body {
  font-family: Arial, sans-serif;
  text-align: center;
  background: #f7f7f7;
}

button {
  margin: 10px;
  padding: 10px 20px;
  font-size: 18px;
  cursor: pointer;
}

.section {
  display: none;
}

#menu h1 {
  font-size: 32px;
  margin-top: 50px;
}