#backToTopBtn{transition:all 0.3s ease;opacity:.9;position:fixed;z-index:999999;display:none;width:45px;height:45px}#backToTopBtn:hover{opacity:1;transform:translateY(-4px)}body:not(.single-product) #backToTopBtn{bottom:100px;right:10px;left:auto;transform:translateX(0)}body.single-product #backToTopBtn{right:5px; bottom:270px;}