#scrolltop {
  display: inline-block;
  background-color: #390;
  width: 50px;
  height: 50px;
  text-align: center;
  border-radius: 50%;
  position: fixed;
  bottom: 30px;
  right: 30px;
  transition: background-color .3s, 
  opacity .5s, visibility .5s;
  opacity: 0;
  visibility: hidden;
  z-index: 1000;
  font-size: 2em;
  line-height: 40px;
  color: #fff;
  box-shadow: 0 2px 5px 0 rgba(0,0,0,0.5);
}
#scrolltop .fa-arrow-up::before {
	color: #fff;
}
#scrolltop:hover {
  cursor: pointer;
  background-color: #333;
}
#scrolltop:active {
  background-color: #555;
}
#scrolltop.show {
  opacity: 1;
  visibility: visible;
}