#topBtn {
    display: none; /* Hidden by default */
    position: fixed; /* Fixed/sticky position */
    bottom: 20px; /* Place the button at the bottom of the page */
    right: 30px; /* Place the button 30px from the right */
    z-index: 99; /* Make sure it does not overlap */
    border: none; /* Remove borders */
    outline: none; /* Remove outline */
    background-color: #999; /* Set a background color */
    cursor: pointer; /* Add a mouse pointer on hover */
    padding: 5px; /* Some padding */
    border-radius: 10px; /* Rounded corners */
    opacity: 0.7;
}

#topBtn:hover {
    background-color: #666; /* Add a dark-grey background on hover */
    opacity: 1;
}