:root{
  color-scheme:light;
  --c-bg:#E9EDF7;
  --c-panel:#F8FAFE;
  --c-panel-2:#DCE2F0;
  --c-border:#CDD5E6;
  --c-accent:#171A2C;
  --c-accent-dark:#0B0D18;
  --c-text:#141827;
  --c-muted:#5B6478;
  --c-success:#1E9E6A;
  --c-warn:#E08A1E;
  --c-error:#D2453B;
  --c-white:#FFFFFF;
  --c-hero-top:#F3F6FC;
  --c-hero-bottom:#E2E8F4;
  --c-titlebar:#EEF1F8;
  --c-sidebar:#E3E8F3;
  --c-ice:#EDF2FC;
  --c-band:#E5EAF5;
  --c-line-soft:#E0E5F0;
  --c-idle:#A3ABBE;
  --c-faint:#848CA1;
  --c-periwinkle:#7C8BE0;
  --c-halo:rgba(124,139,224,.17);
  --c-mac-red:#EC6A5E;
  --c-mac-yellow:#F4BF4F;
  --c-mac-green:#61C554;
  --c-av-w:#6F86B6;
  --c-av-m:#7B77B0;
  --c-av-i:#5C97A3;
  --c-av-a:#7F95AB;
  --c-av-l:#8E88B2;
  --c-flag-red:#D7313B;
  --c-flag-blue:#2A3A7A;
  --c-ink-05:rgba(23,26,44,.05);
  --c-ink-07:rgba(23,26,44,.07);
  --c-ink-10:rgba(23,26,44,.10);
  --c-ink-12:rgba(23,26,44,.12);
  --c-ink-18:rgba(23,26,44,.18);
  --c-hi:rgba(255,255,255,.95);
  --c-hi-soft:rgba(255,255,255,.16);
  --c-on-dark-muted:rgba(255,255,255,.72);
  --c-success-soft:rgba(30,158,106,.11);
  --c-clear:transparent;
  --font-display:"Inter","Noto Sans SC",-apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif;
  --font-body:"Inter","Noto Sans SC",-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans","Microsoft YaHei",sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --fs-body:15px;
  --fs-small:13px;
  --fs-caption:12px;
  --fs-h1:clamp(52px,4.45vw,64px);
  --fs-h2:clamp(26px,3vw,36px);
  --fs-h3:22px;
  --fs-lead:19px;
  --weight-normal:400;
  --weight-medium:500;
  --weight-semibold:600;
  --weight-bold:700;
  --weight-display:800;
  --r-xs:6px;
  --r-sm:8px;
  --r-md:10px;
  --r-lg:12px;
  --r-pill:999px;
  --r-round:50%;
  --r-key:4px;
  --r-nav:7px;
  --r-chip:5px;
  --sh-window:0 2px 6px var(--c-ink-05),0 28px 60px var(--c-ink-10);
  --sh-raised:0 1px 2px var(--c-ink-05),0 10px 26px var(--c-ink-07);
  --sh-float:0 2px 6px var(--c-ink-05),0 16px 36px var(--c-ink-12);
  --sh-cta:0 1px 2px var(--c-ink-18),0 8px 20px var(--c-ink-12);
  --sh-fine:0 1px 2px var(--c-ink-05);
  --gutter:32px;
  --head-height:64px;
  --ann-height:40px;
  --drawer-top:104px;
  --toc-offset:12px;
  --chapter-offset:96px;
  --ease-out:cubic-bezier(.2,.7,.3,1);
  --time-fast:.15s;
  --time-reveal:.35s;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:80px}
body{margin:0;background:var(--c-bg);color:var(--c-text);font-family:var(--font-body);font-size:var(--fs-body);font-weight:var(--weight-normal);line-height:1.55;-webkit-font-smoothing:antialiased}
[hidden]{display:none!important}
img{display:block;max-width:100%;height:auto}
svg{flex-shrink:0;vertical-align:middle}
button,input,select,textarea{font:inherit;color:inherit}
button{cursor:pointer}
a{color:inherit;text-decoration:none}
a,button,summary{touch-action:manipulation}
button:disabled,.btn[aria-disabled="true"]{cursor:not-allowed;opacity:.55}
:where(a,button,input,select,textarea,summary,[tabindex]):focus-visible{outline:2px solid var(--c-periwinkle);outline-offset:3px}
ul{list-style:none;margin:0;padding:0}
p{margin:0}
h1,h2,h3,h4{font-family:var(--font-display);text-wrap:balance;overflow-wrap:break-word}
h1{margin:0;font-size:var(--fs-h1);font-weight:var(--weight-display);line-height:1.1;letter-spacing:-.02em}
h2{margin:0 0 20px;font-size:var(--fs-h2);font-weight:var(--weight-bold);line-height:1.2;letter-spacing:-.02em}
h3{margin:0 0 12px;font-size:var(--fs-h3);line-height:1.35;font-weight:var(--weight-bold)}
h4{font-size:var(--fs-body)}
strong{font-weight:var(--weight-semibold)}
code,kbd,pre,.mono{font-family:var(--font-mono)}
code{overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:20px;background:var(--c-panel-2);border:1px solid var(--c-border);border-radius:var(--r-sm);font-size:var(--fs-small)}
pre code{overflow-wrap:normal;white-space:pre}
hr{border:0;border-top:1px solid var(--c-border);margin:32px 0}
.wrap{width:100%;max-width:1264px;margin-inline:auto;padding-inline:var(--gutter)}
.wrap-wide{width:100%;max-width:1368px;margin-inline:auto;padding-inline:24px}
.section{padding-top:72px;padding-bottom:72px}
.section-head{max-width:780px;margin-bottom:32px}
.section-head p{color:var(--c-muted);font-size:var(--fs-lead)}
.grid{display:grid;gap:24px}
.grid-2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid-3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid-5{grid-template-columns:repeat(5,minmax(0,1fr))}
:where(.grid,.head-row,.footer-grid,.cta-row)>*{min-width:0}
.panel,.card{min-width:0;background:var(--c-panel);border:1px solid var(--c-border);border-radius:var(--r-lg);box-shadow:inset 0 1px 0 var(--c-hi),var(--sh-raised);padding:28px}
.panel-sunken{background:var(--c-panel-2);box-shadow:inset 0 1px 2px var(--c-ink-05)}
.muted{color:var(--c-muted)}
.small{font-size:var(--fs-small)}
.no-break{white-space:nowrap}
.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}
.svg-defs{position:absolute;width:0;height:0;overflow:hidden}
.ico{fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round;flex:none}
.ico-fill{fill:currentColor;flex:none}
.fill-white,.fl-white{fill:var(--c-white)}
.fl-red{fill:var(--c-flag-red)}
.fl-blue{fill:var(--c-flag-blue)}
.fl-edge{fill:none;stroke:var(--c-ink-18);stroke-width:1.2}
.flag{flex:none;display:block;overflow:hidden;border-radius:var(--r-key)}
.cta-row{display:flex;justify-content:center;gap:12px;margin-top:24px}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;padding:10px 24px;border:1px solid var(--c-clear);border-radius:var(--r-md);font-size:var(--fs-body);font-weight:var(--weight-semibold);line-height:24px;flex-shrink:0;white-space:nowrap;transition:transform var(--time-fast) var(--ease-out),box-shadow var(--time-fast) var(--ease-out)}
.btn:hover{transform:translateY(-1px)}
.btn:active{transform:translateY(0)}
.btn-ghost,.btn-secondary{background:var(--c-white);color:var(--c-accent);border-color:var(--c-accent)}
.btn-solid,.btn-primary{background:linear-gradient(180deg,var(--c-accent),var(--c-accent-dark));color:var(--c-white);border-color:var(--c-accent-dark);box-shadow:inset 0 1px 0 var(--c-hi-soft),var(--sh-cta)}
.btn:disabled:hover,.btn[aria-disabled="true"]:hover{transform:none}
.text-link{display:inline-flex;align-items:center;gap:6px;min-height:28px;text-decoration:underline;text-underline-offset:4px}
.prose{min-width:0;max-width:860px;line-height:1.85}
.prose p,.prose ul,.prose ol{margin:0 0 20px}
.prose ul{list-style:disc;padding-left:24px}
.prose ol{padding-left:24px}
.prose h2{margin-top:48px}
.prose h3{margin-top:28px}
.prose a{text-decoration:underline;text-underline-offset:3px}
.prose :where(img,figure){max-width:100%;margin-inline:0}
.reveal{transition:opacity var(--time-reveal) var(--ease-out),transform var(--time-reveal) var(--ease-out)}
.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%;min-height:120px;overflow:hidden;margin-block:24px}
#server-status+*{margin-top:24px}
#server-status :where(.grid,ul){min-width:0;max-width:100%}
#server-status :where(li,article,div){min-width:0}
.ann-check:checked+.ann{display:none}
.ann{position:relative;display:flex;align-items:center;justify-content:center;min-height:var(--ann-height);padding:0 56px;background:var(--c-accent);color:var(--c-white);font-size:13.5px;letter-spacing:.01em}
.ann-link{display:inline-flex;align-items:center;gap:8px;min-height:32px}
.ann-arrow{display:inline-block;transition:transform var(--time-fast) ease}
.ann-link:hover .ann-arrow{transform:translateX(3px)}
.ann-x{position:absolute;right:16px;top:50%;width:28px;height:28px;margin-top:-14px;display:grid;place-items:center;border:0;border-radius:var(--r-xs);background:var(--c-clear);color:var(--c-on-dark-muted);cursor:pointer}
.ann-x:hover{color:var(--c-white);background:var(--c-hi-soft)}
.ann-check:focus-visible+.ann .ann-x{outline:2px solid var(--c-white);outline-offset:1px}
html:has(.ann-check:checked){--drawer-top:64px}
.site-head{position:relative;z-index:102;background:var(--c-hero-top);border-bottom:1px solid var(--c-line-soft)}
.head-row{height:var(--head-height);display:flex;align-items:center;gap:44px;flex-wrap:nowrap}
.brand{display:inline-flex;align-items:center;gap:9px;flex-shrink:0;font-family:var(--font-display);font-weight:var(--weight-display);font-size:19px;letter-spacing:-.02em;color:var(--c-text);min-height:32px}
.brand img{width:26px;height:26px;flex-shrink:0}
.site-nav{flex:1;min-width:0}
.nav-links{display:flex;align-items:center;list-style:none;margin:0;padding:0}
.nav-links li{display:flex;align-items:center;flex-shrink:0}
.nav-links li+li::before{content:"·";color:var(--c-idle);margin:0 12px;font-weight:var(--weight-bold)}
.nav-links a{font-size:14.5px;color:var(--c-muted);padding:6px 2px;border-radius:var(--r-xs);transition:color var(--time-fast) ease}
.nav-links a:hover{color:var(--c-text)}
.nav-links a.is-active{color:var(--c-accent);font-weight:var(--weight-semibold)}
.head-tools{margin-left:auto;display:flex;align-items:center;gap:10px;flex-shrink:0}
.lang-wrap{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;height:36px;padding:0 12px;border:1px solid var(--c-clear);border-radius:var(--r-md);background:var(--c-clear);font-size:14px;color:var(--c-muted);cursor:pointer}
.lang-text{white-space:nowrap}
.lang:hover{border-color:var(--c-border);background:var(--c-panel);color:var(--c-text)}
.lang-menu{position:absolute;right:0;top:calc(100% + 10px);z-index:120;width:184px;padding:6px;border:1px solid var(--c-border);border-radius:var(--r-md);background:var(--c-panel);box-shadow:var(--sh-float)}
.lang-menu a{display:flex;align-items:center;min-height:40px;padding:8px 12px;border-radius:var(--r-xs);white-space:nowrap}
.lang-menu a:hover,.lang-menu a[aria-current]{background:var(--c-panel-2)}
.btn-login{display:inline-flex;align-items:center;justify-content:center;height:36px;min-width:64px;padding:0 18px;border:1px solid var(--c-border);border-radius:var(--r-md);background:var(--c-white);color:var(--c-accent);font-size:14px;font-weight:var(--weight-semibold);white-space:nowrap;box-shadow:var(--sh-fine);transition:border-color var(--time-fast) ease}
.btn-login:hover{border-color:var(--c-accent)}
.menu-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;border:1px solid var(--c-border);border-radius:var(--r-sm);background:var(--c-panel);color:var(--c-accent)}
.menu-line{display:block;width:20px;height:2px;background:currentColor}
.nav-drawer{position:fixed;top:var(--drawer-top);right:0;left:0;z-index:101;height:calc(100dvh - var(--drawer-top));max-height:calc(100dvh - var(--drawer-top));overflow-y:auto;overscroll-behavior:contain;padding:20px var(--gutter) 40px;background:var(--c-panel);border-top:1px solid var(--c-border)}
.nav-drawer a{display:flex;align-items:center;width:100%;min-height:46px;padding:12px 14px;border-radius:var(--r-sm)}
.nav-drawer a:hover,.nav-drawer a[aria-current]{background:var(--c-panel-2)}
.drawer-languages{display:grid;gap:4px;border-top:1px solid var(--c-border);margin-top:16px;padding-top:16px}
.nav-veil{position:fixed;inset:var(--drawer-top) 0 0;z-index:100;background:var(--c-ink-18);border:0}
html.nav-open{overflow:hidden}
.site-footer{background:var(--c-panel-2);border-top:1px solid var(--c-border);padding-top:48px;padding-bottom:32px}
.footer-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:48px}
.footer-intro{max-width:350px;margin-top:16px;color:var(--c-muted)}
.footer-title{margin:0 0 12px;font-size:var(--fs-body);font-weight:var(--weight-semibold)}
.footer-links{display:grid;gap:4px}
.footer-links a,.footer-languages a,.footer-legal a{display:inline-flex;align-items:center;min-height:28px;padding-block:3px}
.footer-links a:hover,.footer-legal a:hover{text-decoration:underline;text-underline-offset:4px}
.footer-languages{display:flex;flex-wrap:wrap;gap:8px 20px;margin-top:32px}
.footer-languages [aria-current]{font-weight:var(--weight-bold)}
.footer-bottom{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px;border-top:1px solid var(--c-border);margin-top:24px;padding-top:20px;font-size:var(--fs-small);color:var(--c-muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:8px 20px}
@media(min-width:901px){.nav-drawer,.nav-veil{display:none!important}}
@media(max-width:1200px){
  .head-row{gap:24px}
  .nav-links li+li::before{margin:0 8px}
  .nav-links a{font-size:var(--fs-small)}
}
@media(max-width:1024px){.head-row{gap:20px}.head-tools{gap:6px}}
@media(max-width:900px){
  .site-nav{display:none}
  .menu-toggle{display:flex}
  .head-tools{margin-left:auto}
  .footer-grid{gap:28px;grid-template-columns:1fr 1fr}
  .footer-grid>div:first-child{grid-column:1/-1}
  .grid-5{grid-template-columns:repeat(3,minmax(0,1fr))}
}
@media(max-width:768px){
  :root{--fs-h1:36px;--fs-lead:17px}
  .grid-3{grid-template-columns:1fr}
  .section{padding-top:48px;padding-bottom:48px}
  .lang-text{display:none}
  .cta-row{flex-wrap:wrap}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .wrap,.wrap-wide{width:100%;padding-inline:var(--gutter)}
  .grid-2,.grid-5{grid-template-columns:1fr}
  .head-row{gap:8px}
  .head-tools{gap:4px;margin-left:auto}
  .brand{font-size:17px;gap:6px}
  .brand img{width:24px;height:24px}
  .btn-login{min-width:52px;padding-inline:12px}
  .lang{padding-inline:8px}
  .ann{font-size:12.5px;padding:0 44px 0 16px}
  .panel,.card{padding:20px}
  .footer-grid{grid-template-columns:1fr;gap:24px}
  .footer-grid>div:first-child{grid-column:auto}
  .tilt,.decor-tilt{transform:none!important}
  [data-hero-visual],.decoration-zone{max-width:100%;overflow-x:clip}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{transition:none!important;animation:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}