:root {
  --bg:#F8F2E4;
  --bg-panel:#FFFCF5;
  --bg-panel-2:#EFE7D4;
  --border:#E2D8C2;
  --accent:#A9B01E;
  --accent-2:#C9C24A;
  --accent-dark:#5E6210;
  --text:#2A2317;
  --text-muted:#6E6452;
  --success:#3F8A4E;
  --warn:#C98A1A;
  --error:#B8412F;
  --hero-top:#FBF7EC;
  --hero-bottom:#F2E9D5;
  --dusk-sand:#F1E4C4;
  --dusk-gold:#DCC993;
  --horizon:#FFF7E4;
  --tower-shade:#EBE0C5;
  --rock:#45421A;
  --on-dark:#F4ECDA;
  --highlight:#FFFFFF;
  --flag-red:#C8352E;
  --flag-blue:#223A70;
  --flag-white:#FFFFFF;
  --font-display:"Inter","Noto Sans SC","PingFang SC","Hiragino Sans GB","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-xl:28px;
  --r-lg:18px;
  --r-md:14px;
  --r-sm:10px;
  --r-pill:999px;
  --gutter:48px;
  --header-height:72px;
  --toc-height:66px;
  --shadow-soft:0 24px 56px -22px color-mix(in srgb,var(--accent) 10%,transparent),0 10px 24px -14px color-mix(in srgb,var(--accent-dark) 14%,transparent),inset 0 1px 0 var(--highlight);
  --shadow-card:0 26px 52px -20px color-mix(in srgb,var(--accent-dark) 30%,transparent),0 4px 12px -6px color-mix(in srgb,var(--text) 12%,transparent),inset 0 1px 0 var(--highlight);
  --shadow-harbor:0 48px 96px -36px color-mix(in srgb,var(--accent) 12%,transparent),0 30px 60px -34px color-mix(in srgb,var(--accent-dark) 34%,transparent);
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;scroll-padding-top:calc(var(--header-height) + 16px);-webkit-text-size-adjust:100%}
html.nav-open{overflow:hidden}
body{margin:0;min-width:320px;font-family:var(--font-body);font-size:16px;line-height:1.6;color:var(--text);background:var(--bg);-webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility}
a{color:inherit}
button,input{font:inherit}
button{cursor:pointer}
img,svg{max-width:100%}
img{height:auto}
svg{vertical-align:middle}
:focus-visible{outline:2px solid var(--accent-dark);outline-offset:3px;border-radius:6px}
.visually-hidden{position:absolute;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.no-break{white-space:nowrap}
.wrap{width:100%;max-width:1320px;margin-inline:auto;padding-inline:var(--gutter)}
.wrap > *, .hero__grid > *, .panel > *, .card > *{min-width:0}
.sec{padding-top:88px;padding-bottom:88px}
.sec-heading{margin:0 0 16px;font:800 clamp(32px,4vw,48px)/1.2 var(--font-display);letter-spacing:-.02em;text-wrap:balance}
.sec-heading em,h1 em,h2 em{font-style:normal;color:var(--accent-dark)}
h1{font:800 clamp(52px,5vw,72px)/1.12 var(--font-display);letter-spacing:-.02em;text-wrap:balance}
h2,h3{font-family:var(--font-display);letter-spacing:-.02em}
p{margin-block:0 1.25em}
code,pre{font-family:var(--font-mono)}
code{overflow-wrap:anywhere}
pre{max-width:100%;overflow-x:auto;padding:20px;border-radius:var(--r-md);background:var(--bg-panel-2)}
pre code{overflow-wrap:normal}
.prose{max-width:78ch;min-width:0}
.prose h2{margin-top:2.4em}
.prose h3{margin-top:1.7em}
.prose img{max-width:100%}
.prose a{text-decoration-color:var(--accent-dark);text-underline-offset:3px}
.prose ol{counter-reset:step;list-style:none;padding-left:0}
.prose ol > li{counter-increment:step;position:relative;padding-left:3rem;margin-bottom:1.1rem}
.prose ol > li::before{content:counter(step);position:absolute;left:0;top:0;width:2rem;height:2rem;display:grid;place-items:center;border-radius:50%;background:var(--accent-dark);color:var(--bg-panel);font:700 .85rem var(--font-mono)}
.panel{padding:32px;border-radius:var(--r-xl);background:var(--bg-panel-2);min-width:0}
.card{padding:24px;border:1px solid var(--border);border-radius:var(--r-md);background:var(--bg-panel);box-shadow:var(--shadow-soft);min-width:0}
.badge{display:inline-flex;align-items:center;gap:8px;max-width:100%;overflow:hidden;padding:5px 12px;border-radius:var(--r-pill);background:var(--bg-panel-2);color:var(--accent-dark);font-size:13px;font-weight:700}
.badge__dot{width:8px;height:8px;flex-shrink:0;border-radius:50%;background:var(--accent)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:10px 20px;border-radius:var(--r-md);border:1px solid transparent;text-decoration:none;font-weight:700;line-height:1.25;white-space:nowrap;flex-shrink:0;transition:transform .2s,background-color .2s,box-shadow .2s}
.btn:hover{transform:translateY(-2px)}
.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}
.btn-primary{background:linear-gradient(135deg,var(--accent-2),var(--accent) 62%);color:var(--text);box-shadow:inset 0 1px 0 color-mix(in srgb,var(--highlight) 55%,transparent),0 10px 20px -10px color-mix(in srgb,var(--accent-dark) 55%,transparent)}
.btn-primary:hover{box-shadow:var(--shadow-soft)}
.btn-secondary{border-color:var(--text);background:transparent;color:var(--text)}
.btn-secondary:hover{background:var(--bg-panel)}
.btn-quiet{background:var(--bg-panel-2);color:var(--text)}
.btn-small{font-size:14px;min-height:40px;padding-inline:16px}
.reveal{transition:opacity .55s ease,transform .55s ease}
.reveal.pending{opacity:0;transform:translateY(16px)}
.reveal.shown{opacity:1;transform:none}
/* The single site-wide paper grain is applied here, not repeated per section. */
body::before{content:"";position:fixed;inset:0;z-index:70;pointer-events:none;opacity:.03;mix-blend-mode:multiply;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='128' height='128'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.7' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='128' height='128' filter='url(%23n)' opacity='.6'/%3E%3C/svg%3E")}
.notice{background:var(--text);color:var(--on-dark);font-size:13.5px}
.notice .wrap{display:flex;align-items:center;justify-content:center;gap:28px;min-height:40px}
.notice__text{margin:0;display:flex;align-items:center;gap:16px;flex-wrap:wrap;justify-content:center}
.notice__tag{color:var(--accent);font-weight:700}
.notice__sub{color:color-mix(in srgb,var(--on-dark) 78%,transparent)}
.notice__link{font-weight:600;text-decoration:underline;text-underline-offset:5px;white-space:nowrap}
.notice__link:hover{color:var(--accent)}
.site-header{position:relative;z-index:30;background:var(--hero-top);border-bottom:1px solid var(--border)}
.site-header .wrap{display:flex;align-items:center;gap:24px;min-height:var(--header-height)}
.brand{display:flex;align-items:center;gap:10px;text-decoration:none;flex:none}
.brand__mark{display:block;width:36px;height:36px;flex:none}
.brand__en{font:800 20px var(--font-display);letter-spacing:-.01em}
.brand__zh{font-size:14px;font-weight:500;color:var(--text-muted)}
.nav{flex:1;display:flex;justify-content:center;min-width:0}
.nav__list{display:flex;align-items:center;gap:4px;list-style:none;margin:0;padding:0}
.nav__link{display:flex;align-items:center;gap:6px;padding:8px 12px;border-radius:var(--r-pill);font-size:14.5px;font-weight:500;color:var(--text-muted);text-decoration:none;white-space:nowrap;transition:background-color .2s,color .2s}
.nav__link svg,.btn-login svg,.lang-switch svg,.menu-btn svg{width:16px;height:16px;flex:none;fill:none;stroke:currentColor;stroke-width:1.7;stroke-linecap:round;stroke-linejoin:round}
.nav__link:hover,.nav__link[aria-current="page"]{background:var(--bg-panel-2);color:var(--accent-dark)}
.nav__link[aria-current="page"]{font-weight:700}
.header-actions{display:flex;align-items:center;gap:10px;flex:none}
.lang-control{position:relative}
.lang-switch{display:flex;align-items:center;gap:6px;min-height:40px;width:auto;padding:0 12px;border:1px solid var(--border);border-radius:var(--r-pill);background:var(--bg-panel);color:var(--text);font-size:14px;white-space:nowrap}
.lang-switch__caret{font-size:11px;color:var(--text-muted)}
.lang-menu{position:absolute;right:0;top:calc(100% + 8px);z-index:35;width:max-content;min-width:160px;padding:6px;border:1px solid var(--border);border-radius:var(--r-md);background:var(--bg-panel);box-shadow:var(--shadow-card)}
.lang-menu[hidden],.mobile-nav[hidden]{display:none!important}
.lang-menu a{display:flex;align-items:center;min-height:40px;padding:7px 12px;border-radius:var(--r-sm);text-decoration:none}
.lang-menu a:hover,.lang-menu a[aria-current="true"]{background:var(--bg-panel-2);color:var(--accent-dark)}
.btn-login{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-height:40px;padding:0 18px;border-radius:var(--r-pill);background:var(--text);color:var(--bg-panel);font-size:14.5px;font-weight:700;text-decoration:none;white-space:nowrap;box-shadow:0 8px 18px -10px color-mix(in srgb,var(--text) 60%,transparent)}
.btn-login:hover{background:color-mix(in srgb,var(--text) 86%,var(--accent-dark))}
.menu-btn{display:none;align-items:center;justify-content:center;min-width:44px;min-height:44px;border:1px solid var(--border);border-radius:var(--r-sm);background:var(--bg-panel);color:var(--text)}
.mobile-nav{display:none}
.site-footer{padding-top:64px;background:var(--text);color:var(--on-dark)}
.site-footer__grid{display:grid;grid-template-columns:1.5fr 1fr 1.3fr 1fr;gap:48px;padding-bottom:56px}
.site-footer .brand{color:var(--on-dark)}
.site-footer .brand__zh{color:var(--on-dark)}
.site-footer__intro{max-width:28ch;margin-top:16px;color:var(--on-dark)}
.site-footer h2{margin:0 0 18px;font-size:15px}
.site-footer ul{list-style:none;padding:0;margin:0;display:grid;gap:9px}
.site-footer a{display:inline-flex;align-items:center;min-height:28px;text-decoration:none}
.site-footer a:hover{text-decoration:underline;text-underline-offset:4px;color:var(--accent)}
.site-footer__bottom{display:flex;justify-content:space-between;gap:24px;flex-wrap:wrap;padding-top:20px;padding-bottom:24px;border-top:1px solid color-mix(in srgb,var(--on-dark) 24%,transparent);font-size:13px}
.site-footer__bottom a{margin-left:16px}
#server-status{position:relative;display:block;max-width:100%;overflow:hidden;margin-bottom:24px}
body:has(.toc-tabs) section[id]{scroll-margin-top:calc(var(--header-height) + var(--toc-height) + 20px)}
@media(max-width:1150px){
  :root{--gutter:32px}
  .nav__link{padding-inline:8px;font-size:13px}
  .site-header .wrap{gap:12px}
}
@media(max-width:980px){
  .nav{display:none}
  .header-actions{margin-left:auto}
  .menu-btn{display:flex}
  .mobile-nav{display:block;position:absolute;top:100%;left:0;right:0;z-index:31;max-height:calc(100dvh - var(--header-height));overflow-y:auto;overscroll-behavior:contain;padding:12px var(--gutter) 20px;background:var(--bg-panel);border-bottom:1px solid var(--border);box-shadow:var(--shadow-card)}
  .mobile-nav a{display:flex;align-items:center;width:100%;min-height:48px;padding:12px 16px;gap:10px;border-radius:var(--r-sm);text-decoration:none}
  .mobile-nav a:hover,.mobile-nav a[aria-current="page"]{background:var(--bg-panel-2);color:var(--accent-dark)}
  .mobile-nav__languages{border-top:1px solid var(--border);margin-top:10px;padding-top:10px}
  .site-footer__grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:768px){
  :root{--gutter:24px}
  h1{font-size:clamp(28px,7vw,40px)}
  .sec{padding-top:64px;padding-bottom:64px}
}
@media(max-width:640px){
  :root{--gutter:16px}
  .notice .wrap{flex-wrap:wrap;gap:4px 12px;padding-block:8px}
  .notice__text{flex:1 1 100%;min-width:0;gap:0 12px}
  .notice__tag,.notice__sub{overflow-wrap:anywhere}
  .notice__link{white-space:normal;text-align:right;margin-left:auto}
  .no-break{white-space:normal}
  .site-header .wrap{gap:8px}
  .brand__en{font-size:18px}
  .brand__mark{width:32px;height:32px}
  .lang-switch{padding-inline:9px}
  .btn-login{padding-inline:12px}
  .site-footer__grid{grid-template-columns:1fr;gap:28px}
  .site-footer__bottom a{margin:0 16px 0 0}
  .panel{padding:20px}
  .sec-heading{font-size:32px}
  .tilt-card,.tilt-hover,[data-tilt]{transform:none!important}
}
@media(max-width:400px){
  .lang-switch svg,.btn-login svg{display:none}
  .header-actions{gap:6px}
}
@media(prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  .reveal,.reveal.pending{opacity:1;transform:none;transition:none}
  .btn{transition:none}
}