.topnav {
    overflow: hidden;
    background-color: #000;
    width: 100%;
    position: absolute;
    left:0;
    top:0;
    display: none;
}

.topnav a {
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 17px;
    text-transform: uppercase;
}

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

.topnav a.icon {
    float: right;
    display: block;
}

.topnav.responsive { display: block; margin-top: 50px; }

.topnav.responsive .icon {
    position: absolute;
    right: 0;
    top: 0;
}
.topnav.responsive a {
    float: none;
    display: block;
    text-align: left;
}