I am seeing css styles in javascript more and more now. Is this a performance thing?

Worth noting that the same author created a fairly popular library for JS styles: https://github.com/casesandberg/reactcss

It's more about getting locally-scoped, composable CSS than performance. It's similar in concept to CSS Modules.

I believe it's more of a convenience, and React-based projects are setup for it. You can avoid dealing with the global cascade and there's no need to maintain a parallel set of files for styling; it's all in the JavaScript.

Glitch in chrome: https://share.viewedit.com/hpHseCYcRVRFowSoxWEV2H

Glitchy in Firefox 47, Ubuntu 15.10

https://snag.gy/1ELC2A.jpg

Along the same lines, did you get permission from Henry to use his name?

It's like 95% similar to the builtin mac picker. (ctrl+command+space)