body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  background-color: #f4f4f4;
}

header {
  text-align: center;
  padding: 20px;
  background-color: #333;
  color: #fff;
}

main {
  padding: 20px;
  max-width: 800px;
  background-color: #fff;
  border-radius: 8px;
}