For ease of maintenance and portability I think markdown is really the king of formats for blog content. Are you writing the posts in HTML? Why are you intermittently using <span> for paragraphs and to wrap other elements?
Regarding the use of <span> is because the <p> tag with the chosen CSS leaves too much space after <h*> tags, while <span> doesn't, and as I wanted to just use HTML tags and not create my own version of the CSS, I found <span> the easiest way to achieve that.
That's the reason I pointed out the <span> usage - your source of truth for your data is HTML, but in this case it's already getting mixed up with design-related oddities.
Not bashing your choice for your blog, I think it's reasonable. I just wonder if HTML is the most resilient way to store blog data. It's something I considered a lot when redoing my blog last year.