.btn-wsp{
  position: fixed;
  width: 60px;
  height: 60px;
  line-height: 60px;
  bottom: 20px;
  left: 20px;
  background: #28a745;
  color: #FFF;
  border-radius: 50px;
  text-align: center;
  font-size: 40px;
  box-shadow: 0px 1px 10px rgb(0 0 0 / 30%);
  z-index: 100000;
  transition: all 300ms ease;
}
.btn-wsp:hover{
    background: #28a745;
}
@media only screen and (min-width:320px) and (max-width:768px){
    .btn-wsp{
        width:63px;
        height:63px;
        line-height: 66px;
	}
}