How to align text vertical center in div with css

display: table-cell;
vertical-align: middle;


#box {
    height: 90px;
    width: 270px;
    background: #000;
    font-size: 48px;
    font-style: oblique;
    color: #FFF;
    text-align: center;
    margin-top: 20px;
    margin-left: 5px;
    display: table-cell;
    vertical-align: middle;
}
#wrapper {display:table;}
#cell {display:table-cell; vertical-align:middle;}