sticky-class.js

var sticky = document.getElementById('seo-top-sticky');
var stickyOffset = sticky.getBoundingClientRect().top + document.body.scrollTop;

console.log(stickyOffset);

var titleShown = false;

var onScroll = function () {
    if (stickyOffset < (window.pageYOffset || document.scrollTop) - (document.clientTop || 0)) {
        if (!titleShown) {
            console.log("on");
            $(sticky).addClass('on');
            titleShown = true;
        }
    } else {
        if (titleShown) {
            $(sticky).removeClass('on');
            titleShown = false;
        }
    }
};

window.addEventListener('scroll', function () {
    onScroll();
});