Potential bug - Headings not displayed correctly

I have styled my headings <h1>Heading example</h1> to appear small by editing the styling accordingly: h1 {font-size: 1em;}

This looks fine in the reviewer/previewer:

However, the editor ignores the styling and displays the heading in a comically large font:

Since the editor honours other styling changes (e.g. changing the font, font size, etc), shouldn’t it also display the headings appropriately, as specified in the styling section?

Cards in the preview/review process are subjected to the CSS of the card template, whereas the text in the fields in the editor is not.