body {
  font-family: 'Arial', sans-serif;
  background-color: #f5f5f5;
  margin: 0;
  padding: 0;
}

header {
  background-color: #4CAF50;
  color: white;
  text-align: center;
  padding: 1rem;
}

main {
  margin: 2rem;
}

h2 {
  color: #4CAF50;
}

button {
  background-color: #4CAF50;
  color: white;
  border: none;
  padding: 0.5rem 1rem;
  cursor: pointer;
  font-size: 1rem;
}

button:hover {
  background-color: #45a049;
}