.back {margin: 15px;
    cursor:pointer;
    border-radius:50%;
    background-color: black;
    color:white;
    padding: 5px;
         
  }

  body, html {
    background-color: #B9F734;
    height: 100%;
    margin: 0;
  }


  .bg {
    height: 100%; 
    background-position: center;
    background-image: url("animaux.jpg");
    background-repeat: no-repeat;
    background-size: contain;
  }