.topnav {
overflow: hidden;
background-color: #c0c0c0;
max-width:750px;
margin-left:auto;
margin-right:auto;
font-size: 100%;
}

.topnav a {
  float: left;
  display: block;
  color: #000;
  text-align: center;
  padding: 6px 14px;
  text-decoration: none;
  font-size: 130%;
  ttext-shadow:2px 2px 2px #666;
}

.topnav a:hover {
  background-color: #ff99ff;
  color: black;
text-decoration: none;
text-shadow: 1px 1px 1px #fff;
}

.active {
  background-color: #4CAF50;
  color: #000;
}

.topnav .icon {
  display: none;
}

@media screen and (max-width: 790px) {
  .topnav a:not(:first-child) {display: none;}
  .topnav a.icon {
    float: right;
    display: block;
  }
}

@media screen and (max-width: 790px) {
  .topnav.responsive {position: relative;}
  .topnav.responsive .icon {
    position: absolute;
    right: 0;
    top: 0;
  }
  .topnav.responsive a {
    float: none;
    display: block;
    text-align: left;
  }
}