Answers for "smooth scroll when click on link css"

smooth scrolling when clicking an anchor link

// smooth scrolling when clicking an anchor link 
$('.nav-item a').on('click', function () {
    if (location.pathname.replace(/^//, '') === this.pathname.replace(/^//, '') && location.hostname === this.hostname) {
        let target = $(this.hash);
        target = target.length ? target : $('[name=' + this.hash.slice(1) + ']');
        if (target.length) {
            html_body.animate({
                scrollTop: target.offset().top - 0
            }, 1500);
            return false;
        }

    }
});