Isn't there a dedicated file or section where I can tell the design how to behave on mobile devices? Or does it all depend on the style.css?
I don't want to use an unedited theme, that's basically why I edited mine. But I guess the problems on mobile devices would not appear.
E.g. there seems to be a margin to the left which fits for desktop screens but not for smartphones. Maybe someone can tell me at what tags I should take a look on?