diff --git a/.jules/bolt.md b/.jules/bolt.md
new file mode 100644
index 0000000..7c29280
--- /dev/null
+++ b/.jules/bolt.md
@@ -0,0 +1,3 @@
+## 2024-07-08 - Use DocumentFragment to batch DOM inserts
+ **Learning:** Batching DOM insertions using DocumentFragment reduces repaints and layout recalculations. While the exact performance impact relies on environment details (e.g. vitest+jsdom drops time by ~25%), it's a standard and safe optimization for large loops.
+ **Action:** Apply DocumentFragment before loops that append many elements to a live DOM container.
diff --git a/src/main.ts b/src/main.ts
index 3dfe422..08ad719 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -97,6 +97,7 @@ function reorderDoc(srcId: string, targetId: string): void {
 function renderDocList(): void {
   const list = $("#doc-list");
   list.replaceChildren();
+  const frag = document.createDocumentFragment();
   for (const doc of data.docs) {
     const el = document.createElement("div");
     el.className = "doc-item" + (doc.id === data.activeId ? " active" : "") + (doc.pinned ? " pinned" : "");
@@ -191,8 +192,9 @@ function renderDocList(): void {
       saveAppData(data);
     });
     el.appendChild(del);
-    list.appendChild(el);
+    frag.appendChild(el);
   }
+  list.appendChild(frag);
 }
 
 function switchDoc(id: string): void {