ENH: Improve Excel header formatting with CSS-like font weight support- Added support for CSS-like font-weight properties in Excel exports- Enhanced font weight conversion for both xlsxwriter and openpyxl- Improved style inheritance and merging- Added support for header_bold parameter in Excel export- Maintained backward compatibility with existing code

Author: antznette1

pandas/io/formats/style.py

@@ -609,7 +609,7 @@ def to_excel(
             merge_cells=merge_cells,
             inf_rep=inf_rep,
         )
-        formatter.write(
+        formatter.to_excel(
             excel_writer,
             sheet_name=sheet_name,
             startrow=startrow,