body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
}

.navbar {
  overflow: hidden;
  background-color: #333;
  display: flex;
  justify-content: center;
}

.navbar a {
  color: white;
  text-align: center;
  padding: 14px 20px;
  text-decoration: none;
  font-size: 18px;
}

.main {
  text-align: center;
  margin-top: 80px;
}

.center {
  display: block;
  margin: 0 auto;
  max-width: 100%;
  height: auto;
}