// Injects a scroll-to-top button that appears after scrolling down 300px. // When clicked, it smoothly scrolls the page back to the top. window.addEventListener("scroll", function () { const btn = document.getElementById("scrollToTop"); btn.style.display = window.scrollY > 300 ? "block" : "none"; }); function scrollToTop() { window.scrollTo({ top: 0, behavior: "smooth" }); } document.addEventListener("DOMContentLoaded", () => { const btn = document.createElement("button"); btn.id = "scrollToTop"; btn.textContent = "↑ Top"; btn.setAttribute("aria-label", "Scroll to top"); btn.onclick = scrollToTop; document.body.appendChild(btn); });