How much room is there after an offer? - what worked for you?

It is the first offer in 3 months and I do not want to mess it up. It has been weighing on me all week. The hiring manager was friendly and open. Did it backfire?

Most employers expect a short conversation. Mine did not even blink.

I thanked them and said I was excited but hoped we could talk about the pay. They came back with a bit more.