Set class on html not working

Hi, I'm using BlazorStyled with MatBlazor, I could style like this fine

```

.xxx {
background: rgba(20,20,20,0.75);
}

```

But I could not get it working like this

```

xxx {
background: rgba(20,20,20,0.75);
}

```

I could get it working on body and using classname so blazorstyled is setup correctly.

The issue mentions the Styled component and MatAppBar, but no source file or test location. Start by reproducing the working class-based style and the failing Styled rule, then trace how each is applied to the HTML element. Done means the Styled rule applies to MatAppBar as expected, with a regression test if the project has applicable tests.

Written by the indexing model from the issue text.