body {
  font-family: Arial, sans-serif;
  background-color: #f5f5f5;
  color: #333;
  margin: 0;
  padding: 0;
  text-align: center;
}

header {
  background-color: #4CAF50;
  color: white;
  padding: 2em;
}

main {
  padding: 2em;
}

button {
  padding: 10px 20px;
  font-size: 1rem;
  cursor: pointer;
}

footer {
  background-color: #ddd;
  padding: 1em;
  margin-top: 2em;
}