The popularity of CSS-in-JS has mostly come from the React community, and indeed many CSS-in-JS libraries are React-specific. However, Emotion, the most popular library in terms of npm downloads, is framework agnostic.
Using the shadow DOM is common when creating custom elements, but there’s no requirement to do so. Not all use cases require that level of encapsulation. While it’s also possible to style custom elements with CSS in a regular stylesheet, we’re going to look at using … Read article “Web Standards Meet User-Land: Using CSS-in-JS to Style Custom Elements”