:root{
  color-scheme: light dark;
  --ground:#f9f9f7; --surface:#fcfcfb; --ink:#0b0b0b; --muted:#52514e;
  --accent:#184f95; --border:rgba(11,11,11,.1); --code:#f2f2ef;
  --ui:ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --mono:ui-monospace,SFMono-Regular,Menlo,monospace;
}
:root[data-theme="dark"]{
  --ground:#0d0d0d; --surface:#1a1a19; --ink:#fff; --muted:#c3c2b7;
  --accent:#6da7ec; --border:rgba(255,255,255,.12); --code:#232322;
}
@media (prefers-color-scheme: dark){
  :root:not([data-theme="light"]){
    --ground:#0d0d0d; --surface:#1a1a19; --ink:#fff; --muted:#c3c2b7;
    --accent:#6da7ec; --border:rgba(255,255,255,.12); --code:#232322;
  }
}
*{box-sizing:border-box}
html{scroll-behavior:smooth; scroll-padding-top:4.5rem}
body{margin:0;background:var(--ground);color:var(--ink);font:16px/1.65 var(--ui)}

.top{position:sticky;top:0;z-index:20;display:flex;align-items:center;gap:.6rem;
  height:3.25rem;padding:0 1rem;background:color-mix(in srgb,var(--ground) 88%,transparent);
  backdrop-filter:blur(8px);border-bottom:1px solid var(--border)}
.brand{font-weight:700;color:var(--ink);text-decoration:none;letter-spacing:-.01em}
.tag{font-size:.7rem;text-transform:uppercase;letter-spacing:.08em;color:var(--muted);
  border:1px solid var(--border);border-radius:99px;padding:.1rem .45rem}
.top button{margin-left:auto;background:none;border:1px solid var(--border);border-radius:.5rem;
  color:var(--ink);font-size:1rem;line-height:1;padding:.35rem .5rem;cursor:pointer}
.top button.menu{margin-left:0;display:none}
.top .theme{margin-left:auto}

.shell{display:grid;grid-template-columns:17rem minmax(0,1fr);gap:0;align-items:start}
.side{position:sticky;top:3.25rem;max-height:calc(100vh - 3.25rem);overflow:auto;
  padding:1.25rem .75rem 3rem;border-right:1px solid var(--border);font-size:.9rem}
.nav-sec{margin:0 0 .15rem}
.nav-sec>summary{cursor:pointer;list-style:none;padding:.3rem .5rem;border-radius:.4rem}
.nav-sec>summary::-webkit-details-marker{display:none}
.nav-sec>summary::before{content:"›";display:inline-block;width:.9rem;color:var(--muted);transition:transform .15s}
.nav-sec[open]>summary::before{transform:rotate(90deg)}
.nav-sec>summary a{color:var(--ink);text-decoration:none}
.nav-sec>summary a.active{color:var(--accent);font-weight:600}
.nav-sec ul{list-style:none;margin:.1rem 0 .4rem;padding:0 0 0 1.35rem}
.nav-sec ul a{display:block;padding:.18rem .4rem;border-radius:.35rem;color:var(--muted);
  text-decoration:none;font-size:.85rem;line-height:1.35}
.nav-sec ul a:hover{background:var(--surface);color:var(--ink)}

main{min-width:0;padding:2rem clamp(1rem,4vw,3rem) 6rem;max-width:56rem}
h1{font-size:1.75rem;line-height:1.25;margin:2.5rem 0 .4rem;letter-spacing:-.015em}
.chapter:first-child h1{margin-top:0}
h2{font-size:1.2rem;margin:2rem 0 .5rem}
h3{font-size:1rem;margin:1.5rem 0 .4rem}
p,li{max-width:68ch}
a{color:var(--accent)}
.meta{display:flex;align-items:center;gap:.5rem;margin:.1rem 0 1.4rem;font-size:.78rem;color:var(--muted)}
.chip{border:1px solid var(--border);border-radius:99px;padding:.05rem .45rem}
.meta code{font-size:.78rem}
.raw{font-size:.78rem}
code{background:var(--code);border-radius:.3rem;padding:.1rem .3rem;font-family:var(--mono);font-size:.86em}
pre{background:var(--code);border:1px solid var(--border);border-radius:.6rem;padding:.9rem;overflow:auto}
pre code{background:none;padding:0}
blockquote{margin:1.2rem 0;padding:.2rem 1rem;border-left:3px solid var(--border);color:var(--muted)}
table{border-collapse:collapse;width:100%;margin:1.2rem 0;font-size:.9rem;display:block;overflow-x:auto}
th,td{border:1px solid var(--border);padding:.45rem .6rem;text-align:left;vertical-align:top}
th{background:var(--surface)}
hr{border:0;border-top:1px solid var(--border);margin:2.5rem 0}
.chapter{border-top:1px solid var(--border);padding-top:.5rem}
.chapter:first-child{border-top:0}
pre.mermaid{background:var(--surface);text-align:center}

@media (max-width:52rem){
  .shell{grid-template-columns:1fr}
  .top button.menu{display:block}
  .side{position:fixed;inset:3.25rem 0 0 0;max-height:none;background:var(--ground);
    z-index:15;display:none;border-right:0}
  body.nav-open .side{display:block}
  main{padding-bottom:4rem}
}