:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --text: #1d2321;
  --muted: #5b6662;
  --line: #e4e1d9;
  --accent: #0f6b52;
  --accent-soft: #e5f2ed;
  --note: #fff6df;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121615;
    --surface: #1a1f1e;
    --text: #e8ece9;
    --muted: #a3ada9;
    --line: #2d3432;
    --accent: #5cc7a4;
    --accent-soft: #1d2f29;
    --note: #2b2716;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.65 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}
a { color: var(--accent); }
a:hover { text-decoration-thickness: 2px; }
.wrap { max-width: 1040px; margin: 0 auto; padding: 0 16px; }
.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 8px; background: var(--surface); padding: 8px; }

.site-header { border-bottom: 1px solid var(--line); background: var(--surface); }
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding-top: 14px; padding-bottom: 14px; flex-wrap: wrap; }
.brand { font-weight: 700; font-size: 1.2rem; color: var(--text); text-decoration: none; letter-spacing: -0.01em; }
.logo { color: var(--accent); }
nav a { margin-left: 18px; color: var(--muted); text-decoration: none; font-size: 0.95rem; }
nav a:first-child { margin-left: 0; }
nav a:hover { color: var(--accent); }

main { padding-top: 32px; padding-bottom: 48px; }
h1, h2, h3 { line-height: 1.25; letter-spacing: -0.015em; }
h1 { font-size: clamp(1.8rem, 4vw, 2.5rem); margin: 0 0 12px; }
h2 { font-size: 1.45rem; margin-top: 2.2em; }
h3 { font-size: 1.15rem; }

.hero { padding: 24px 0 8px; max-width: 720px; }
.lede { font-size: 1.15rem; color: var(--muted); }
.btn { display: inline-block; background: var(--accent); color: var(--bg); padding: 10px 18px; border-radius: 8px; text-decoration: none; font-weight: 600; margin: 4px 8px 4px 0; }
.btn.ghost { background: transparent; color: var(--accent); border: 1px solid var(--accent); }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 16px; }
.card { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 18px 20px; }
.card h3 { margin: 4px 0 8px; }
.card h3 a { color: var(--text); text-decoration: none; }
.card h3 a:hover { color: var(--accent); }
.card p { margin: 0 0 8px; color: var(--muted); font-size: 0.95rem; }
.eyebrow { text-transform: uppercase; font-size: 0.75rem !important; letter-spacing: 0.08em; color: var(--accent) !important; font-weight: 700; }
.meta { color: var(--muted); font-size: 0.88rem; }
.topic-list { padding-left: 1.1em; }
.topic-list li { margin-bottom: 8px; }

.post { max-width: 720px; }
.crumbs { font-size: 0.85rem; color: var(--muted); margin-bottom: 12px; }
.crumbs a { color: var(--muted); }
.prose table { width: 100%; border-collapse: collapse; margin: 1.2em 0; font-size: 0.95rem; display: block; overflow-x: auto; }
.prose th, .prose td { border: 1px solid var(--line); padding: 8px 10px; text-align: left; vertical-align: top; }
.prose th { background: var(--accent-soft); }
.prose blockquote, .callout { margin: 1.4em 0; padding: 14px 18px; background: var(--accent-soft); border-left: 4px solid var(--accent); border-radius: 0 8px 8px 0; }
.note { margin-top: 32px; padding: 14px 18px; background: var(--note); border-radius: 8px; font-size: 0.93rem; }
.related { margin-top: 48px; }

.calc { background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 20px; margin: 20px 0; }
.calc label { display: block; font-weight: 600; margin: 12px 0 4px; }
.calc input, .calc select { width: 100%; padding: 10px; font-size: 1rem; border: 1px solid var(--line); border-radius: 8px; background: var(--bg); color: var(--text); }
.calc output { display: block; }
.result-row { display: flex; justify-content: space-between; gap: 12px; border-bottom: 1px dashed var(--line); padding: 8px 0; }
.result-row.total { font-weight: 700; border-bottom: none; }

.site-footer { border-top: 1px solid var(--line); background: var(--surface); padding: 28px 0; color: var(--muted); }
.small { font-size: 0.85rem; }
.footer-nav a { margin: 0 14px 6px 0; display: inline-block; }