.udNavbar {
    overflow: hidden;
    background-color: #333;
    position: fixed;
    top: 0;
    width: 100%;
}
  
.udNavbar a {
    float: left;
    display: block;
    color: #f2f2f2;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    font-size: 17px;
}
.udNavbar a:hover {
    background: #ddd;
    color: black;
}