diff --git a/themes/intotheeast/templates/trip.html.twig b/themes/intotheeast/templates/trip.html.twig
index 7a9ceaf..231d9d7 100644
--- a/themes/intotheeast/templates/trip.html.twig
+++ b/themes/intotheeast/templates/trip.html.twig
@@ -559,8 +559,28 @@ function parseGpxFiles(urls, callback) {
});
}
})();
+
+/* ── Back to top ─────────────────────────────────────────── */
+document.addEventListener('DOMContentLoaded', function () {
+ var btn = document.getElementById('trip-totop');
+ if (!btn) return;
+ var threshold = window.innerHeight * 0.8;
+ var shown = false;
+ btn.addEventListener('click', function () {
+ window.scrollTo({ top: 0, behavior: 'smooth' });
+ });
+ window.addEventListener('scroll', function () {
+ var shouldShow = window.scrollY > threshold;
+ if (shouldShow !== shown) {
+ shown = shouldShow;
+ btn.classList.toggle('is-visible', shown);
+ }
+ }, { passive: true });
+});
+
+