#scrollToTop{
position:fixed;
left:25px;
right:auto;
bottom:25px;
width:46px;
height:46px;
border:none;
border-radius:50%;
background:#111;
color:#fff;
font-size:22px;
cursor:pointer;
opacity:0;
visibility:hidden;
transform:translateY(15px);
transition:.3s;
box-shadow:0 8px 20px rgba(0,0,0,.25);
z-index:99999;
}
#scrollToTop:hover{background:#333;}
#scrollToTop.show{
opacity:1;
visibility:visible;
transform:translateY(0);
}
@media(max-width:640px){
#scrollToTop{left:16px;bottom:16px;}
}