REST Countries API with color theme switcher with Nextjs & Tailwind

I suggest making the border countires in country detail page linked to other countries so user doesn't have to go back to the catalog and find it manually.

I think having the rows of countries in the catalog the same height would server better. I suggest to rework the html semantics so the catalog is an <ul> tag with each country being <li> list item.

Great work anyway!