:root{
  color-scheme:light;
  --bg:#F5EEE4;--bg-top:#FBF6EE;--bg-bottom:#F1E7D8;
  --panel:#FFFBF5;--panel-2:#EFE5D6;--line:#E3D6C3;--line-strong:#D3C2AB;
  --accent:#6A3BD8;--accent-dark:#4E26AE;--accent-light:#9C7CF0;
  --accent-a04:rgba(106,59,216,.04);--accent-a06:rgba(106,59,216,.06);--accent-a10:rgba(106,59,216,.10);--accent-a12:rgba(106,59,216,.12);--accent-a18:rgba(106,59,216,.18);--accent-a35:rgba(106,59,216,.35);
  --berry:#E2407E;--berry-a40:rgba(226,64,126,.40);
  --ink:#2A1F17;--ink-muted:#6E6052;--ink-a04:rgba(42,31,23,.04);--ink-a08:rgba(42,31,23,.08);--ink-a14:rgba(42,31,23,.14);--dot-ink:rgba(42,31,23,.13);
  --night:#2A1A55;--night-shadow:rgba(42,26,85,.42);
  --on-dark:#FFFFFF;--on-dark-muted:rgba(255,255,255,.72);--on-dark-a12:rgba(255,255,255,.12);--on-dark-a20:rgba(255,255,255,.20);--hi:rgba(255,255,255,.95);
  --success:#2F8F5B;--warn:#C27A12;--error:#C2392F;
  --flag-red:#C8283E;--flag-blue:#24367A;--flag-white:#FFFFFF;--mask:#000000;--clear:transparent;
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Microsoft YaHei",system-ui,sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Apple SD Gothic Neo","Microsoft YaHei",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --r-xs:6px;--r:8px;--r-lg:10px;--r-flag:4px;--r-tag:5px;--r-icon:7px;--r-round:50%;
  --gutter:24px;--content:1168px;--nav-height:64px;--toc-offset:80px;--anchor-offset:152px;
  --shadow-window:0 48px 110px -36px var(--accent-a18),0 18px 44px -20px var(--accent-a12),0 2px 6px var(--ink-a04);
  --shadow-float:0 26px 60px -22px var(--accent-a18),0 8px 20px -10px var(--accent-a12);
  --shadow-card:0 20px 52px -24px var(--accent-a12),inset 0 1px 0 var(--hi);
  --ease-time:.2s;--reveal-time:.35s;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:var(--toc-offset)}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--font-body);font-size:17px;line-height:1.7;-webkit-font-smoothing:antialiased}
html.nav-open{overflow:hidden}
[hidden]{display:none!important}
a{color:inherit;text-underline-offset:3px}
button,input,select,textarea{font:inherit}
button{cursor:pointer}
button,summary,a{-webkit-tap-highlight-color:var(--accent-a10)}
button{color:inherit}
img,video{max-width:100%;height:auto}
svg{flex-shrink:0}
button svg,a svg{flex-shrink:0}
h1,h2,h3{font-family:var(--font-display);font-weight:700;text-wrap:balance;overflow-wrap:break-word}
h1{font-size:clamp(52px,5vw,66px);line-height:1.1;letter-spacing:-.02em}
h2{font-size:clamp(28px,3.2vw,42px);line-height:1.2;letter-spacing:-.02em;margin:0 0 24px}
h3{font-size:23px;line-height:1.35;margin:0 0 16px}
p{margin:0 0 20px}
ul,ol{padding-left:1.4em}
code{font-family:var(--font-mono);font-size:.88em;overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:20px;background:var(--panel-2);border:1px solid var(--line);border-radius:var(--r)}
pre code{overflow-wrap:normal;white-space:pre}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:var(--r-xs)}
::selection{background:var(--accent-a18);color:var(--ink)}
.wrap{width:100%;max-width:var(--content);margin-inline:auto;padding-inline:var(--gutter)}
.section{padding-top:80px;padding-bottom:80px}
.section--compact{padding-top:40px;padding-bottom:40px}
.reading-wrap{max-width:820px;margin-inline:auto;padding-inline:var(--gutter)}
.prose{min-width:0;overflow-wrap:break-word}
.prose h2{margin-top:48px}
.prose h3{margin-top:32px}
.prose li+li{margin-top:8px}
.muted{color:var(--ink-muted)}
.mono{font-family:var(--font-mono)}
.kw{color:var(--accent);font-style:normal}
.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}
.sprite{position:absolute;width:0;height:0;overflow:hidden}
.card,.panel{min-width:0;padding:28px;border:1px solid var(--line);border-radius:var(--r-lg);background:var(--panel);box-shadow:var(--shadow-card)}
.panel--inset{background:var(--panel-2);box-shadow:inset 0 1px 3px var(--ink-a08)}
.grid{display:grid;gap:24px;grid-template-columns:repeat(3,minmax(0,1fr))}
.grid>*{min-width:0}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:46px;padding:0 20px;border:1px solid var(--clear);border-radius:var(--r);font-family:var(--font-body);font-size:16px;font-weight:600;line-height:1.2;text-align:center;text-decoration:none;transition:background var(--ease-time),border-color var(--ease-time),color var(--ease-time)}
.btn svg{width:16px;height:16px}
.btn--primary,.btn-primary{background:var(--accent);color:var(--on-dark);box-shadow:0 10px 24px -10px var(--accent-a35),inset 0 1px 0 var(--on-dark-a20)}
.btn--primary:hover,.btn-primary:hover{background:var(--accent-dark)}
.btn--ghost{border-color:var(--ink);color:var(--ink);background:var(--clear)}
.btn--ghost:hover{background:var(--ink-a04)}
.btn:active{background:var(--accent-dark);color:var(--on-dark)}
.btn:disabled,.btn[aria-disabled="true"]{background:var(--panel-2);color:var(--ink-muted);border-color:var(--line);box-shadow:none;cursor:not-allowed}
.btn--small{min-height:38px;font-size:14px;padding-inline:16px}
.cta-row{display:flex;justify-content:center;gap:12px;flex-wrap:wrap}
.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:static;display:block;min-width:0;max-width:100%;overflow:hidden;margin:24px 0}
#server-status+*{margin-top:32px}
.decorated,.stripe-halo{position:relative;overflow-x:clip;max-width:100%}
.f-red{fill:var(--flag-red)}.f-blue{fill:var(--flag-blue)}.f-white{fill:var(--flag-white)}
.s-white{stroke:var(--flag-white);fill:none}.s-red{stroke:var(--flag-red);fill:none}
.st-accent{stop-color:var(--accent)}.st-berry{stop-color:var(--berry)}.st-light{stop-color:var(--accent-light)}
.st-fade{stop-color:var(--accent);stop-opacity:0}.st-soft{stop-color:var(--accent);stop-opacity:.12}.st-band-a{stop-color:var(--accent-light);stop-opacity:.45}
.c-on-dark{color:var(--on-dark)}
.ann-toggle{position:absolute;opacity:0;pointer-events:none}
.ann{position:relative;display:flex;align-items:center;justify-content:center;gap:12px;min-height:40px;padding:8px 56px;background:var(--accent);color:var(--on-dark);font-size:14px;line-height:1.3}
.ann-toggle:checked+.ann{display:none}
.ann__new{display:inline-flex;align-items:center;height:22px;padding:0 8px;border-radius:var(--r-xs);background:var(--berry);color:var(--on-dark);font-size:12px;font-weight:700;letter-spacing:.04em;flex-shrink:0}
.ann__text{font-weight:500}
.ann__link{color:var(--on-dark);font-weight:600;text-decoration:underline;text-underline-offset:3px;min-height:24px;display:inline-flex;align-items:center;flex-shrink:0}
.ann__x{position:absolute;right:16px;top:50%;display:grid;place-items:center;width:28px;height:28px;margin-top:-14px;border:0;border-radius:var(--r-xs);background:var(--clear);color:var(--on-dark-muted);cursor:pointer}
.ann__x:hover{color:var(--on-dark);background:var(--on-dark-a12)}
.ann__x svg{width:14px;height:14px}
#site-header{position:relative;z-index:50}
.nav{position:relative;z-index:53;display:flex;align-items:center;flex-wrap:nowrap;gap:24px;max-width:var(--content);height:var(--nav-height);margin:0 auto;padding-inline:var(--gutter)}
.brand{display:inline-flex;align-items:center;gap:10px;text-decoration:none;color:var(--ink);flex-shrink:0}
.brand img{width:28px;height:28px;flex-shrink:0}
.brand__name{font-family:var(--font-display);font-size:19px;font-weight:700;letter-spacing:-.02em;white-space:nowrap}
.brand__zh{font-weight:500;color:var(--ink-muted)}
.nav__desktop{flex:1;min-width:0}
.nav__list{display:flex;align-items:center;justify-content:center;list-style:none;margin:0;padding:0;font-size:14.5px;line-height:1;white-space:nowrap}
.nav__list li{display:flex;align-items:center}
.nav__list li+li::before{content:"·";margin:0 11px;color:var(--line-strong);font-weight:700}
.nav__list a{position:relative;display:inline-flex;align-items:center;min-height:28px;padding:6px 0;color:var(--ink-muted);text-decoration:none;transition:color var(--ease-time)}
.nav__list a:hover{color:var(--ink)}
.nav__list a[aria-current="page"]{color:var(--ink);font-weight:600}
.nav__list a[aria-current="page"]::after{content:"";position:absolute;left:50%;bottom:-4px;width:4px;height:4px;margin-left:-2px;border-radius:var(--r-round);background:var(--accent)}
.nav__end{display:flex;align-items:center;gap:14px;flex-shrink:0}
.lang-box{position:relative}
.lang{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:44px;width:auto;height:34px;padding:0 10px;border:0;border-radius:var(--r);background:var(--clear);color:var(--ink-muted);font:inherit;font-size:14px;cursor:pointer;white-space:nowrap}
.lang:hover{color:var(--ink);background:var(--ink-a04)}
.lang svg{width:15px;height:15px}
.lang span{white-space:nowrap}
.lang-panel{position:absolute;right:0;top:calc(100% + 10px);z-index:60;width:184px;padding:6px;border:1px solid var(--line);border-radius:var(--r);background:var(--panel);box-shadow:var(--shadow-float)}
.lang-panel a{display:flex;align-items:center;min-height:44px;padding:8px 12px;border-radius:var(--r-xs);text-decoration:none;font-size:14px}
.lang-panel a:hover,.lang-panel a[aria-current="true"]{background:var(--accent-a10);color:var(--accent)}
.login{display:inline-flex;align-items:center;justify-content:center;height:36px;padding:0 16px;border-radius:var(--r);background:var(--ink);color:var(--panel);font-size:14px;font-weight:600;text-decoration:none;white-space:nowrap;box-shadow:inset 0 1px 0 var(--on-dark-a12);transition:background var(--ease-time)}
.login:hover{background:var(--accent-dark)}
.nav-toggle{display:none;align-items:center;justify-content:center;flex-direction:column;gap:4px;min-width:44px;min-height:44px;padding:10px;border:1px solid var(--line);border-radius:var(--r);background:var(--panel);color:var(--ink)}
.nav-toggle__line{display:block;width:20px;height:2px;background:currentColor;flex-shrink:0}
.nav-drawer{position:fixed;z-index:52;inset-inline:0;top:var(--drawer-top,var(--nav-height));height:calc(100dvh - var(--drawer-top,var(--nav-height)));max-height:calc(100dvh - var(--drawer-top,var(--nav-height)));overflow-y:auto;overscroll-behavior:contain;padding:16px var(--gutter) 32px;background:var(--panel);border-top:1px solid var(--line)}
.nav-drawer a{display:flex;align-items:center;width:100%;min-height:44px;padding:10px 12px;text-decoration:none;border-bottom:1px solid var(--line);color:var(--ink)}
.nav-drawer a[aria-current]{color:var(--accent);font-weight:600}
.nav-drawer__languages{margin-top:24px;border-top:1px solid var(--line)}
.nav-veil{position:fixed;z-index:51;inset:var(--drawer-top,var(--nav-height)) 0 0;border:0;padding:0;background:var(--ink-a14)}
.site-footer{padding-top:56px;padding-bottom:24px;border-top:1px solid var(--line);background:var(--panel-2)}
.footer-grid{display:grid;grid-template-columns:1.3fr 1fr 1fr;gap:48px}
.footer-grid>*{min-width:0}
.footer-about p{max-width:340px;margin-top:16px;color:var(--ink-muted);font-size:15px}
.footer-title{font-size:15px;font-weight:700;margin-bottom:12px}
.footer-links{display:flex;flex-wrap:wrap;gap:8px 18px;margin:0;padding:0;list-style:none}
.footer-links a{display:inline-flex;align-items:center;min-height:28px;font-size:14px;color:var(--ink-muted);text-decoration:none}
.footer-links a:hover{color:var(--accent)}
.footer-languages{margin-top:32px;padding-top:20px;border-top:1px solid var(--line)}
.footer-bottom{display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:12px;margin-top:20px;font-size:13px;color:var(--ink-muted)}
.footer-legal{display:flex;flex-wrap:wrap;gap:16px}
.footer-legal a{display:inline-flex;align-items:center;min-height:24px}
@media(max-width:1180px){
  .nav{gap:16px}
  .nav__list{font-size:13.5px}
  .nav__list li+li::before{margin:0 7px}
  .nav__end{gap:8px}
}
@media(max-width:1080px){
  .nav__desktop{display:none}
  .nav__end{margin-left:auto}
  .nav-toggle{display:flex}
}
@media(min-width:1081px){.nav-drawer,.nav-veil{display:none!important}}
@media(max-width:768px){
  h1{font-size:clamp(28px,7vw,40px)}
  .grid{grid-template-columns:1fr}
  .section{padding-top:56px;padding-bottom:56px}
  .footer-grid{grid-template-columns:1fr;gap:28px}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .no-break{white-space:normal}
  .tilt,[data-tilt]{transform:none!important}
  .decorated,.stripe-halo{max-width:100%}
  .nav{gap:8px}
  .nav__end{gap:4px;margin-left:auto}
  .brand{gap:6px}
  .brand__name{font-size:17px}
  .brand img{width:25px;height:25px}
  .login{padding-inline:12px;font-size:13px}
  .lang{padding-inline:8px}
  .lang span{display:none}
  .ann{font-size:12.5px;padding-inline:44px;gap:8px;flex-wrap:wrap}
  .card,.panel{padding:20px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation:none!important;transition:none!important}
  .reveal,.reveal.pending{opacity:1;transform:none}
}