This is beautiful and highly readable but, still, I yearn for a detailed line-by-line explainer like the backbone.js source: https://backbonejs.org/docs/backbone.html
That is really beautiful literate program. Seeing it after a long time. Here is a opus generate version of this code - https://ashish01.github.io/microgpt.html
ask a high end LLM to do it
Andrej Karpathy has a walkthrough blog post here: https://karpathy.github.io/2026/02/12/microgpt/