Blog category page showing bold text

Hi,

I've got an odd problem on this category page:

https://commonside.net/blog/

All of the text is showing as bold, although if I inspect in the browser, there don't seem to be any inherited styles and the para is inheriting the body text styles. But it looks like some inheritance is going on as the bold text extends right down to the copyright info at the bottom of the page. I also thought it might be an unclosed tag but the HTML validates.

I've already:

- validated HTML and CSS (a few errors, but these are sitewide)
- purged the cache
- deactivated plugins installed since the problem began
- checked for inheritance problems in my CSS

Thanks for the help,

Giselle