:root {
  --bg: #fbfaf7;
  --fg: #1c1e21;
  --muted: #5d636b;
  --rule: #e3e0d8;
  --accent: #0b6e69;
  --accent-soft: #e2f0ee;
  --surface: #ffffff;
  --faint: #868c93;
  --signal: #b65d0c;
  --code-bg: #10191c;
  --code-ink: #d7e3e6;
  --serif: "Source Serif 4", Georgia, serif;
  --sans: "IBM Plex Sans", system-ui, sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14171a;
    --fg: #e6e4df;
    --muted: #9aa1a8;
    --rule: #2a2f34;
    --accent: #5cc6bd;
    --accent-soft: #17302e;
    --surface: #1a1e22;
    --faint: #7a828a;
    --signal: #f0a050;
    --code-bg: #0b1114;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 400 1.0625rem/1.65 var(--sans);
  min-height: 100vh; display: flex; flex-direction: column;
}
.wrap { max-width: 42rem; margin: 0 auto; padding: 0 1rem; }
a { color: var(--accent); text-underline-offset: 0.15em; }

.site-header { border-bottom: 1px solid var(--rule); }
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; padding-block: 1rem; flex-wrap: wrap;
}
.brand {
  font: 500 0.95rem var(--mono); letter-spacing: 0.02em;
  color: var(--fg); text-decoration: none;
  display: inline-flex; align-items: center; gap: 0.55rem;
}
.mark {
  width: 0.9rem; height: 0.9rem; border-radius: 50%;
  border: 2px solid var(--accent);
  box-shadow: 0 0 0 3px var(--bg), 0 0 0 5px var(--accent-soft);
}
nav { display: flex; gap: 1.25rem; font-size: 0.9rem; }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover { color: var(--fg); }

main.wrap { padding-block: 3rem 4rem; flex: 1; width: 100%; }

.intro h1 {
  font: 600 clamp(1.8rem, 5vw, 2.4rem)/1.15 var(--serif);
  margin: 0 0 0.75rem; letter-spacing: -0.01em;
}
.intro p { color: var(--muted); margin: 0 0 2.5rem; }

.topic-nav {
  display: flex; flex-wrap: wrap; gap: 0.5rem; margin: 0 0 1.5rem;
  font: 500 0.85rem/1 var(--sans);
}
.topic-nav a {
  color: var(--muted); text-decoration: none;
  border: 1px solid var(--rule); border-radius: 999px; padding: 0.45rem 0.8rem;
}
.topic-nav a:hover { color: var(--fg); border-color: var(--faint); }
.topic-nav a[aria-current="page"] { color: var(--accent); background: var(--accent-soft); border-color: var(--accent); }

.post-list { list-style: none; padding: 0; margin: 0; }
.post-list .post-meta { margin: 0; display: flex; flex-wrap: wrap; gap: 0.35rem 0.9rem; align-items: baseline; }
.post-list .topic-label { font: 500 0.8rem var(--mono); text-transform: uppercase; letter-spacing: 0.06em; text-decoration: none; }
.post-list .topic-label:hover { text-decoration: underline; }
.post-list .empty { color: var(--muted); }
.post-list li { padding-block: 1.5rem; border-top: 1px solid var(--rule); }
.post-list time, .meta, .kicker {
  font: 500 0.8rem var(--mono); color: var(--muted);
  text-transform: uppercase; letter-spacing: 0.06em;
}
.post-list h2 { font: 600 1.4rem/1.25 var(--serif); margin: 0.35rem 0 0.4rem; }
.post-list h2 a { color: var(--fg); text-decoration: none; }
.post-list h2 a:hover { color: var(--accent); }
.post-list p { margin: 0; color: var(--muted); }

.post header { margin-bottom: 2rem; }
.kicker { color: var(--accent); margin: 0 0 0.6rem; }
.kicker a { color: inherit; text-decoration: none; }
.kicker a:hover { text-decoration: underline; }
.post h1 {
  font: 600 clamp(1.9rem, 5.5vw, 2.6rem)/1.15 var(--serif);
  margin: 0 0 0.75rem; letter-spacing: -0.015em;
}
.post .meta { margin: 0; text-transform: none; letter-spacing: 0.01em; }
.tags { margin: 0 0 0.8rem; display: flex; gap: 0.4rem; flex-wrap: wrap; }
.tags span {
  font: 500 0.72rem/1 var(--mono); text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--accent); background: var(--accent-soft); padding: 0.35rem 0.5rem; border-radius: 4px;
}
.dek { font: 400 1.25rem/1.5 var(--serif); color: var(--muted); margin: 0 0 1rem; }
.post-foot { margin-top: 3rem; padding-top: 1.2rem; border-top: 1px solid var(--rule); font-size: 0.95rem; }

.prose { font: 400 1.15rem/1.7 var(--serif); }
.prose h2 { font: 600 1.15rem/1.3 var(--sans); margin: 2.5rem 0 0.5rem; }
.prose h3 { font: 600 1rem/1.35 var(--sans); margin: 2rem 0 0.4rem; }
.prose h2 a, .prose h3 a { color: inherit; text-decoration: none; }
.prose h2 a:hover::after, .prose h3 a:hover::after { content: " #"; color: var(--faint); }
.prose strong { font-weight: 600; }
.prose hr { border: 0; border-top: 1px solid var(--rule); margin: 2.5rem 0; }
.prose p, .prose ul, .prose ol { margin: 0 0 1.15rem; }
.prose li { margin-bottom: 0.4rem; }
.prose em:first-child:only-child { color: var(--muted); }
.prose :not(pre) > code { font: 0.86em var(--mono); background: var(--accent-soft); padding: 0.1em 0.35em; border-radius: 4px; overflow-wrap: anywhere; }
.prose pre { background: var(--code-bg); color: var(--code-ink); border-radius: 8px; padding: 1rem 1.1rem; overflow-x: auto; font: 0.82rem/1.6 var(--mono); margin: 0 0 1.15rem; }
.prose pre code { font: inherit; background: none; padding: 0; }
.prose blockquote { margin: 1.5rem 0; padding-left: 1rem; border-left: 3px solid var(--accent); color: var(--muted); }
.prose img, .prose svg { max-width: 100%; height: auto; }

/* tables */
.prose .table-wrap { overflow-x: auto; margin: 0 -1rem 1.15rem; padding: 0 1rem; }
.prose table { width: 100%; border-collapse: collapse; font: 0.8rem/1.45 var(--mono); }
.prose th, .prose td { text-align: left; padding: 0.5rem 0.6rem; border-bottom: 1px solid var(--rule); vertical-align: top; }
.prose th { font: 600 0.8rem var(--sans); color: var(--muted); border-bottom: 2px solid var(--faint); }
.prose td.num, .prose th.num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.prose tr.hl td { background: var(--accent-soft); font-weight: 600; }

/* callouts and stat tiles */
.callout { background: var(--surface); border: 1px solid var(--rule); border-left: 4px solid var(--signal); border-radius: 8px; padding: 1rem 1.2rem; font-size: 1rem; margin: 0 0 1.15rem; }
.callout > :last-child { margin-bottom: 0; }
.callout-title { font: 600 0.75rem/1 var(--mono); text-transform: uppercase; letter-spacing: 0.08em; color: var(--signal); margin: 0 0 0.55rem !important; }
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(8.5rem, 1fr)); gap: 0.75rem; margin: 1.8rem 0; }
.stat { background: var(--surface); border: 1px solid var(--rule); border-radius: 8px; padding: 0.9rem 1rem; }
.stat b { display: block; font: 600 1.5rem/1.1 var(--sans); letter-spacing: -0.02em; color: var(--accent); font-variant-numeric: tabular-nums; }
.stat span { display: block; font: 400 0.84rem/1.4 var(--sans); color: var(--muted); margin-top: 0.3rem; }

/* figures and SVG diagrams */
.prose figure { margin: 2rem 0; }
.prose figure.diagram { background: var(--surface); border: 1px solid var(--rule); border-radius: 10px; padding: 1rem; }
.prose figcaption { font: 400 0.88rem/1.5 var(--sans); color: var(--faint); margin-top: 0.7rem; }
.dg-box { fill: var(--bg); stroke: var(--faint); stroke-width: 1.2; }
.dg-box.key { fill: var(--accent-soft); stroke: var(--accent); stroke-width: 1.6; }
.dg-zone { fill: none; stroke: var(--rule); stroke-width: 1.2; stroke-dasharray: 4 4; }
.dg-t { fill: var(--fg); font: 600 13px var(--sans); }
.dg-s { fill: var(--muted); font: 400 11px var(--mono); }
.dg-z { fill: var(--faint); font: 600 10px var(--mono); letter-spacing: 0.08em; text-transform: uppercase; }
.dg-line { stroke: var(--muted); stroke-width: 1.4; fill: none; }
.dg-arrow { fill: var(--muted); }

/* syntax highlighting (code blocks are always dark) */
.token.comment, .token.prolog { color: #6f8a92; font-style: italic; }
.token.string, .token.attr-value { color: #9fd8a4; }
.token.keyword, .token.builtin, .token.important { color: #7fc8f8; }
.token.number, .token.boolean { color: #f0b46a; }
.token.function, .token.class-name { color: #e8d48a; }
.token.operator, .token.punctuation { color: #9aaab0; }
.token.variable, .token.parameter { color: #e7a0c4; }

.site-footer { border-top: 1px solid var(--rule); }
.site-footer .wrap { padding-block: 1.5rem; font-size: 0.85rem; color: var(--muted); }