var toTopButton = document.getElementById("to-top-button"); // When the user scrolls down 200px from the top of the document, show the button window.onscroll = function () { if ( document.body.scrollTop > 250 || document.documentElement.scrollTop > 250 ) { toTopButton.classList.remove("hidden"); } else { toTopButton.classList.add("hidden"); } }; // When the user clicks on the button, scroll to the top of the document function goToTop() { window.scrollTo({ top: 0, behavior: "smooth" }); }