React.js single-page app

Hello everyone! This is my second exercise with React.js. This challenge gave me the opportunity to use and practice for the first time with the react-router-dom and therefore with the single-page-applications.

Any advice and feedback is welcome!

Unfortunately in the deployment I am encountering a problem that was not there during the development: in smartphone mode the select-container covers the first card of the countries.

Another problem I encountered is the fact that, in the route dedicated to country-details, if I change country by clicking on the borders button, when I click on the back button of the browser I cannot go back in the browser-history: the url changes correctly, but the UI does not change.

Thanks so much!