D2R difficulties vs D2 original

In D2 original you can choose Normal/Nightmare/Hell difficulties when start game.
Is the same in D2R, after we will finish the game(online), we will progress to Nighmare? Cause now nowere is written that Noraml difficulty is the current one… have the difficulties been merge into single one?

It’s still that same as original. Once you complete normal, you go to nightmare. Once you finish that you go to hell.

You can check your difficulty by entering the chat lobby and hosting a game there.