REST Countries API with React JS & styled-components

I learned a ton from this challenge!!

The code is messy... I need to refactor it later LOL.

I also need to implement the feature to click outside to close the filter by region.

I have one question here.

How do I make the theme toggling in sync with the different routes?

Say, when the theme is dark mode first, when I click on a country it will take me to https://example.com/italy, and then I toggle the theme here to light mode.

Now, I click the back button to return home page. The home page is still in dark mode.