.d-flex justify-content-center {
    position: relative;
    height: 290px;
    width: 290px;
    margin: 50px 20px;
    float: left;
  }
  
  .d-flex justify-content-center img {
    position: absolute;
    left: 0;
    transition: opacity 0.2s ease-in-out;
  }
  
  .d-flex justify-content-center img.top:hover {
    opacity: 0;
  }