This reminds me of a css switcher project I found on GitHub [1] while I was messing around with classless style sheets.
Makes it just so easy to switch and select. Embed in your html page, select an item from the drop down and see what it does to the page, when you’re happy, remove ! Simple. Genius. Wonder why I never thought of it.
Also has a demo page [2] to try it out
[1]: https://github.com/dohliam/dropin-minimal-css
[2]: https://dohliam.github.io/dropin-minimal-css/