Is there a way to force reader mode or force text not to be justified like that? I'm having a difficult time reading the content (on mobile at least).

On an iPad I can't read the web page at all. The insert at the upper right overlies and obscures the main body of text.

It'd also be a good starting point to be more concrete in your ambitions. What version of C is your preferred starting point, the basis for your "Better C"?

I'd also suggest the name "Dependable C" confuses readers about your objective. You don't seek reliability but a return to C's simpler roots. All the more reason to choose a recognized historical version of C as your baseline and call it something like "Essential C".