@media (max-width: 768px) {
  .whatsapp {
    bottom: 50px;
    right: 25px;
    width: 50px;
    height: 50px;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .whatsapp {
    bottom: 50px;
    right: 25px;
    width: 60px;
    height: 60px;
  }
}