.back-to-top {
    position: fixed;
    right: 40px;
    bottom: 100px;
    cursor: pointer;
    opacity: 1;
    z-index: 9;
    -webkit-transition: all .3s ease 0s;
    -moz-transition: all .3s ease 0s;
    -ms-transition: all .3s ease 0s;
    -o-transition: all .3s ease 0s;
    transition: all .3s ease 0s;
    z-index: 99999999;
}

.back-to-top.transparent {
    opacity: 0;
    /* IE8 */
    filter: alpha(opacity=0);
    pointer-events: none;
}

.back-to-top img {
    width: 100%;
    height: 100%;
}

@media only screen and (max-width: 961px) {
    .back-to-top {
        right: 10px;
    }
}