Bulk change conditionals to the Styles

I am wondering if this could be a useful idea… For example to be able to set conditionals in the styles tab that can change the styles based on custom states or URL parameters. What I mean is lets Use LIGHT/DARK MODE.
The developer could set a custom state or option set for light dark mode then when this “switch” is made from light to dark then the Style for the body text changes to light. this could be used to reference the page background colour, a custom state, an option set to make it a permanent change etc

Anyway I see this as a way to make UX development and changes much more simplified and changing bulk Actions that apply across an entire app. Especially not with the use light and dark modes in high demand. This type of conditional set up could be applied to any part of the app in the styles tab

Would love to hear your thoughts.