I got a library for you, also a really nice course of establishing mental models, and a gentle introduction to web components for you. Happy weekend!
Dinero.js lets you express monetary values in JavaScript. You can perform mutations, conversions, comparisons, format them extensively, and overall make money manipulation in your application easier and safer.
Just JavaScript is Dan Abramov’s distilled mental model of how JavaScript works and a collaboration with Maggie Appleton. It’s a great course for anyone who’s looking to strengthen their foundations of JavaScript. Highly recommended
This article goes through what web components are, how we can build them without a framework, and some limitations to keep in mind during development. It is a nice, gentle introduction for anyone looking to get started.