feat: add button scroll to top

Views/Home/Index.cshtml

@@ -672,6 +672,14 @@
     </div>
 </section>
 
+<!-- Scroll to top FAB -->
+<div class="fixed right-4 bottom-6 md:right-10 md:bottom-10 z-50">
+    <button type="button" id="scrollTopFab"
+        class="btn btn-success btn-circle text-white shadow-xl hidden" aria-label="Kembali ke atas">
+        <i class="ph ph-arrow-up text-xl"></i>
+    </button>
+</div>
+
 @section Styles {
     <link rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.css" />
 }
@@ -863,7 +871,7 @@
             rootMargin: '0px 0px -50px 0px'
         };
 
-        const observer = new IntersectionObserver(function(entries) {
+        const observer = new IntersectionObserver(function (entries) {
             entries.forEach(entry => {
                 if (entry.isIntersecting) {
                     entry.target.classList.add('animate-fade-in');
@@ -896,5 +904,25 @@
                 });
             });
         })();
+
+        // Scroll-to-top floating action button
+        (function () {
+            const scrollFab = document.getElementById('scrollTopFab');
+            if (!scrollFab) return;
+
+            const toggleVisibility = () => {
+                scrollFab.classList.toggle('hidden', window.scrollY < 300);
+            };
+
+            toggleVisibility();
+            window.addEventListener('scroll', toggleVisibility);
+
+            scrollFab.addEventListener('click', () => {
+                window.scrollTo({
+                    top: 0,
+                    behavior: 'smooth'
+                });
+            });
+        })();
     </script>
-}
+}