This is the first truly white-label web component set that I know of. It's intentionally not a design system, and looks pretty ugly out-of-the-box until you cus

This is the first truly white-label web component set that I know of. It's intentionally not a design system, and looks pretty ugly out-of-the-box until you customize it with your own styles. I think it's a really interesting approach, and has the possibility to be a Bootstrap-like foundational layer. I work on lit-html and LitElement, which Lion uses, and we're working on new userland theming systems (and standards too) that will make using and theming a set like this easier.