So funny to me how you wasted time giving all this feedback but OP is just going to feed it into Claude and not actually read anything you said. Don't reward people that don't care about what they're building with effort, it makes the world a worse place.
Halfway through the book myself, lotta good techniques on how to think about visualizing data sets. Found it way more accessible than many of the more academic books.
1) None of the animations are useful. None of the scroll gates are useful. They all get in the way. Remove them. All of them.
2) Don't make a person scroll so goddamned much. It's maddening and unnecessary.
3) Have a persistent table of contents on the side if your section headers actually matter.
4) Don't ignore Web Content Accessibility Guidelines for content readability. Your tiny low contrast text hurts my eyes.
5) Don't ignore user preference for dark text on light background.