styled-components is what got me to switch from LESS to css-in-js, and I'm so grateful. Anyone interested learning about css-in-js for the first time would benefit from understanding the styled-components model, but there's already churn in that category, and new libraries inspired by styled-components that take it further. Here's an interesting perspective on the history of CSS-in-JS:

https://github.com/streamich/freestyler/blob/master/docs/en/...

Currently i'm working with Emotion (https://github.com/emotion-js/emotion) and enjoying it