diff --git a/app/page.tsx b/app/page.tsx
index d91aa6c..1c8cab1 100644
--- a/app/page.tsx
+++ b/app/page.tsx
@@ -38,9 +38,7 @@ export default function Home() {
 
         {/* Main content */}
         <main className="container mx-auto px-3 sm:px-4 py-6 sm:py-8">
-          <div className="max-w-6xl mx-auto">
-            <AudioEditor />
-          </div>
+          <AudioEditor />
         </main>
 
         {/* Footer */}
diff --git a/lib/audio/buffer-utils.ts b/lib/audio/buffer-utils.ts
index 62fdc2d..cfa7919 100644
--- a/lib/audio/buffer-utils.ts
+++ b/lib/audio/buffer-utils.ts
@@ -112,7 +112,7 @@ export function insertBufferSegment(
 
     // Copy after insert point
     for (let i = insertSample; i < buffer.length; i++) {
-      targetData[insertBuffer.length + i] = sourceData[i];
+      targetData[insertSample + insertBuffer.length + (i - insertSample)] = sourceData[i];
     }
   }