.topnav {
  margin: 0 auto;
  overflow: hidden;
  position: relative;
  max-width: 1078px;
  display: block;
  font-size: 120%;    
}
.topnav a {
  float: left;
  display: block;
  color: #333;
  text-align: center;
  padding: 16px 20px;
  text-decoration: none;
  transition: background .25s ease-in-out;
  -moz-transition: background .25s ease-in-out;
  -webkit-transition: background .25s ease-in-out;
}
.topnav a:hover {
  background-color: #eee;
  color: black;
}
.topnav .icon {
  display: none;
} 
@media screen and (max-width: 630px) {
  .topnav a:not(:first-child) {display: none;}
  .topnav a.icon {
    float: right;
    display: block;
  }
}
@media screen and (max-width: 630px) {
  .topnav.responsive {position: relative;}
  .topnav.responsive a.icon {
    position: absolute;
    right: 0;
    top: 0;
  }
  .topnav.responsive a {
    float: none;
    display: block;
    text-align: left;
  }
}