What are bitcoin Keno sites?

Could you elaborate on what bitcoin Keno sites actually are? Are they platforms that allow users to wager bitcoins in a game of Keno? If so, how do they work? Do they provide a safe and secure environment for such transactions? Also, what are the benefits of using bitcoin on these sites compared to traditional currencies? Are there any risks associated with playing Keno with bitcoins? And lastly, how popular are these bitcoin Keno sites among the cryptocurrency community? I'm curious to know more about this emerging trend in the crypto gambling space.