.bxr-button-up {
    width: 48px;
    height: 48px;
    position: fixed;
    border: none;
    box-shadow: none;
    z-index: 1999;    
    bottom: 0;
    display: none;
    opacity: 0.5;
    filter: alpha(opacity=50);
}

.bxr-button-up.right {
    right: 0;
}

.bxr-button-up.left {
    left: 0;
}

.bxr-button-up:hover {
    opacity: 1;
    filter: alpha(opacity=100);
}

.bxr-button-up > .fa {
    font-size: 28px;
    margin-left: -1px;
}