.backtotop {
background: none;
margin: 0;
position: fixed;
bottom: 0;
right: 0;
width: 55px;
height: 60px;
z-index: 100;
display: none;
text-decoration: none;
color: #c0c0c0;
}
.backtotop i {
font-size: 50px;
}