body {
    font-family: Arial, Helvetica, sans-serif;
    font-size: 20px;
  }
  
  #myBtn {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 30px;
    z-index: 99;
    font-size: 18px;
    border: none;
    outline: none;
    background-color: rgb(0, 0, 0);
    color: white;
    cursor: pointer;
    padding: 15px 20px;
    border-radius: 3px;
  }
  @media only screen and (max-width:750px) {
    #myBtn {
      padding: 7px 10px;
    }
  }
  @media only screen and (max-width:750px){
    #myBtn {
      right: 15px;
    }
  }