How do I make a style apply to all the websites.

Ginfio

I want the styles to apply to all the websites on chrome, so how do I do that?
As of right now, I don't have any specific websites to apply to, and it isn't working.

Merrick919

https://mybrowseraddon.com/dark-mode.html
This extension basically inverts all colours so some colours may be weird, but it kinda works.