.topnav {
  overflow: hidden;
  position: fixed;
  top: 0;
  left: 0;
  background-image: url(../images/back-menu.png); background-repeat: repeat;
  color: #FFFFFF;
  z-index: 999;
  width: 100%;
}
.topnav a {
  float: left;
  display: block;
  color: #FFFFFF;
  text-align: center;
  padding: 14px 16px;
  padding-right: 30px;
  padding-top: 10px;
  text-decoration: none;
  font-size: 18px;
}
.topnav a:hover {
  background-color: #DBDBDB;
  color: #000000;
}
.active {
  background-color: #4CAF50;
  font-size: 18px;
  color: white;
}
.topnav .icon {
  display: none;
}

@media screen and (max-width: 600px) {
  .topnav a:not(:first-child) {display: none;}
  .topnav a.icon {
    float: right;
    display: block;
  }
}

@media screen and (max-width: 600px) {
  .topnav.responsive {position: relative;}
  .topnav.responsive .icon {
    position: absolute;
    right: 0;
    top: 0;
  }
  .topnav.responsive a {
    float: none;
    display: block;
    text-align: left;
  }
}