iphone 12 pro black screen (won't turn on?)

Last night my phone (12 Pro 128gb) was working fine. I placed it on a wireless charger like I do most nights. This morning the screen is dark. It appears to be turned off. I tried turning it on and also to hold both buttons. the screen remains dark. When I shine a light on the screen I so not see any reflection of a screen. I believe this means it is indeed off. I tried placing it on a wired charger and even a few other chargers. Any ideas? thanks