vw,68px);line-height:1.1;letter-spacing:-.02em;color:var(--text)}
h2{margin:0 0 20px;font-size:36px;font-weight:800;line-height:1.25;letter-spacing:-.02em}
h3{margin:0 0 12px;font-size:23px;line-height:1.35}
p{margin:0 0 20px}
code{font-family:var(--f-mono);overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:20px;background:var(--panel-2);border:1px solid var(--border);border-radius:var(--r-sm)}
pre code{white-space:pre;overflow-wrap:normal}
:where(.grid,.cards-grid,.footer-grid)>*{min-width:0}
.no-break{white-space:nowrap}
.wrap{width:100%;max-width:calc(var(--wrap) + var(--gutter)*2);margin-inline:auto;padding-inline:var(--gutter)}
.sec{padding-top:80px;padding-bottom:80px}
.reading-wrap{max-width:880px;margin-inline:auto;padding-inline:var(--gutter)}
.prose{overflow-wrap:anywhere}
.prose p,.prose li{line-height:1.85}
.prose h2{margin-top:48px}
.prose h3{margin-top:32px}
.prose a{font-weight:600}
.prose img{border-radius:var(--r-md)}
.prose ol,.prose ul{padding-left:1.5em}
.muted{color:var(--muted)}
.mono-lab{font-family:var(--f-mono);font-size:11px;font-weight:500;letter-spacing:.12em;text-transform:uppercase;color:var(--text)}
.kw{color:var(--accent)}
.card,.panel{padding:24px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:var(--shadow-panel)}
.panel-inset{padding:20px;background:var(--panel-2);border:1px solid var(--border);border-radius:var(--r-sm);box-shadow:inset 0 2px 8px var(--steel-08)}
.cards-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:24px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:48px;padding:0 26px;border-radius:var(--r-sm);font-size:16px;font-weight:700;text-decoration:none;white-space:nowrap;flex-shrink:0;transition:transform .18s var(--ease),box-shadow .18s var(--ease)}
.btn:hover{transform:translateY(-1px)}
.btn:active,.btn.is-active{transform:translateY(1px)}
.btn-primary{color:var(--paper);background:linear-gradient(180deg,var(--accent),var(--accent-dark));box-shadow:inset 0 1px 0 var(--hl-soft),0 0 0 1px var(--accent-dark),0 16px 30px -14px var(--accent-35)}
.btn-primary span{font-size:11px;opacity:.8}
.btn-ghost,.btn-secondary{color:var(--text);background:var(--paper);border:1px solid var(--border);box-shadow:inset 0 1px 0 var(--hl),0 6px 14px -8px var(--steel-14)}
.btn:disabled,.btn[aria-disabled="true"]{opacity:.5;cursor:not-allowed;transform:none}
.btn.is-hover{transform:translateY(-1px);box-shadow:inset 0 1px 0 var(--hl-soft),0 0 0 1px var(--accent-dark),0 18px 34px -12px var(--accent-35)}
.btn.is-focus{outline:2px solid var(--accent);outline-offset:3px}
.btn-ink{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:28px;padding:0 12px;border-radius:var(--r-xs);background:var(--ink);color:var(--on-ink);font-size:12.5px;font-weight:600;text-decoration:none;box-shadow:inset 0 1px 0 var(--hl-soft),0 6px 12px -8px var(--steel-22)}
.btn-ink span{font-size:9px;color:var(--on-ink-muted)}
.ann{position:relative;z-index:6;display:flex;justify-content:center;align-items:stretch;min-height:36px;background:var(--ink)}
.ann-tab{display:flex;align-items:center;gap:14px;padding:0 46px;background:var(--ink-2);clip-path:polygon(0 0,100% 0,calc(100% - 22px) 100%,22px 100%);font-size:13px;color:var(--on-ink)}
.ann-sep{width:1px;height:14px;flex-shrink:0;background:var(--on-ink-line)}
.ann-link{display:inline-flex;align-items:center;gap:6px;min-height:24px;color:var(--on-ink);text-decoration:none;font-weight:600;white-space:nowrap}
.ann-link span{font-size:10px;color:var(--on-ink-muted)}
.ann-link:hover{text-decoration:underline}
.topnav{position:relative;z-index:50;padding:12px 24px 0}
.nav-shell{position:relative;max-width:var(--wrap);margin:0 auto;min-height:52px;display:flex;align-items:center;gap:28px;padding:0 10px 0 14px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:inset 0 1px 0 var(--hl),0 10px 24px -14px var(--steel-22)}
.brand{display:flex;align-items:center;gap:10px;flex:none;min-height:34px;text-decoration:none}
.brand img{display:block;width:28px;height:28px}
.brand-en{font-family:var(--f-display);font-weight:800;font-size:18px;letter-spacing:-.02em;color:var(--text)}
.nav-dots{flex:1;min-width:0}
.nav-dots ul{display:flex;align-items:center;list-style:none;margin:0;padding:0;white-space:nowrap}
.nav-dots li{display:flex;align-items:center;font-size:14px}
.nav-dots li+li::before{content:"·";margin:0 11px;color:var(--steel-light);font-weight:700}
.nav-dots a{display:inline-flex;align-items:center;min-height:32px;color:var(--muted);text-decoration:none}
.nav-dots a:hover{color:var(--text)}
.nav-dots a[aria-current="page"]{color:var(--text);font-weight:600}
.nav-dots>ul>li{flex-shrink:0}
.nav-more{position:relative}
.nav-more-toggle{min-height:32px;padding:0 8px;color:var(--muted);white-space:nowrap}
.nav-dots .nav-more-panel{position:absolute;top:calc(100% + 10px);right:0;z-index:70;display:block;min-width:220px;max-width:calc(100vw - 48px);padding:6px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:0 16px 32px var(--steel-14);white-space:normal}
.nav-dots .nav-more-panel li{display:block}
.nav-dots .nav-more-panel li::before{content:none}
.nav-dots .nav-more-panel a{display:flex;min-height:44px;padding:8px 12px;border-radius:var(--r-sm)}
.nav-more-panel a:hover{background:var(--panel-2)}
.nav-end{display:flex;align-items:center;gap:6px;margin-left:auto;flex-shrink:0}
.lang-wrap{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;min-height:34px;padding:0 12px;border:0;border-radius:var(--r-sm);background:var(--clear);font:inherit;font-size:13.5px;color:var(--muted);cursor:pointer;white-space:nowrap}
.lang span{white-space:nowrap}
.lang:hover{color:var(--text)}
.lang-panel{position:absolute;right:0;top:calc(100% + 10px);z-index:80;width:180px;padding:6px;background:var(--panel);border:1px solid var(--border);border-radius:var(--r-md);box-shadow:0 16px 32px var(--steel-14)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;text-decoration:none;border-radius:var(--r-sm)}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--panel-2)}
.btn-login{display:inline-flex;align-items:center;justify-content:center;min-height:34px;padding:0 18px;border-radius:var(--r-sm);background:var(--ink);color:var(--on-ink);font-size:14px;font-weight:600;text-decoration:none;white-space:nowrap;box-shadow:inset 0 1px 0 var(--hl-soft),0 6px 14px -8px var(--steel-22);transition:transform .18s var(--ease)}
.btn-login:hover{transform:translateY(-1px)}
.menu-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;padding:8px;border-radius:var(--r-sm);background:var(--panel-2);color:var(--ink)}
.menu-line{display:block;width:20px;height:2px;background:currentColor}
.nav-drawer{position:fixed;z-index:45;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(--panel);overflow-y:auto;overscroll-behavior:contain;border-top:1px solid var(--border)}
.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 14px;text-decoration:none;border-bottom:1px solid var(--border-soft)}
.nav-drawer a[aria-current]{font-weight:700;background:var(--panel-2)}
.drawer-languages{margin-top:20px;border-top:1px solid var(--border)}
.nav-veil{position:fixed;z-index:40;inset:var(--head-height) 0 0;background:var(--veil);border:0}
html.nav-open{overflow:hidden}
#site-header{position:relative;z-index:50}
.site-footer{padding-top:56px;padding-bottom:32px;background:var(--panel-2);border-top:1px solid var(--border);box-shadow:inset 0 1px 0 var(--hl)}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr;gap:48px}
.footer-brand p{max-width:320px;margin-top:16px;color:var(--muted)}
.footer-title{font-size:14px;font-weight:700;margin:0 0 12px}
.footer-links{display:flex;flex-wrap:wrap;gap:4px 18px;list-style:none;padding:0;margin:0}
.footer-links a{display:inline-flex;align-items:center;min-height:32px;font-size:14px;text-decoration:none;color:var(--muted)}
.footer-links a:hover{text-decoration:underline;color:var(--text)}
.footer-languages{display:flex;flex-wrap:wrap;gap:6px 20px;margin-top:32px;padding-top:20px;border-top:1px solid var(--border)}
.footer-languages a{display:inline-flex;align-items:center;min-height:32px;font-size:14px}
.footer-bottom{display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;margin-top:24px;font-size:13px;color:var(--muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:20px}
.footer-legal a{display:inline-flex;align-items:center;min-height:24px}
.reveal{transition:opacity .35s var(--ease),transform .35s var(--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%;overflow:hidden;margin-top:24px;margin-bottom:32px}
#server-status>*{min-width:0;max-width:100%}
#server-status+*{margin-top:32px}
.decor-section{position:relative;overflow-x:clip}
@media(max-width:1180px){
 .nav-shell{gap:20px}.nav-dots li{font-size:13px}.nav-dots li+li::before{margin:0 8px}
}
@media(max-width:1080px){
 .nav-shell{gap:12px}.nav-dots li+li::before{margin:0 5px}.lang{padding-inline:8px}
}
@media(max-width:980px){
 .topnav{padding:10px 14px 0}.nav-shell{min-height:56px;gap:8px;flex-wrap:nowrap}
 .nav-dots{display:none}.nav-end{margin-left:auto}.menu-toggle{display:inline-flex}
 .footer-grid{grid-template-columns:1fr 1fr;gap:32px}.footer-brand{grid-column:1/-1}
 h1{font-size:54px}
 .preview-nav .nav-shell{flex-wrap:wrap;padding-top:8px;padding-bottom:8px}
 .preview-nav .nav-dots{display:block;order:3;flex-basis:100%;overflow-x:auto}
}
@media(min-width:981px){.nav-drawer,.nav-veil{display:none}}
@media(max-width:768px){
 :root{--gutter:16px}
 h1{font-size:38px;margin-bottom:20px}h2{font-size:30px}
 .sec{padding-top:56px;padding-bottom:56px}
 .cards-grid{grid-template-columns:1fr}
 .ann-tab{padding:4px 22px;font-size:12px;gap:10px;flex-wrap:wrap;justify-content:center}
 .ann-sep{display:none}
}
@media(max-width:640px){
 .no-break{white-space:normal}
 .tilt{transform:none}
 .decor-section>*[aria-hidden="true"]{max-width:100%}
 .nav-shell{padding-inline:9px}
 .brand{gap:6px}.brand-en{font-size:16px}.brand img{width:24px;height:24px}
 .nav-end{gap:3px;margin-left:auto}.btn-login{padding-inline:11px;font-size:13px}
 .lang{font-size:12px;padding-inline:5px;gap:3px}.menu-toggle{min-width:44px}
 .footer-grid{grid-template-columns:1fr}
 .footer-brand{grid-column:auto}
}
@media(max-width:359px){
 .brand-en{font-size:14px}.brand{gap:4px}.nav-shell{gap:3px;padding-inline:6px}.lang{font-size:11px}.btn-login{padding-inline:8px}
}
@media(prefers-reduced-motion:reduce){
 html{scroll-behavior:auto}
 .reveal,.reveal.pending,.reveal.shown{opacity:1;transform:none;transition:none}
 .btn,.btn-login{transition:none}
}