is it possible to develop close friendships at work?

i’ve always had this social rule in my head telling me my college friends are my last round of friends bc work friends are just “work friends” and nothing more. But my friend I met through work and I have become rlly close in the span of the last 8 months. We text each other about our day and we tell each other (almost) everything and hang out all the time. I say almost bc i filter myself bc i dont want her to know all the details of my life bc after all I do work with her.