body {
  text-align: center;
  font-family: Arial, sans-serif;
  margin: 20px;
}

.topbar {
  position: fixed;
  top: 0;
  right: 0;
  left: 0;
  background: #333;
  padding: 10px;
}

.topbar a {
  color: white;
  margin: 0 10px;
  text-decoration: none;
}

button {
  font-size: 24px;
  padding: 15px;
  margin-top: 20px;
}