Responseive countries webapp using API with theme switcher (ReactJS)

My first advanced challenge. I took a fair bit of time completing this since... I kind of got bored. I had it all done and working weeks ago, but the CSS was painful at times - I even restarted my stylesheet completely over from scratch. Maybe I ought to invest in a pro subscription already.

If I were to redo this I would probably start by using React Router from the beginning - by the time I thought to implement it I had already finished.

My question is that why are some of the design screenshots for the dark and light themes different in terms of margins and whatnot?