a#gantry-totop {
    background: rgba(0, 0, 0, 0) url("../images/scroll-to-top.png") no-repeat scroll right top;
    display: block;
    font-size: 1px;
    height: 51px;
    line-height: 1px;
    text-indent: -9999em;
    width: 51px;
    z-index: 999;
}