ZTE Warp Elite screen gone black; phone is on, but cannot turn it off

[beneficii]

I was putting my phone in a carrying case designed for it, and the screen went black. I tried pressing the power button and nothing happened. I checked and the blue LED light was on. I thought maybe the case prevented me from pressing all the way down, so I took it back out and tried it again, but to no avail. I've tried holding down the power button, pressing volume up + volume down + power, none of that does anything. The screen is black, but the phone appears to be on as indicated by the blue LED light being on.

What the heck? What can I do?

 

[woodgaser]

press and hold power button for about 15 seconds it will re-boot then