:root {
  --bg: #fbfaf7; --card: #ffffff; --ink: #14181f; --muted: #556070; --line: #e1ddd3;
  --accent: #0b6b5e; --accent-ink: #ffffff; --warn: #9a4a07; --warn-bg: #fdf3e6;
  --ok-bg: #e8f5f1;
  --mono: ui-monospace, "SF Mono", "Cascadia Mono", "DejaVu Sans Mono", Menlo, Consolas, monospace;
  --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1318; --card: #151b22; --ink: #e8eaed; --muted: #9aa4b1; --line: #27313b;
    --accent: #43c2a4; --accent-ink: #07211b; --warn: #f0a458; --warn-bg: #2a2014;
    --ok-bg: #12261f;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 17px/1.6 var(--sans); }
.wrap { max-width: 68rem; margin: 0 auto; padding: 0 1.25rem; }
.prose { max-width: 42rem; }
a { color: var(--accent); text-underline-offset: 0.18em; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible, .btn:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; border-radius: 3px; }
.skip { position: absolute; left: -999px; top: 0; background: var(--ink); color: var(--bg); padding: .5rem 1rem; z-index: 10; }
.skip:focus { left: 0; }

header.site { border-bottom: 1px solid var(--line); background: var(--bg); position: sticky; top: 0; z-index: 5; }
.bar { display: flex; align-items: center; gap: 1.25rem; min-height: 3.6rem; flex-wrap: wrap; padding-top: .4rem; padding-bottom: .4rem; }
.brand { font: 700 1.35rem var(--mono); color: var(--ink); text-decoration: none; letter-spacing: -0.02em; margin-right: auto; }
nav { display: flex; gap: 1.1rem; flex-wrap: wrap; }
nav a { color: var(--muted); text-decoration: none; font-size: .95rem; padding: .2rem 0; border-bottom: 2px solid transparent; }
nav a:hover { color: var(--ink); }
nav a[aria-current="page"] { color: var(--ink); border-bottom-color: var(--accent); }

.btn { display: inline-block; background: var(--accent); color: var(--accent-ink); font-weight: 600; text-decoration: none; padding: .7rem 1.2rem; border-radius: 6px; }
.btn:hover { filter: brightness(1.08); }
.btn.small { padding: .35rem .8rem; font-size: .9rem; }
.btn.ghost { background: transparent; color: var(--accent); border: 1.5px solid var(--accent); }

h1, h2, h3 { line-height: 1.2; letter-spacing: -0.015em; margin: 0 0 .6rem; }
h1 { font-size: clamp(2rem, 5vw, 3.1rem); }
h2 { font-size: 1.6rem; margin-top: 3rem; }
h3 { font-size: 1.15rem; margin-top: 1.8rem; }
p { margin: 0 0 1rem; }
.lede { font-size: 1.2rem; color: var(--muted); max-width: 40rem; }
.eyebrow { font: 600 .8rem var(--mono); text-transform: uppercase; letter-spacing: .09em; color: var(--accent); margin-bottom: .8rem; }
section.hero { padding: 4rem 0 2.5rem; }
section.block { padding: .5rem 0 1rem; }
.cta { display: flex; gap: .8rem; flex-wrap: wrap; margin-top: 1.6rem; align-items: center; }
.fine { font-size: .88rem; color: var(--muted); }

.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); gap: 1rem; margin: 1.2rem 0; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 8px; padding: 1.1rem 1.2rem; }
.card h3 { margin-top: 0; font-size: 1.05rem; }
.card p:last-child { margin-bottom: 0; }

table { width: 100%; border-collapse: collapse; margin: 1.2rem 0; font-size: .95rem; background: var(--card); border: 1px solid var(--line); }
caption { text-align: left; font-size: .9rem; color: var(--muted); padding: .4rem 0; caption-side: bottom; }
th, td { text-align: left; vertical-align: top; padding: .65rem .8rem; border-bottom: 1px solid var(--line); }
thead th { font: 600 .78rem var(--mono); text-transform: uppercase; letter-spacing: .05em; color: var(--muted); background: var(--bg); }
tbody th { font-weight: 600; }
td.num { font: 700 1.05rem var(--mono); white-space: nowrap; }
td.na { color: var(--muted); }
.sub { display: block; font-size: .82rem; color: var(--muted); margin-top: .15rem; font-weight: 400; }
.tablewrap { overflow-x: auto; }

.callout { border-left: 4px solid var(--accent); background: var(--ok-bg); padding: .9rem 1.1rem; border-radius: 0 6px 6px 0; margin: 1.4rem 0; }
.callout.warn { border-left-color: var(--warn); background: var(--warn-bg); }
.callout p:last-child { margin-bottom: 0; }

ul.ticks, ul.dots { padding-left: 0; list-style: none; margin: .6rem 0 1.2rem; }
ul.ticks li, ul.dots li { padding-left: 1.7rem; position: relative; margin-bottom: .45rem; }
ul.ticks li::before { content: "✓"; position: absolute; left: 0; color: var(--accent); font-weight: 700; }
ul.dots li::before { content: "○"; position: absolute; left: 0; color: var(--muted); }

.stat { font: 700 2.1rem var(--mono); letter-spacing: -0.03em; line-height: 1.1; }
.statlabel { font-size: .9rem; color: var(--muted); }

figure { margin: 1.6rem 0; }
figure svg { width: 100%; height: auto; max-width: 46rem; display: block; }
figcaption { font-size: .88rem; color: var(--muted); margin-top: .5rem; max-width: 46rem; }
svg .box { fill: var(--card); stroke: var(--line); stroke-width: 1.5; }
svg .az { fill: none; stroke: var(--line); stroke-width: 1.5; stroke-dasharray: 5 5; }
svg .node { fill: var(--ok-bg); stroke: var(--accent); stroke-width: 2; }
svg .arb { fill: var(--card); stroke: var(--muted); stroke-width: 2; stroke-dasharray: 4 3; }
svg text { fill: var(--ink); font: 600 13px var(--mono); }
svg .small { font: 400 11.5px var(--mono); fill: var(--muted); }
svg .link { stroke: var(--accent); stroke-width: 2; fill: none; }
svg .linkm { stroke: var(--muted); stroke-width: 1.5; fill: none; stroke-dasharray: 3 4; }

footer.site { border-top: 1px solid var(--line); margin-top: 4rem; padding: 2rem 0 3rem; }
@media (max-width: 40rem) {
  body { font-size: 16px; }
  section.hero { padding-top: 2.4rem; }
  th, td { padding: .5rem .55rem; }
}
@media (prefers-reduced-motion: no-preference) { .btn { transition: filter .15s; } }
.fine.tight { margin-top: 1rem; }
@media (max-width: 40rem) { header.site { position: static; } }

/* Architecture section */
nav.subnav { display: flex; gap: .4rem .9rem; flex-wrap: wrap; padding: .6rem 0; border-bottom: 1px solid var(--line); margin-top: 1.4rem; }
nav.subnav a { font-size: .88rem; }
nav.subnav a[aria-current="page"], nav.subnav a[aria-current="true"] { color: var(--ink); border-bottom-color: var(--accent); }
.diagram { overflow-x: auto; }
.diagram svg { min-width: 600px; }
svg .bad { fill: var(--warn-bg); stroke: var(--warn); stroke-width: 2; }
svg .linkw { stroke: var(--warn); stroke-width: 2; fill: none; stroke-dasharray: 5 4; }
svg .arrow { fill: var(--accent); }
svg .arrowm { fill: var(--muted); }
svg .arroww { fill: var(--warn); }
svg .warn { fill: var(--warn); }
svg .tick { stroke: var(--muted); stroke-width: 1.5; }
.tag { font: 600 .7rem var(--mono); text-transform: uppercase; letter-spacing: .05em; padding: .08rem .4rem; border: 1px solid var(--line); border-radius: 4px; color: var(--muted); white-space: nowrap; }
.tag.measured { border-color: var(--accent); color: var(--accent); }
.tag.approx { border-color: var(--warn); color: var(--warn); }
.tag.design { border-color: var(--muted); }
.card a.more { font-weight: 600; }
.glossary td:first-child, .glossary th:first-child { white-space: nowrap; }
pre { background: var(--card); border: 1px solid var(--line); border-radius: 6px; padding: .9rem 1rem; overflow-x: auto; font: .88rem/1.55 var(--mono); max-width: 46rem; margin: 1rem 0; }
pre code { font: inherit; }
nav.subnav + nav.subnav { margin-top: 0; padding-left: 1rem; border-left: 3px solid var(--line); border-bottom: 0; }