https://wikischool.org/explore
https://wikischool.org/explore/Ludwig%20Wittgenstein?l=en&t=... (read an article chronologically)
The larger goal is to make self-study more effective and enjoyable. Desktop browser recommended for now, as the mobile UX needs improvement.
The text actually fills the screen rather than just hiding in the gutter on the left, and even though you've removed most styling cues around links and actions, it's done in a way that it's still obvious what everything does, so the main content can be clearer.
The dynamic sidebar table of contents is also particularly effective - on desktop, everybody has a widescreen monitor now and it's disappointing now few sites take advantage of it.
My only two critical points are your choice of typeface, which is awful and significantly degrades the experience (browsing with fonts turned off is a great improvement), and the speed - not only does clicking a link take several seconds to do something but there isn't really any indication whether things are happening or not.
The speed issue is really a Wikipedia (and Archive.org) API fetching issue plus some parsing time. I am planning to make the data fetching parallel, but need to do some data-source-code refactoring first. A better loading indication UI will also help.
A bug to report: inspired by comments elsewhere in this thread, I searched for "radiation", and your interface is rendering the bulleted list about different kinds of radiation above the actual first paragraph (which ends with "This includes:" to introduce the list).