Update app.py

app.py

@@ -140,7 +140,7 @@ def download_file_from_url(url, output_dir, filename):
 def download_book_cover(book_id, output_dir):
   """Download book cover from Google Books API using Book ID."""
   try:
-      image_url = f"http://books.google.com/books/content?id={book_id}&printsec=frontcover&img=1&zoom=1&edge=curl&source=gbs_api"
+      image_url = f"https://books.google.com/books/publisher/content/images/frontcover/{book_id}"
       
       response = requests.get(image_url, timeout=30)
       response.raise_for_status()