:root {
  --bg: #ffffff;
  --fg: #1e293b;
  --muted: #64748b;
  --primary: #4f46e5;
  --border: #e2e8f0;
  --max: 760px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.7;
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
.container { max-width: var(--max); margin: 0 auto; padding: 2.5rem 1.25rem 4rem; }
.site-header {
  display: flex; align-items: center; justify-content: space-between; gap: 1rem;
  max-width: var(--max); margin: 0 auto; padding: 1.1rem 1.25rem;
  border-bottom: 1px solid var(--border);
}
.logo { font-weight: 700; font-size: 1.15rem; color: var(--fg); text-decoration: none; letter-spacing: -0.02em; }
.site-header nav { display: flex; gap: 1.1rem; flex-wrap: wrap; }
.site-header nav a { color: var(--muted); text-decoration: none; font-size: 0.95rem; font-weight: 500; }
.site-header nav a:hover { color: var(--primary); }
.prose h1 { font-size: 2rem; line-height: 1.2; letter-spacing: -0.03em; margin: 0 0 1rem; }
.prose h2 { font-size: 1.45rem; margin: 2rem 0 0.75rem; letter-spacing: -0.02em; }
.prose h3 { font-size: 1.15rem; margin: 1.5rem 0 0.5rem; }
.prose p { margin: 0 0 1rem; }
.prose a { color: var(--primary); }
.prose ul, .prose ol { padding-left: 1.25rem; }
.prose img { max-width: 100%; height: auto; border-radius: 10px; }
.prose code { background: #f1f5f9; padding: 0.1rem 0.35rem; border-radius: 5px; font-size: 0.9em; }
.prose blockquote { border-left: 3px solid var(--primary); margin: 1.25rem 0; padding: 0.25rem 0 0.25rem 1rem; color: var(--muted); }
.btn {
  display: inline-block; background: var(--primary); color: #fff; text-decoration: none;
  padding: 0.7rem 1.4rem; border-radius: 8px; font-weight: 600; margin-top: 0.5rem;
}
.site-footer { max-width: var(--max); margin: 0 auto; padding: 1.5rem 1.25rem; border-top: 1px solid var(--border); color: var(--muted); font-size: 0.9rem; }