html {
    scroll-behavior: smooth;
}

.scrollToTopBtn {
    cursor: pointer;
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 100;
    opacity: 0;
    transform: translateY(100px);
    transition: all .5s ease;
}

.showBtn {
    opacity: 1;
    transform: translateY(0)
}