#scroll-to-top {
    position: fixed;
    bottom: 40px;
    right: 40px;
    width: 50px;
    height: 50px;
    background-color: #333;
    color: #fff;
    text-align: center;
    line-height: 50px;
    font-size: 24px;
    border-radius: 4px;
    cursor: pointer;
    display: none;
    z-index: 9999;
    transition: background-color 0.3s ease;
}
#scroll-to-top:hover {
    background-color: #555;
}