#back-to-top {
    position: fixed;
    bottom:5vw;
    right:1vw;
    z-index: 9999;
	height:auto;
    cursor: pointer;
    transition: opacity 0.2s ease-out;
    opacity:0;
}
#back-to-top:hover {
opacity:0;
}
#back-to-top.show {
    opacity: 1;
}

#back-to-top img {
float:left;width:100%;height:100%;
}