:root {
  --bg:#F4F3EE;--bg-top:#FAF9F5;--bg-bottom:#EFEDE5;
  --panel:#FFFFFF;--panel-2:#EAE8E0;--chrome-top:#F6F4EF;--chrome-bottom:#EEECE5;--row:#FAF9F6;
  --border:#DEDBD0;--border-strong:#C9C5B8;
  --accent:#FFB81F;--accent-light:#FFC94D;--accent-dark:#C98605;
  --text:#0E2A3B;--text-2:#1A4058;--text-muted:#5D6B72;
  --success:#2F9E62;--warn:#D9822B;--error:#D2483A;
  --coral:#E3764F;--apricot:#E9D9C4;--apricot-soft:#F7F0E6;--apricot-edge:#E0CDB3;
  --accent-rgb:255 184 31;--accent-dark-rgb:201 134 5;--text-rgb:14 42 59;
  --white-rgb:255 255 255;--bg-top-rgb:250 249 245;--success-rgb:47 158 98;
  --ic-navy:#2C4E68;--ic-navy-bg:#E5EBF0;--ic-moss:#5B8A4B;--ic-moss-bg:#E7EFE1;
  --ic-coral:#C7613E;--ic-coral-bg:#F9E6DD;--ic-teal:#2D8786;--ic-teal-bg:#DDEFEC;
  --ic-marigold:#B97C08;--ic-marigold-bg:#FFF0CC;--ic-apricot:#94693F;--ic-apricot-bg:#F3E7D7;
  --flag-red:#CF323B;--flag-blue:#22468E;--flag-green:#1E8A4C;--flag-white:#FFFFFF;
  --r-xs:8px;--r-sm:10px;--r-md:14px;--r-lg:20px;--r-xl:24px;--r-2xl:32px;--r-pill:999px;
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Apple SD Gothic Neo","Microsoft YaHei","Malgun Gothic",system-ui,sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans","Apple SD Gothic Neo","Microsoft YaHei","Malgun Gothic",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,Consolas,monospace;
  --shadow-board:0 40px 80px -30px rgb(var(--text-rgb) / .12),0 18px 36px -18px rgb(var(--text-rgb) / .12);
  --shadow-window:0 34px 70px -18px rgb(var(--accent-rgb) / .10),0 24px 48px -26px rgb(var(--text-rgb) / .30);
  --shadow-float:0 22px 48px -16px rgb(var(--accent-rgb) / .14),0 12px 26px -14px rgb(var(--text-rgb) / .22);
  --shadow-soft:0 1px 2px rgb(var(--text-rgb) / .06);
  --gutter:40px;--header-height:72px;--toc-offset:154px;
}
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:calc(var(--header-height) + 16px)}
html.nav-open{overflow:hidden}
body{margin:0;background:var(--bg);color:var(--text);font-family:var(--font-body);font-size:16px;line-height:1.6;-webkit-font-smoothing:antialiased}
button,input,select{font:inherit}
button{cursor:pointer}
a{color:inherit}
a,button,summary,[role="tab"]{touch-action:manipulation}
a:focus-visible,button:focus-visible,summary:focus-visible,[role="tab"]:focus-visible{outline:2px solid var(--accent-dark);outline-offset:3px}
img,svg{max-width:100%}
svg{flex-shrink:0}
code{overflow-wrap:anywhere;font-family:var(--font-mono)}
pre{max-width:100%;overflow-x:auto;padding:20px;border-radius:var(--r-md);background:var(--panel)}
pre code{overflow-wrap:normal}
table{border-collapse:collapse}
th,td{word-break:keep-all}
th{white-space:nowrap}
h1,h2,h3{font-family:var(--font-display);color:var(--text);line-height:1.2;text-wrap:balance}
h1{font-size:clamp(52px,5vw,68px);line-height:1.1;letter-spacing:-.03em}
h2{font-size:clamp(28px,3vw,42px);letter-spacing:-.02em}
h3{font-size:clamp(21px,2vw,27px)}
p{margin-block:0 1em}
.no-break{white-space:nowrap}
.wrap{width:100%;max-width:1360px;margin-inline:auto;padding-inline:var(--gutter)}
.sec{padding-top:84px;padding-bottom:84px}
.panel{min-width:0;background:var(--panel);border-radius:var(--r-xl);box-shadow:var(--shadow-window),inset 0 1px rgb(var(--white-rgb) / .8)}
.reveal{transition:opacity .6s ease,transform .6s ease}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
[data-count]{font-variant-numeric:tabular-nums;display:inline-block;min-width:4ch}
#server-status{position:relative;display:block;max-width:100%;overflow:hidden;margin-block:24px 32px}
#server-status + *{margin-top:24px}
body:has(.toc-tabs) section[id]{scroll-margin-top:var(--toc-offset)}
/* Shared masthead */
.topbar{position:relative;z-index:30;background:rgb(var(--bg-top-rgb) / .94);border-bottom:1px solid rgb(var(--text-rgb) / .06)}
.topbar-in{height:var(--header-height);display:flex;align-items:center;gap:36px}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;color:var(--text);flex:none}
.brand-mark{width:34px;height:34px;flex:none}
.brand-en{font-family:var(--font-display);font-weight:800;font-size:21px;letter-spacing:-.02em;line-height:1}
.brand-zh{font-size:14px;font-weight:500;color:var(--text-muted);padding-left:10px;border-left:1px solid var(--border);line-height:1.1}
.nav-list{list-style:none;margin:0;padding:0;display:flex;align-items:center;gap:2px}
.nav-list>li{position:relative}
.nav-link{position:relative;display:inline-flex;align-items:center;gap:5px;height:40px;padding:0 14px;border:0;border-radius:var(--r-pill);background:transparent;color:var(--text);font-size:15px;font-weight:500;text-decoration:none;cursor:pointer;white-space:nowrap}
.nav-link:hover,.lang:hover{background:rgb(var(--text-rgb) / .05)}
.nav-link[aria-current="page"]{font-weight:700}
.nav-link[aria-current="page"]::after{content:"";position:absolute;left:14px;right:14px;bottom:5px;height:2px;border-radius:var(--r-pill);background:var(--text)}
.nav-caret{width:10px;height:10px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round}
.nav-drop{position:absolute;top:calc(100% + 10px);left:-8px;min-width:280px;padding:10px;background:var(--panel);border-radius:var(--r-lg);box-shadow:0 0 0 1px rgb(var(--text-rgb) / .06),var(--shadow-float);opacity:0;visibility:hidden;transform:translateY(-6px);transition:opacity .18s ease,transform .18s ease,visibility .18s}
.nav-more:hover .nav-drop,.nav-more:focus-within .nav-drop,.nav-more.is-open .nav-drop{opacity:1;visibility:visible;transform:none}
.drop-group+.drop-group{margin-top:6px;padding-top:6px;border-top:1px solid var(--border)}
.drop-title{display:block;padding:6px 12px 4px;font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;color:var(--text-muted)}
.drop-link{display:flex;flex-direction:column;padding:8px 12px;border-radius:var(--r-md);text-decoration:none}
.drop-link:hover{background:var(--row)}
.drop-link b{font-size:14.5px;line-height:1.3}
.drop-link span{font-size:12.5px;color:var(--text-muted)}
.topbar-actions{margin-left:auto;display:flex;align-items:center;gap:10px;flex:none}
.lang-box{position:relative}
.lang{display:inline-flex;align-items:center;gap:6px;min-height:40px;width:auto;padding:0 12px;border:0;border-radius:var(--r-pill);background:transparent;color:var(--text-muted);font-size:14px;font-weight:500;white-space:nowrap}
.lang svg{width:16px;height:16px;fill:none;stroke:currentColor;stroke-width:1.6}
.lang-list{position:absolute;right:0;top:calc(100% + 8px);z-index:35;min-width:170px;padding:8px;border-radius:var(--r-md);background:var(--panel);box-shadow:var(--shadow-float)}
.lang-list[hidden]{display:none}
.lang-list a{display:flex;align-items:center;min-height:40px;padding-inline:12px;border-radius:var(--r-sm);text-decoration:none}
.lang-list a:hover{background:var(--row)}
.login{display:inline-flex;align-items:center;justify-content:center;min-height:42px;padding:0 22px;border-radius:var(--r-pill);background:var(--text);color:var(--panel);font-size:15px;font-weight:700;text-decoration:none;white-space:nowrap;box-shadow:0 10px 22px -12px rgb(var(--text-rgb) / .6);transition:transform .18s ease}
.login:hover{transform:translateY(-1px)}
.menu-toggle{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;border:0;border-radius:var(--r-sm);background:transparent;color:var(--text)}
.menu-toggle svg{width:23px;height:23px;fill:none;stroke:currentColor;stroke-width:2;stroke-linecap:round}
.mobile-nav{display:none}
.nav-veil{display:none}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:10px;min-height:56px;padding:0 30px;border:0;border-radius:var(--r-pill);font-size:17px;font-weight:700;text-decoration:none;white-space:nowrap;flex-shrink:0;transition:transform .18s ease}
.btn:hover{transform:translateY(-2px)}
.btn svg{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:2.2;stroke-linecap:round}
.btn-primary{color:var(--text);background:linear-gradient(180deg,var(--accent-light),var(--accent));box-shadow:0 16px 32px -14px rgb(var(--accent-rgb) / .9),inset 0 1px rgb(var(--white-rgb) / .55),inset 0 -2px rgb(var(--accent-dark-rgb) / .35)}
.btn-ghost,.btn-secondary{color:var(--text);background:rgb(var(--white-rgb) / .4);box-shadow:inset 0 0 0 1.5px var(--text)}
.btn:disabled{opacity:.55;cursor:not-allowed;transform:none}
.btn-small{min-height:42px;padding-inline:20px;font-size:14px}
.site-footer{background:var(--text);color:var(--panel);padding-top:64px}
.footer-grid{display:grid;grid-template-columns:1.5fr 1fr 1.2fr 1fr;gap:38px}
.footer-brand{max-width:29em}
.footer-brand .brand{color:var(--panel)}
.footer-brand p{margin-top:18px;color:var(--apricot)}
.footer-heading{font-size:14px;font-weight:700;margin:0 0 16px}
.footer-links{list-style:none;padding:0;margin:0;display:grid;gap:7px}
.footer-links a{display:inline-flex;align-items:center;min-height:30px;color:var(--apricot);text-decoration:none}
.footer-links a:hover{text-decoration:underline;color:var(--panel)}
.footer-bottom{margin-top:54px;padding-top:20px;padding-bottom:22px;border-top:1px solid rgb(var(--white-rgb) / .2);display:flex;justify-content:space-between;flex-wrap:wrap;gap:12px;color:var(--apricot);font-size:13px}
.footer-bottom a{margin-left:18px}
@media(max-width:1080px){.topbar-in{gap:16px}.nav-link{padding-inline:9px}.footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:900px){
  .desktop-nav{display:none}
  .topbar-actions{margin-left:auto;gap:4px}
  .menu-toggle{display:inline-flex}
  .mobile-nav{display:none;position:absolute;z-index:32;top:100%;left:0;right:0;max-height:calc(100dvh - var(--header-height));overflow-y:auto;overscroll-behavior:contain;padding:12px var(--gutter) 22px;background:var(--panel);box-shadow:var(--shadow-float)}
  .mobile-nav.is-open{display:block}
  .mobile-nav a{display:flex;width:100%;align-items:center;min-height:48px;padding:10px 14px;border-radius:var(--r-sm);text-decoration:none}
  .mobile-nav a:hover,.mobile-nav a[aria-current="page"]{background:var(--row);font-weight:700}
  .mobile-nav strong{display:block;padding:14px 14px 2px;font-size:12px;color:var(--text-muted)}
  .nav-veil.is-open{display:block;position:fixed;z-index:20;inset:var(--header-height) 0 0;background:rgb(var(--text-rgb) / .32)}
}
@media(max-width:768px){:root{--header-height:64px;--gutter:20px}h1{font-size:clamp(28px,9vw,40px);letter-spacing:-.02em}.sec{padding-top:56px;padding-bottom:56px}.btn{min-height:52px;padding-inline:22px;font-size:16px}.footer-grid{gap:28px}}
@media(max-width:640px){:root{--gutter:18px}.no-break{white-space:normal}.brand-zh{display:none}.lang-box{display:none}.footer-grid{grid-template-columns:minmax(0,1fr)}.wrap{padding-inline:var(--gutter)}.tilt,[class*="tilt"]{transform:none!important}.decor-halo,.stripe-halo{max-width:100%;overflow-x:clip}}
@media(max-width:360px){:root{--gutter:16px}.brand-en{font-size:19px}.login{padding-inline:14px;font-size:14px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.reveal,.reveal.pending{opacity:1;transform:none;transition:none}.btn,.login{transition:none}}