Actually, the styling applies to the class regardless of the HTML element. And the chosen element may have some default styling already applied, e.g.,…
And again, this is considered bad form, and though I’m not a purist about it, I’d agree this is not a good direction to go in. In this case, I’d suggest just making an HTML document – which you can natively create and edit in DEVONthink – and writing raw HTML markup as that’s what’s already going on here. @signsinthedust is saving nothing by putting it in a Markdown document.