body {
  margin: 0;
  font-family: "Arial", sans-serif;
  background-color: #f4f4f4;
  color: #333;
}

main {
  padding: 40px;
  text-align: center;
}

main h2 {
  font-size: 3em;
}

main h3 {
  font-size: 2em;
}

main h4 {
  font-size: 1em;
}