cf-tabs.css

#custom-fields-tabs ul.tabs{
    margin: 0px;
    padding: 0px;
    list-style: none;
}

#custom-fields-tabs ul.tabs li{
    background: none;
    color: #222;
    display: inline-block;
    padding: 10px 15px;
    margin-bottom: 0;
    cursor: pointer;
}

#custom-fields-tabs ul.tabs li.current{
    background: #ededed;
    color: #222;
}

#custom-fields-tabs .tab-content{
    display: none;
    background: #ededed;
    padding: 15px;
}

#custom-fields-tabs .tab-content.current{
    display: inherit;
}