#back-top {
    background: url(../icons_new14.png) 13px -1553px no-repeat #000;
    z-index: 1000;
    font-size: 0;
    height: 52px;
    position: fixed;
    right: 40px;
    top: 50%;
    width: 52px;
    cursor: pointer;
    margin: 0;
}