#topBtn {
    display: block;
    position: fixed;
    top: 50%;
    right: 5px;
    width: 2em;
    height: 2em;
    background-color: rgba(0, 197, 255, 0.5);
    border-radius: 50%;
    font-size: 30px;
    text-align: center;
    line-height: 2em;
    color: black;
}