Brazilian Portuguese? Really ?
So, you want to learn Portuguese and the sites teaches you the brazilian version of it, alongside it's flag. By the same logic, why not teach Australian English, Mexican Spanish or even Canadian French. I really think that if you're teaching a Language, you should teach the original version of it. Brazilian Portuguese has many differences from the Original Portuguese, differences that could complicate things for a non-native portuguese speaker.
Yes, but what is the original Portuguese? Portuguese Portuguese is influenced by Brazilian Portuguese. Portuguese Portuguese itself has a lot of dialects. I think it makes sense to teach the Portuguese variant with the most speakers because that one is probably the most useful, so Brazilian Portuguese seems the right choice.
Besides the importance of Brazil in the world economy, Brazilian Portuguese sounds clearer and is easier to pick up for beginners.
I'm brazilian and I lived for the last year in Porto - Portugal. Most of the folk I met there trying to learn portuguese said that the brazilian portuguese is easier to start since it sounds clearer and opened.