body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background-color: #f4f8f4;
  color: #333;
}

header {
  background-color: #2d6a4f;
  color: white;
  text-align: center;
  padding: 1.5rem;
}

main {
  max-width: 500px;
  margin: 2rem auto;
  back