#topBtn {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 30px;
    z-index: 99;
    border: none; 
    outline: none; 
    background-color: #000;
    color: white;
    cursor: pointer;
    padding: 15px; 
    border-radius: 10px; 
    font-size: 18px;
}

#topBtn:hover {
    background-color: #555;
}