.whatsapp-float {
  position: fixed;
  right: 20px;
  bottom: 20px;
  z-index: 99999;
  display: block;
}

  .whatsapp-float img {
    display: block;
    max-width: 180px;
    height: auto;
  }

@media (max-width: 480px) {
  .whatsapp-float {
    right: 15px;
    bottom: 15px;
  }

    .whatsapp-float img {
      max-width: 150px;
    }
}