/* Page frame: tokens, base, header, hero, sticky TOC. Items/sections: site-items.css. Demos and dialogs: site-demos.css. */
:root{
  --bg:#0F1113;--panel:#171A1D;--panel2:#1E2226;--ink:#EEF0EE;--mute:#9AA3A8;--line:#2A2F34;
  --lime:#B8FF3B;--lime300:#D4FF85;--on-lime:#0F1113;--lime-text:#B8FF3B;--danger:#FF7A6B;
  --pill-gray:#2A2F34;--focus:#D4FF85;--toc-bg:rgba(15,17,19,.92);
  --paper:#F6F0E3;--paper-ink:#1E1A14;--paper-shadow:#000;
  --r:12px;--r2:8px;
  --sans:"Space Grotesk",system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;
  --mono:"JetBrains Mono",ui-monospace,SFMono-Regular,Consolas,monospace;
  --gutter:16px;--maxw:1180px;color-scheme:dark;
}
:root[data-theme="light"]{
  --bg:#F3F4F0;--panel:#FFFFFF;--panel2:#ECEEE8;--ink:#13171A;--mute:#4D585E;--line:#CDD3CD;
  --lime-text:#3F5A08;--danger:#A8281E;--pill-gray:#DDE1DB;--focus:#1F5FE0;--toc-bg:rgba(243,244,240,.93);
  --paper-shadow:#1E1A14;color-scheme:light;
}
@media (prefers-color-scheme:light){
  :root:not([data-theme="dark"]){
    --bg:#F3F4F0;--panel:#FFFFFF;--panel2:#ECEEE8;--ink:#13171A;--mute:#4D585E;--line:#CDD3CD;
    --lime-text:#3F5A08;--danger:#A8281E;--pill-gray:#DDE1DB;--focus:#1F5FE0;--toc-bg:rgba(243,244,240,.93);
    --paper-shadow:#1E1A14;color-scheme:light;
  }
}
*,*::before,*::after{box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-text-size-adjust:100%}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}}
body{margin:0;background:var(--bg);color:var(--ink);font:400 17px/1.6 var(--sans);overflow-wrap:break-word;overflow-x:hidden}
@media (min-width:1024px){:root{--gutter:32px}}
h1,h2,h3{text-wrap:balance;margin:0;line-height:1.12;letter-spacing:-.015em;font-weight:700}
p,li,summary,figcaption{text-wrap:pretty}
p{margin:0}
img{max-width:100%;height:auto;display:block}
a{color:inherit}
code,kbd{font-family:var(--mono)}
:focus-visible{outline:3px solid var(--focus);outline-offset:3px;border-radius:4px}
.wrap{width:100%;max-width:calc(var(--maxw) + 2 * var(--gutter));margin-inline:auto;padding-inline:var(--gutter)}
.skip{position:absolute;left:-999px;top:8px;background:var(--lime);color:var(--on-lime);padding:8px 14px;border-radius:var(--r2);z-index:100}
.skip:focus{left:8px}

/* Buttons */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;padding:8px 16px;border-radius:var(--r2);
  font:600 14px/1 var(--sans);border:1.5px solid var(--line);background:transparent;color:var(--ink);cursor:pointer;text-decoration:none}
.btn:hover{border-color:var(--ink)}
.btn.primary{background:var(--lime);border-color:var(--lime);color:var(--on-lime)}
.btn.primary:hover{background:var(--lime300);border-color:var(--lime300)}
.btn.done{background:var(--lime300);color:var(--on-lime);border-color:var(--lime300)}

/* Header (always dark: the lockup is drawn for a dark ground) */
.site-header{background:#0F1113;color:#EEF0EE;border-bottom:1px solid #2A2F34}
.site-header .wrap{display:flex;align-items:center;gap:12px 20px;flex-wrap:wrap;padding-block:14px}
.lockup{height:30px;width:auto}
.hd-meta{display:flex;gap:6px 16px;flex-wrap:wrap;align-items:center;margin-left:auto;font:500 12px/1.4 var(--mono);letter-spacing:.04em;text-transform:uppercase;color:#9AA3A8}
.hd-meta time{color:#EEF0EE}
.theme-toggle{min-height:44px;min-width:44px;padding:0 12px;border-radius:var(--r2);border:1.5px solid #3A4147;background:transparent;color:#EEF0EE;font:600 13px/1 var(--sans);cursor:pointer;display:inline-flex;align-items:center;justify-content:center;gap:8px}
.theme-toggle:hover{border-color:#EEF0EE}
.theme-toggle svg{width:18px;height:18px;fill:none;stroke:currentColor;stroke-width:2}
.site-header :focus-visible{outline-color:#D4FF85}
@media (max-width:600px){.hd-meta{order:3;margin-left:0;width:100%}.theme-toggle{margin-left:auto}}

/* Hero */
.hero{padding-block:40px 48px}
.hero-grid{display:grid;gap:32px;align-items:center}
.kicker{font:600 12px/1.4 var(--mono);letter-spacing:.08em;text-transform:uppercase;color:var(--lime-text);margin-bottom:14px}
.hero h1{font-size:clamp(32px,6.6vw,64px);letter-spacing:-.025em;line-height:1.04}
.hero-lead{margin-top:18px;font-size:clamp(17px,2vw,20px);color:var(--mute);max-width:56ch}
.stats{list-style:none;margin:28px 0 0;padding:0;display:grid;gap:12px}
.stat{background:var(--panel);border:1px solid var(--line);border-radius:var(--r);padding:14px 16px;display:grid;grid-template-columns:auto 1fr;gap:4px 16px;align-items:center}
.stat-v{font:700 30px/1 var(--mono);color:var(--lime-text);letter-spacing:-.03em;min-width:3.4ch}
.stat-l{font-size:15px;line-height:1.4;color:var(--ink)}
@media (min-width:1024px){
  .hero{padding-block:56px 64px}
  .hero-grid{grid-template-columns:minmax(0,1fr) minmax(0,1.05fr);gap:48px}
  .stats{grid-template-columns:repeat(3,1fr)}
  .stat{grid-template-columns:1fr;gap:8px;align-content:start}
}

/* Sticky TOC + reading progress */
.toc{position:sticky;top:0;z-index:30;background:var(--toc-bg);backdrop-filter:blur(10px);-webkit-backdrop-filter:blur(10px);border-block:1px solid var(--line)}
.toc-list{display:flex;gap:8px;list-style:none;margin:0 auto;padding:10px var(--gutter);overflow-x:auto;scrollbar-width:none;max-width:calc(var(--maxw) + 2 * var(--gutter))}
.toc-list::-webkit-scrollbar{display:none}
.toc-list a{display:inline-flex;align-items:center;min-height:44px;padding:0 16px;border:1.5px solid var(--line);border-radius:999px;font:600 14px/1 var(--sans);text-decoration:none;white-space:nowrap;color:var(--ink)}
.toc-list a:hover{border-color:var(--ink)}
.toc-list a[aria-current="true"]{background:var(--lime);border-color:var(--lime);color:var(--on-lime)}
.toc-bar{position:absolute;left:0;right:0;bottom:-1px;height:3px;background:var(--lime);transform:scaleX(var(--p,0));transform-origin:left}