ul.tab {
    list-style-type: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    border: 1px solid #ccc;
    background-color: #f1f1f1;
}

ul.tab li {float: left;}

ul.tab li a {
    display: inline-block;
    color: black;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
    transition: 0.3s;
    font-size: 17px;
}

ul.tab li a:hover {background-color: #ddd;}

ul.tab li a:focus, .active {background-color: #ccc;}

.tabcontent {
    display: none;
    padding: 6px 12px;
    border: 1px solid #ccc;
    border-top: none;
}