Text-Wrapping without flexbox?

This is a major work in progress, so please, spare me the obvious, haha. Here is a link to my current, mostly pre-formatted Documentation page: https://codepen.io/jsharick7/pen/QWjqLrw?editors=1100

Doing a scan of the sample codePen CSS for the Documentation Challenge, I don’t see them applying any flex-box properties to get the text to wrap when I make the viewport smaller. I’m trying to figure out how they did that without the use of flex-box. I notice their “code” selector contains some text-wrap properties, but I want to wrap the articles (namely, the <p> tags.)

*The irony of using Docs on flex-box while trying to avoid flex-box is evident to me

Another issue I’m having (unrelated, but still weird), is that when I do apply any changes to the font-size in the “code” selector, for reasons I can’t wrap my head around, it changes the size of all of my <img> tags.

Any help appreciated!

Challenge: Build a Technical Documentation Page

Link to the challenge: