q-expansion-item expanded item label highlight

[mytc]

I like to know how to styling the q-expansion-item label.
When there is the expanded item, how do I change the background of the label.
Also, is there anyway to change the label font size?
As far as I know, it does not allow to use html tag in Expansion Item label.

[zaynab-raisi]

By q-item__label class, you can style it.

[mytc]

Nope, tried. Not working.
Even so, it still does not solve the expanded item label styling problem.

[hawkeye64]

Did you make the css scoped? If so, it won't work unless you use the deep selector (look at Vue docs for more info).