You're welcome in Russian

Silence after a спасибо feels abrupt in Russian, so one of these always comes back. Пожалуйста is never wrong; не за что fits small favours between equals; обращайтесь adds a professional, glad-to-help note.

The double duty of пожалуйста confuses no one in practice: as a reply to thanks it means you're welcome, attached to a request it means please, handing something over it means here you go. Position tells them apart.