This may get you into a solid B1 or even B2 level, but to go beyond everyday language and reach true professional proficiency and an understanding of language r

This may get you into a solid B1 or even B2 level, but to go beyond everyday language and reach true professional proficiency and an understanding of language registers and nuance, I would say a dictionary of the language in the language is an important step along the way. I recommend the Düden - Deutsch als Fremdsprache