I second Mithril as a great choice. Two things I wrote in it:

https://narrafirma.com/try-narrafirma/

https://github.com/pdfernhout/Twirlip7

Combining Mithril ( https://mithril.js.org/ ) with Tachyons ( http://tachyons.io/) or a similar CSS approach is also a great option to avoid having to write that much CSS. That way almost all your code can be in one language and easy to refactor -- especially if you use TypeScript.