Bugzilla

I'm adding this issue to the `devtools-webcompat-team` metabug because I just ran int this [while diagnosing a WebCompat issue](https://github.com/webcompat/web-bugs/issues/89354#issuecomment-942411389), where an app added CSS rules to an empty inline style tag with `insertRule`, and I wanted to inspect other rules in context of the whole stylesheet.

Even though I'm adding this to the metabug, this has a super low priority. If I recall correctly, this is the first time I've stumbled across it, and while it confused me for a bit, I don't think we'd save any significant time by having proper DevTools-support here.

I'm adding this issue to the `devtools-webcompat-team` metabug because I just ran int this [while diagnosing a WebCompat issue](https://github.com/webcompat/web-bugs/issues/89354#issuecomment-942411389), where an app added CSS rules to an empty inline style tag with `insertRule`, and I wanted to inspect other rules in context of the whole stylesheet.

Even though I'm adding this to the metabug, this has a super low priority. If I recall correctly, this is the first time I've stumbled across it, and while it confused me for a bit, I don't think we'd save any significant time by having proper DevTools-support here.

Also, thanks to :nchevobbe, who helped me figure out what's going on there.