Provide 'Back to top' functionality

1 files changed, 14 insertions, 0 deletions

diff --git a/assets/js/ed.js b/assets/js/ed.js
new file mode 100644
index 0000000..dbea865
--- /dev/null
+++ b/assets/js/ed.js
@@ -0,0 +1,14 @@
+document.addEventListener('DOMContentLoaded', function () {
+  // 'Back to top' logic
+  const intersectionObserver = new IntersectionObserver(function(entries) {
+    const topBtn = document.querySelector('.top-of-site-link');
+    if (topBtn === null) return;
+
+    topBtn.dataset.visible = entries[0].boundingClientRect.y < 0;
+  });
+
+  const topAnchor = document.querySelector('#top-of-site-anchor');
+  if (topAnchor !== null) {
+    intersectionObserver.observe(topAnchor);
+  }
+});