Update app.py

app.py

@@ -137,10 +137,12 @@ def demo():
         vector_db = gr.State()
         qa_chain = gr.State()
 
+        # Inject custom CSS to limit left column width
         gr.HTML("""
         <style>
-          .gr-block.gr-box:nth-child(1) {
-            max-width: 180px;
+          .gr-block.gr-box { display: flex; }
+          .gr-block.gr-box > div:first-child {
+            max-width: 180px !important;
             flex: 0 0 180px !important;
           }
         </style>