Negotiation offer retracted????

I was in the process of negotiating a job offer with a company. They initially presented me with a rate of $40 per hour, and I countered with $45 per hour. However, I received a response from HR stating, “Sorry, we can’t offer a higher rate. Thank you for your time, and we wish you the best.”

This is the first time I’ve encountered a rejection like this during negotiations. What do you think about it?