Goshdarn I love this post. I enjoyed my morning coffee while looking at the calculations, and the description of the debugging mode. It's a clever usage of native components. Currently my experience is with SwiftUI and it's almost too easy to make your own components. However that doesn't make it the best option as you described, native components are often very full-featured. I checked your post on Firefox on iOS, which is arguably an obscure browser, and it worked fine.

Very well done.