#myBtn {
    display: none;  
    position: fixed; 
    bottom: 2px;  
    right: 15px;  
    z-index: 99;  
    border: none;  
    outline: none;  
    background-color: rgb(114, 114, 114);  
    color: white;  
    cursor: pointer;  
    padding: 10px;  
    border-radius:50px;  
    font-size: 18px; 
  }
  
  #myBtn:hover {
    background-color: #f75563; 
  }


  @media screen and (max-width:500px) {
    #myBtn {
      bottom: 2px;  
      right: 20px;  
      z-index: 99;  
      padding: 5px;  
      border-radius:50px;
      border: none;  
      font-size: 12px; 
    }
  }