#btn-fixed-whatsapp {
  position: fixed;
  bottom: 20px;
  left: 20px;
  display: block;
}

@media (min-width: 300px) {
  .icon-whatsapp {
    width: 40px;
    height: 40px;
    transform: scale(1.1);
    transition: 0.2s linear;
  }
}

.icon-whatsapp {
  width: 50px;
  height: 50px;
  transform: scale(1.0);
  transition: 0.2s linear;
}