Centering a DIV with unknown width

centering-div-unknown-width.css

.content {
    margin: 0 auto 8px;
    display: table;
    }

.content div {
    display: table-cell;
    }

<!--[if IE]>
.content {
    display: block;
    text-align: center;
    }
.content div {
    display: inline;
    zoom: 1;
}
<![endif]-->