edit style in main.html to this
.topnav input{
float: left;
color: #f2f2f2;
text-align: center;
padding: 14px 16px;
text-decoration: none;
font-size: 17px;
background-color: #333;
border: none;
-moz-user-select: -moz-none;
-khtml-user-select: none;
-webkit-user-select: none;
-o-user-select: none;
user-select: none;
}
.topnav input:hover {
background-color: #ddd;
color: black;
-moz-user-select: -moz-none;
-khtml-user-select: none;
-webkit-user-select: none;
-o-user-select: none;
user-select: none;
}
.topnav input.active {
background-color: #04AA6D;
color: white;
-moz-user-select: -moz-none;
-khtml-user-select: none;
-webkit-user-select: none;
-o-user-select: none;
user-select: none;
}
To disable the selection of button on top bar