:root {
  --ink: #0f172a;
  --ink-soft: #334155;
  --bg: #fafaf9;
  --bg-section: #fff;
  --accent: #1e40af;
  --accent-soft: #eff6ff;
  --warn: #92400e;
  --max-width: 800px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", system-ui, sans-serif;
  line-height: 1.6;
  font-size: 16px;
}

header, main, footer {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem 1.25rem;
}

header {
  border-bottom: 1px solid #e7e5e4;
}

header h1 {
  margin: 0 0 0.25rem 0;
  font-size: 2rem;
  letter-spacing: -0.02em;
}

.tagline {
  margin: 0.25rem 0 0 0;
  color: var(--ink-soft);
  font-size: 1.1rem;
}

main section {
  background: var(--bg-section);
  border: 1px solid #e7e5e4;
  border-radius: 8px;
  padding: 1.25rem 1.5rem;
  margin: 1rem 0;
}

main h2 {
  margin: 0 0 0.75rem 0;
  font-size: 1.25rem;
  letter-spacing: -0.01em;
}

main p, main li {
  font-size: 1rem;
}

ul { margin-top: 0.25rem; padding-left: 1.25rem; }
li { margin-bottom: 0.25rem; }

a {
  color: var(--accent);
}

a:hover { text-decoration: underline; }

code {
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 0.92em;
  background: #f5f5f4;
  padding: 0.05em 0.3em;
  border-radius: 3px;
}

p.note, p.caveat {
  background: #fef3c7;
  border-left: 3px solid var(--warn);
  padding: 0.75rem 1rem;
  margin: 1rem 0 0 0;
  border-radius: 0 4px 4px 0;
}

p.small {
  color: var(--ink-soft);
  font-size: 0.9rem;
}

.cta-row {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.cta-row a.btn {
  display: inline-block;
  padding: 0.55rem 1rem;
  background: var(--accent);
  color: #fff;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 500;
}

.cta-row a.btn:hover {
  background: #1e3a8a;
  text-decoration: none;
}

.cta-row a.btn.secondary {
  background: #fff;
  color: var(--accent);
  border: 1px solid var(--accent);
}

.toc {
  background: var(--accent-soft);
  border: 1px solid #dbe7ff;
  padding: 0.75rem 1.25rem;
  border-radius: 6px;
  margin-bottom: 1.5rem;
}

.toc ol { margin: 0.25rem 0 0 1.25rem; padding: 0; }
.toc li { margin-bottom: 0.15rem; }

footer {
  border-top: 1px solid #e7e5e4;
  font-size: 0.92rem;
  color: var(--ink-soft);
  padding-bottom: 3rem;
}

footer p { margin: 0.25rem 0; }