OK

src/lib/Editor.svelte

@@ -21,6 +21,7 @@
 
 	let activeTab = $state<'html' | 'css' | 'shared' | 'app'>(mode === 'item' ? 'html' : 'shared');
 	let editMode = $state<EditMode>('normal');
+	let previousItemId = $state<string | null>(null);
 
 	function getKeymapExtension(m: EditMode) {
 		switch (m) {
@@ -152,6 +153,22 @@
 		sharedEditor?.dispatch({ effects: keymapCompartment.reconfigure(ext) });
 		appEditor?.dispatch({ effects: keymapCompartment.reconfigure(ext) });
 	});
+
+	$effect(() => {
+		if (mode === 'item' && item && item.id !== previousItemId) {
+			previousItemId = item.id;
+			if (htmlEditor) {
+				htmlEditor.dispatch({
+					changes: { from: 0, to: htmlEditor.state.doc.length, insert: item.html }
+				});
+			}
+			if (cssEditor) {
+				cssEditor.dispatch({
+					changes: { from: 0, to: cssEditor.state.doc.length, insert: item.css }
+				});
+			}
+		}
+	});
 </script>
 
 <div class="panel">