In a Pandoc Markdown document, I would assume
# My Heading {custom-style='style1'}
Some text ...
# Second Heading {custom-style='style2}
to result in the heading "My Heading" having the "style1" and "Second Heading" to have "style2" in DOCX (Word) output.
However, both headings in the DOCX output file simply have the style "Heading 1".
How can I correctly assign "My Heading" to have the "style1"?