I'm the blog's author. Can you advice on some CSS fixes, I'm not experiencing what you're describing on my phone (Chrome and Firefox) nor my desktop (also Chrome and Firefox). Could you also share a screenshot please.
I see you used "width: 60%" to specify the width of the article text. That's probably good for narrower screens, but on its own can have unpleasant effects on wider ones. Consider adding "max-width: 39em" to mitigate it. You may fiddle a bit with the exact value there to see what works for your website.
As to the text size, you used "font-size: 1.4em". I think that in this regard it's best to rely on the defaults and set "font-size: 100%" in "html, body" and then "font-size: 1rem" for the tag where the main text is contained.
Smaller text would be harder to read. And it's not like the text is edge-to-edge wide.
In any case, our impressions being different only prove my point about standardized styling of webpages.