:root {
  --bg: #f7f8fa; --fg: #16191f; --muted: #586172; --rule: #dfe3ea; --card: #ffffff;
  --accent: #0e7490; --accent2: #b45309; --code-bg: #eef1f5; --mark: #fef3c7;
  --node: #0e7490; --node2: #7c3aed; --node3: #b45309; --wire: #a8b3c4; --grid: #e7ebf1;
  --ok: #15803d; --area: rgba(14, 116, 144, 0.16);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #0d1117; --fg: #e6e9ef; --muted: #9aa4b2; --rule: #232a35; --card: #141a23;
    --accent: #22d3ee; --accent2: #fbbf24; --code-bg: #18202b; --mark: #3b2f10;
    --node: #22d3ee; --node2: #a78bfa; --node3: #fbbf24; --wire: #3c4757; --grid: #1b2330;
    --ok: #4ade80; --area: rgba(34, 211, 238, 0.16);
  }
}
:root[data-theme="dark"] {
  --bg: #0d1117; --fg: #e6e9ef; --muted: #9aa4b2; --rule: #232a35; --card: #141a23;
  --accent: #22d3ee; --accent2: #fbbf24; --code-bg: #18202b; --mark: #3b2f10;
  --node: #22d3ee; --node2: #a78bfa; --node3: #fbbf24; --wire: #3c4757; --grid: #1b2330;
  --ok: #4ade80; --area: rgba(34, 211, 238, 0.16);
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--fg); font: 17px/1.65 Inter, system-ui, sans-serif; }
main { max-width: 760px; margin: 0 auto; padding: 48px 16px 96px; }
header.top { border-bottom: 1px solid var(--rule); padding-bottom: 28px; margin-bottom: 32px; }
.kicker { font: 600 13px/1 "JetBrains Mono", monospace; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); }
h1 { font-size: clamp(32px, 6vw, 46px); line-height: 1.1; margin: 14px 0 14px; letter-spacing: -0.02em; }
.lede { font-size: 19px; color: var(--muted); margin: 0; }
h2 { font-size: 26px; margin: 56px 0 10px; letter-spacing: -0.01em; scroll-margin-top: 64px; }
h2 .n { color: var(--accent); font: 600 15px "JetBrains Mono", monospace; margin-right: 10px; vertical-align: 3px; }
h3 { font-size: 18px; margin: 30px 0 6px; scroll-margin-top: 64px; }
p { margin: 12px 0; }
a { color: var(--accent); text-underline-offset: 2px; }
code, .mono { font-family: "JetBrains Mono", monospace; }
code { background: var(--code-bg); padding: 1px 5px; border-radius: 4px; font-size: 0.88em; }
.toc { background: var(--card); border: 1px solid var(--rule); border-radius: 10px; padding: 14px 18px; font-size: 15px; }
.toc ol { margin: 6px 0 0; padding-left: 20px; columns: 2; column-gap: 28px; }
@media (max-width: 560px) { .toc ol { columns: 1; } }
.toc li { margin: 2px 0; break-inside: avoid; }
figure { margin: 26px 0; }
figure svg { width: 100%; height: auto; display: block; background: var(--card); border: 1px solid var(--rule); border-radius: 10px; }
figcaption { font-size: 14px; color: var(--muted); margin-top: 8px; }
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 12px; margin: 26px 0 8px; }
.stat { background: var(--card); border: 1px solid var(--rule); border-radius: 10px; padding: 14px 16px; }
.stat b { display: block; font: 700 26px/1.15 "JetBrains Mono", monospace; color: var(--accent); letter-spacing: -0.02em; }
.stat span { display: block; font-size: 14px; color: var(--muted); margin-top: 6px; line-height: 1.45; }
.callout { border-left: 3px solid var(--accent); background: var(--card); padding: 12px 16px; border-radius: 0 8px 8px 0; margin: 20px 0; }
.callout b { display: block; margin-bottom: 2px; }
.callout.amber { border-color: var(--accent2); }
ul.tight { padding-left: 20px; } ul.tight li { margin: 4px 0; }
.lanes { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; margin: 18px 0; }
.lane { background: var(--card); border: 1px solid var(--rule); border-radius: 10px; padding: 10px 12px; font-size: 14.5px; }
.lane b { display: block; font: 600 13px "JetBrains Mono", monospace; color: var(--accent); text-transform: uppercase; letter-spacing: .06em; }
.lesson { background: var(--card); border: 1px solid var(--rule); border-radius: 12px; padding: 4px 18px 10px; margin: 18px 0; }
.lesson h3 { margin-top: 16px; }
.lesson h3 .n { font: 600 13px "JetBrains Mono", monospace; color: var(--accent2); margin-right: 8px; }
.lesson .rule { font-size: 15px; border-top: 1px dashed var(--rule); padding-top: 8px; margin-top: 10px; color: var(--muted); }
.lesson .rule b { color: var(--fg); }
.fig-num { font-family: "JetBrains Mono", monospace; font-weight: 600; white-space: nowrap; }
footer { border-top: 1px solid var(--rule); margin-top: 64px; padding-top: 20px; font-size: 14.5px; color: var(--muted); }
.theme { position: absolute; top: 12px; right: 12px; font: 600 12px "JetBrains Mono", monospace; background: var(--card); color: var(--fg); border: 1px solid var(--rule); border-radius: 999px; padding: 6px 12px; cursor: pointer; }
.theme:focus-visible, a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
/* the fleet map */
.wire { stroke: var(--wire); stroke-width: 2; fill: none; }
.pulse { stroke: var(--accent); stroke-width: 2.5; fill: none; stroke-dasharray: 6 14; animation: flow 2.4s linear infinite; }
@keyframes flow { to { stroke-dashoffset: -40; } }
@media (prefers-reduced-motion: reduce) { .pulse { animation: none; } }
.node-c { fill: var(--card); stroke: var(--node); stroke-width: 2.5; }
.node-w { fill: var(--card); stroke: var(--node2); stroke-width: 2; }
.node-t { fill: var(--card); stroke: var(--node3); stroke-width: 2; }
.lbl { fill: var(--fg); font: 600 13px Inter, system-ui, sans-serif; }
.sub { fill: var(--muted); font: 12px Inter, system-ui, sans-serif; }
.grid { stroke: var(--grid); stroke-width: 1; }
.avg { stroke: var(--accent); stroke-width: 2; fill: none; }
.peak { fill: var(--area); stroke: none; }
.axis { fill: var(--muted); font: 12px Inter, system-ui, sans-serif; }
.rung { fill: var(--card); stroke: var(--wire); stroke-width: 1.5; }
.rung.home { stroke: var(--accent); stroke-width: 2.5; }
.rung.job { stroke: var(--accent2); stroke-width: 2.5; }

/* --- v2: nav, history, dashboard --- */
:root { --l1: #0e7490; --l2: #7c3aed; --l3: #b45309; --l4: #64748b; --bar: #0e7490; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) { --l1: #22d3ee; --l2: #a78bfa; --l3: #fbbf24; --l4: #94a3b8; --bar: #22d3ee; } }
:root[data-theme="dark"] { --l1: #22d3ee; --l2: #a78bfa; --l3: #fbbf24; --l4: #94a3b8; --bar: #22d3ee; }
.topnav { position: sticky; top: 0; z-index: 5; background: var(--bg); border-bottom: 1px solid var(--rule); }
.topnav .in { max-width: 1080px; margin: 0 auto; padding: 10px 16px; display: flex; gap: 6px 18px; align-items: center; flex-wrap: wrap; font-size: 14.5px; }
.topnav .brand { font: 700 14px "JetBrains Mono", monospace; letter-spacing: .06em; text-transform: uppercase; color: var(--accent); margin-right: auto; text-decoration: none; }
.topnav a { color: var(--fg); text-decoration: none; padding: 4px 2px; border-bottom: 2px solid transparent; }
.topnav a[aria-current="page"], .topnav a:hover { border-bottom-color: var(--accent); }
.topnav .theme { position: static; }
.wide { max-width: 1080px; }
.timeline { list-style: none; padding: 0; margin: 18px 0; border-left: 2px solid var(--rule); }
.timeline li { position: relative; padding: 0 0 14px 22px; }
.timeline li::before { content: ""; position: absolute; left: -7px; top: 7px; width: 12px; height: 12px; border-radius: 50%; background: var(--card); border: 2px solid var(--accent); }
.timeline .d { font: 600 13px "JetBrains Mono", monospace; color: var(--muted); }
.timeline b { display: block; }
.bars rect { fill: var(--bar); }
.bars .ms { fill: var(--accent2); }
.dash { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 14px; margin: 18px 0; }
.card { background: var(--card); border: 1px solid var(--rule); border-radius: 12px; padding: 14px 16px 10px; min-width: 0; }
.card h3 { margin: 0; font-size: 16px; }
.card p { margin: 4px 0 8px; font-size: 13.5px; color: var(--muted); }
.card svg { width: 100%; height: auto; display: block; }
.stack { display: flex; height: 26px; border-radius: 6px; overflow: hidden; border: 1px solid var(--rule); margin: 10px 0; }
.stack span { display: block; height: 100%; }
.legend { list-style: none; padding: 0; margin: 6px 0 0; display: grid; grid-template-columns: repeat(auto-fit, minmax(160px, 1fr)); gap: 6px 14px; font-size: 14.5px; }
.legend li { display: flex; align-items: center; gap: 8px; }
.legend i { width: 12px; height: 12px; border-radius: 3px; display: inline-block; flex: none; }
.legend .pct { margin-left: auto; font-family: "JetBrains Mono", monospace; }
.l1 { background: var(--l1); } .l2 { background: var(--l2); } .l3 { background: var(--l3); } .l4 { background: var(--l4); }
.note { font-size: 14px; color: var(--muted); }