This is where you can share your code for solving the Dark Mode Toggle exercise 
Okay so the flash of unstyled content is the real enemy here. I’ve seen that script-in-head trick work wonders for killing the flicker.
It’s all about getting that data-theme attribute on the documentElement before the browser even thinks about rendering.
The incentive structure of the browser rendering pipeline is what creates this problem. You’re essentially racing the parser.
