Using gendered words like "bro" and "girl" as gender-neutral terms of address

These words fascinate me, because all of them can be used both specifically as masculine/feminine but also as general terms of address to someone of any gender, but not always in the same contexts. Like, a guy calling a girl bro seems more common than dude, but it still happens. On the other hand, I've been called girl plenty of times as a dude usually when I'm the only guy with a bunch of girls, but it still crosses the gender line there. Like, both words primarily cross lines when the person being crossed to is the minority, but the ability to even cross over is interesting to me.