I am trying to set a background color to the header in a Vaadin 14 Grid.
But I really have no clue how it may work.

This is my code sofar:

```
grid = new Grid<Room>(); 

```

I probably have to do some

```
@CssImport(themeFor = "vaadin-grid", value = "./styles/grid-header.css")

```

and access some Shadow DOM elements within grid-header.css, but I just can't figure out how it works.

So, does anybody know, how so set the background color of the header of a grid in Vaadin 14 ?

thanks for any help!
Thorsten