I spent some time over the holidays porting web framework sample apps over to vanilla JS.
I’ll add the same caveat here that I also included in the code:
The code works w/o polyfils in Chrome. To get it to run in a wider range of browsers you will need to add polyfills and, depending on the target browser version, compile the JS back to an older version of ES, and run a prefixer on the CSS. The wider the target set of browsers and the older the versions you are targeting the more processing you will need to do via webpack, but since the original code doesn’t need to change, those extra processing steps are out of scope for these examples.
In all cases, I tried to change as little of the original code as possible, keeping the same CSS if possible, and the same breakdown in app struture, so the apps should look and operate identically to the original samples.