body {
  font-family: system-ui, sans-serif;
  max-width: 800px;
  margin: 0 auto;
  padding: 2rem;
  background-color: #f9f9f9;
  color: #333;
}

header h1 {
  color: #111;
}

button {
  padding: 0.5rem 1rem;
  border: none;
  background-color: #0070f3;
  color: white;
  border-radius: 4px;
  cursor: pointer;
}