body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  margin: 0;
  padding: 2rem;
  background: #f4f6f8;
  color: #111;
}

header {
  border-bottom: 1px solid #ddd;
  margin-bottom: 2rem;
}

h1 { margin: 0; }

.tagline { color: #555; }

main section { margin-bottom: 2rem; }

footer {
  border-top: 1px solid #ddd;
  padding-top: 1rem;
  font-size: 0.9rem;
  color: #666;
}