diff --git a/frontend/assets/js/app.js b/frontend/assets/js/app.js
index 5730baa..d2c65ff 100644
--- a/frontend/assets/js/app.js
+++ b/frontend/assets/js/app.js
@@ -49,10 +49,10 @@ document.addEventListener('DOMContentLoaded', () => {
     window.addEventListener('resize', () => { resizeCanvas(); renderNetwork(); });
 
     document.addEventListener('keydown', (e) => {
-        if (e.key === 'Delete' || e.key === 'Backspace') {
+        if (e.key === 'Delete') {
             if (!document.activeElement || document.activeElement.tagName !== 'INPUT') {
-                if (selectedNodeId) deleteSelectedNode();
-                else if (selectedShapeId) deleteSelectedShape();
+                if (selectedNodeId) deleteSelectedNode(selectedNodeId);
+                else if (selectedShapeId) deleteSelectedShape(selectedShapeId);
             }
         }
         if (e.key === 'Escape') {
@@ -204,9 +204,9 @@ async function loadNetworkData() {
         apiFetch('links'),
         apiFetch('shapes')
     ]);
-    nodes = n;
-    links = l;
-    shapes = s;
+    nodes = Array.isArray(n) ? n : [];
+    links = Array.isArray(l) ? l : [];
+    shapes = Array.isArray(s) ? s : [];
     populateNodeSelects();
     renderNodeList();
     renderShapeList();
@@ -265,7 +265,7 @@ function selectNode(id) {
                 <div><span class="text-secondary">Type:</span> ${n.node_type}</div>
                 <div><span class="text-secondary">Status:</span> ${n.status}</div>
                 <div><span class="text-secondary">Group:</span> ${n.group_name}</div>
-                <button class="btn btn-outline-danger btn-sm mt-2" onclick="deleteSelectedNode()"><i class="fas fa-trash me-1"></i>Delete</button>
+                <button class="btn btn-outline-danger btn-sm mt-2" onclick="deleteSelectedNode(${n.id})"><i class="fas fa-trash me-1"></i>Delete</button>
             </div>
         `;
     }
@@ -282,24 +282,43 @@ function selectShape(id) {
     renderNetwork();
 }
 
-async function deleteSelectedNode() {
-    if (!selectedNodeId) return;
-    if (!confirm('Delete this node and its connections?')) return;
-    const id = selectedNodeId;
+async function deleteSelectedNode(id) {
+    if (!id) return;
+    const ok = await showConfirm('Delete this node and its connections?');
+    if (!ok) return;
     selectedNodeId = null;
     await apiFetch(`nodes/${id}`, { method: 'DELETE' });
     loadNetworkData();
 }
 
-async function deleteSelectedShape() {
-    if (!selectedShapeId) return;
-    if (!confirm('Delete this shape?')) return;
-    const id = selectedShapeId;
+async function deleteSelectedShape(id) {
+    if (!id) return;
+    const ok = await showConfirm('Delete this shape?');
+    if (!ok) return;
     selectedShapeId = null;
     await apiFetch(`shapes/${id}`, { method: 'DELETE' });
     loadNetworkData();
 }
 
+function showConfirm(msg) {
+    return new Promise((resolve) => {
+        const modalEl = document.getElementById('confirmModal');
+        const modal = new bootstrap.Modal(modalEl);
+        document.getElementById('confirmMsg').textContent = msg;
+        const btn = document.getElementById('confirmBtn');
+        let resolved = false;
+        const cleanup = () => {
+            btn.removeEventListener('click', onClick);
+            modalEl.removeEventListener('hidden.bs.modal', onHidden);
+        };
+        const onClick = () => { resolved = true; cleanup(); modal.hide(); resolve(true); };
+        const onHidden = () => { if (!resolved) { cleanup(); resolve(false); } };
+        btn.addEventListener('click', onClick);
+        modalEl.addEventListener('hidden.bs.modal', onHidden);
+        modal.show();
+    });
+}
+
 async function saveNode() {
     const data = {
         label: document.getElementById('nodeLabel').value,
diff --git a/frontend/index.html b/frontend/index.html
index 54ddc20..2ee12b4 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -329,6 +329,22 @@
     </div>
 </div>
 
+<!-- ==================== CONFIRM MODAL ==================== -->
+<div class="modal fade" id="confirmModal" tabindex="-1">
+    <div class="modal-dialog modal-sm modal-dialog-centered">
+        <div class="modal-content bg-dark">
+            <div class="modal-body text-center py-4">
+                <i class="fas fa-exclamation-triangle text-warning fs-3 mb-2"></i>
+                <p id="confirmMsg" class="mb-3">Are you sure?</p>
+                <div class="d-flex justify-content-center gap-2">
+                    <button type="button" class="btn btn-sm btn-secondary" data-bs-dismiss="modal">Cancel</button>
+                    <button type="button" class="btn btn-sm btn-danger" id="confirmBtn">Delete</button>
+                </div>
+            </div>
+        </div>
+    </div>
+</div>
+
 <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.2/dist/js/bootstrap.bundle.min.js"></script>
 <script src="assets/js/app.js"></script>
 </body>