body {
  font-family: system-ui, sans-serif;
  margin: 0;
  padding: 0;
  color: #222;
  background: #fafafa;
}

header {
  background: #2f6f4f;
  color: white;
  padding: 2rem 1rem;
  text-align: center;
}

main {
  max-width: 640px;
  margin: 2rem auto;
  padding: 0 1rem;
}

footer {
  text-align: center;
  padding: 1rem;
  color: #666;
  font-size: 0.9rem;
}