The Apache eCharts project is a web-based charting library. It was started in 2013 and built using 77.5K lines of TypeScript. It is well documented and has over 200 examples of its API’s usage. The examples allow you to toggle between light/dark mode and there is a cheat sheet and a theme builder with several tasteful presents to choose from.
This is a library I hadn’t heard of before but Mark shows it off a bit.