.back-to-top {
  position: fixed;
  bottom: 20px;
  right: 20px;
  display: none;
  font-size: 24px;
  color: #fff;
  background: #000;
  padding: 5px 10px;
  border-radius: 5px;
  cursor: pointer;
  z-index: 1000;
}
 
.back-to-top:hover {
  background: #333;
  text-decoration: none;
}