#return-to-top {
  z-index: 999;
  position: fixed;
  bottom: 20px;
  right: 25px;
  background: rgb(0, 0, 0);
  background: rgba(0, 0, 0, 0.7);
  width: 50px;
  height: 50px;
  display: block;
  text-decoration: none;
  -webkit-border-radius: 35px;
  -moz-border-radius: 35px;
  border-radius: 35px;
  display: none;
  -webkit-transition: all 0.3s linear;
  -moz-transition: all 0.3s ease;
  -ms-transition: all 0.3s ease;
  -o-transition: all 0.3s ease;
  transition: all 0.3s ease;
}
#return-to-top i {
  color: #fff;
  margin: 0;
  position: relative;
  left: 16px;
  top: 13px;
  font-size: 19px;
  -webkit-transition: all 0.3s ease;
  -moz-transition: all 0.3s ease;
  -ms-transition: all 0.3s ease;
  -o-transition: all 0.3s ease;
  transition: all 0.3s ease;
}

@media only screen and (min-width: 768px) {
  #return-to-top {
    right: 30px;
  }
}

#return-to-top:hover {
  background: rgba(0, 0, 0, 0.9);
}
#return-to-top:hover i {
  color: #fff;
  top: 5px;
}