html {
    scroll-behavior: smooth;
}
#scrollToTopBtn {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 99;
    border: none;
    border-radius: 50%;
    outline: none;
    background-color: transparent;
    cursor: pointer;
    font-size: 18px;
}

#scrollToTopBtn img {
    width: 30px;
    height: 30px;
}