body {
  margin: 0 auto;
  font-family: serif;
}

.topnav {
  overflow: hidden;
  background-color: #715F9C;
}

.topnav a {
  float: left;
  color: #f2f2f2;
  text-align: center;
  padding: 12px 13px;
  text-decoration: none;
  font-size: 18px;
}

.topnav a:hover {
  background-color: #ddd;
  color: black;
}

.topnav a.active {
  background-color: #2D175E;
  color: white;
}