In college, we had two bars that still had smoking despite it being banned in our state. The exception was it had to have doors and a completely separate HVAC. One bar had a smoking second story that had most of the pool tables and TVs while downstairs was a more relaxed area. Another bar bought out the building directly behind them and put a door connecting the two buildings.

Hookah bars got wrapped up in the smoking ban too which I think was an overreach. You go to a hookah bar to smoke, you don't go there to watch a game, shoot pool, and have a beer. The one hookah bar in town actually sued the state over it. Because they also sold hookah supplies, they were exempted.

The hookah supply loophole is interesting. I guess that would also explain cigar lounges as these are cigar shops as well. Vegas still also allows it I believe at least in some casinos. Vegas airport had smoking sections last time I connected through there too.