Devtools panel dark mode

I have a webextension I built that extends DevTools. I would like to provide a dark mode so my panel matches when the user selects DevTools > Settings > Themes > Dark. How can I get the current theme? “devtools.theme” is set in about:config but webextensions do not have access the about:config. and the event

Maybe the dark mode css media query also works these days, since this predates that.