fix

app.py

@@ -51,6 +51,10 @@ def filter_and_pivot_leaderboard(selected_datasets, selected_conditions=None, se
         aggfunc='first'
     ).reset_index()
     
+    # Convert MultiIndex column headers to string format
+    if isinstance(pivot_df.columns, pd.MultiIndex):
+        pivot_df.columns = [' - '.join(col).strip() if isinstance(col, tuple) else col for col in pivot_df.columns]
+    
     # Sort by the first dataset score in descending order
     if selected_datasets and len(pivot_df) > 0 and len(pivot_df.columns) > 2:
         sort_col = pivot_df.columns[2]  # First dataset column after Model and Type