CSS Vertical/Horizontal Center Alignment

/* WORKS WITH ALL MODERN BROWSERS BUT IE10 */

.inner {
    position: absolute;
    top: 50%;
    left: 50%;
    -webkit-transform: translateX(-50%) translateY(-50%);
    -moz-transform: translateX(-50%) translateY(-50%);
    -ms-transform: translateX(-50%) translateY(-50%);
    -o-transform: translateX(-50%) translateY(-50%);
    transform: translateX(-50%) translateY(-50%);
}