Polylang Language Switcher customization

Hi, we are trying to customize the default Polylang Language Switcher dropbox that we are using on the standard top menu configured previously with the standard customize on WordPress.

Basically, we would like to customize dropbox width, borders, and so on.

An alternative we are evaluating is to try to show languages like this: EN | ES | IT

Any link, documentation, or suggestion?

Thanks in advance.