Device-Level Time Limits and Access in Screen Time?

Is there a way to set a usage limit at the device level? I want to limit the total number of hours my child spends on her device each day. I don’t care what apps/categories she’s using.

Also, is there a way to pause a child’s device? I can do this on my router and through my cell service but have to go to each individually. It would be nice to do it in one place, ideally in Screen Time.