CSS Only Theme Switcher

This is a website theme switcher made using CSS only*. Click the moon above to try it out! You can also reach it by using your keyboard (Tab to focus, and Space to activate).

Unlimited themes-version

* The solution uses a tiny bit of optional JavaScript to store an item in localStorage, which allows the browser to remember which theme was selected when reloading the page.

I wrote an article on my website explaining the functionality behind this.