Update column layout for export options in app.py: adjust button column widths to improve UI spacing and enhance user experience when downloading portfolios.

app.py

@@ -1201,7 +1201,7 @@ with tab2:
                         st.session_state['export_file'][col] = st.session_state['export_file'][col].map(st.session_state['export_dict'])
             
             if 'export_file' in st.session_state:
-                download_port, merge_port, partial_col, clear_export, blank_export_col = st.columns([1, 1, 1, 8])
+                download_port, merge_port, partial_col, clear_export, blank_export_col = st.columns([1, 1, 1, 1, 8])
                 with download_port:
                     st.download_button(label="Download Portfolio", data=st.session_state['export_file'].to_csv(index=False), file_name="portfolio.csv", mime="text/csv")
                 with merge_port: