How can I detect if iOS & Android are in Powersave mode and add a CSS class to the body?

Question

Background videos do not work on mobile devices with Powersaving mode active.

I want to detect when the page is running on a device with Powersaving active and add a Body Class so I can hide doing what I want via CSS. How can we not hide this PLAY button.

Play button disturbing the content when in Powersaving mode