.btn-wsp{
  position:fixed;
  width:50px;
  height:50px;
  line-height: 51px;
  bottom:25px;
  right:25px;
  background:#25d366;
  color:#FFF;
  border-radius:50px;
  text-align:center;
  font-size:30px;
  z-index:100;
  animation: efecto 2s infinite;

}

@keyframes efecto{
  0%{
      box-shadow: 0 0 0 0 rgba(0, 242, 164);
  }
  100%{
      box-shadow: 0 0 0 25px rgba(0, 0, 0, 0);
  }
}