.screentable ul{
    list-style: none;
    padding: 0;
    margin: 0;
}
.nav>li{
    float: left;
    font-size: 16px;
}
.screentable ul a{
    display: block;
    text-decoration: none;
    /*width: 150px;
    height: 30px;*/
    text-align: center;
    line-height: 30px;
    color: white;
    /*background-color: #3B3B3B;*/
    font-size: 14px;
}
.drop-down{
    position: relative;
}
.drop-down a{
    text-align: center;
}
.drop-down-content{
    padding: 30px;
    display: none;
    position: absolute;
    top:30px;
}
.drop-down-content li:hover a{
    background-color: rgb(194, 36, 36);
}
.nav .drop-down:hover .drop-down-content{
    display: table-column;
}