Rest Countries API - React Router, Styled Components, some Typescript

I'm happy with the result of this app, but I feel like my code organization leaves something to be desired. This was my first time using styled-components, and I ran into the problem of treating them too much like components at first. I refactored by splitting the codebase into smaller pieces and with the smaller components it was more convenient to keep the styles in the same file, but the larger layout components got unwieldy so I made seperate style files. Any suggested repos or reading that might be helpful in this regard?