I am currently redoing a groupBox's template.
I would like the header to have rounded corner on top and "inverted" rounded corner at the bottom:

![alt text](https://i.stack.imgur.com/ClNQd.png)

I managed the above template quite easily by rounding the top corners of the content part and putting the content on top of a "background" container having the darkest color as background.

BUT...

my specifications require that the content's background (lightgray on the picture) might be transparent (i.e.: it should be possible to see right through the content part without having to loose the header's background color). And this is where I'm stuck...

I could easily split this control into two rows of a grid, one for the header, the other for the content and have pretty rounded corner at the top, but I would not be able to get those "inverted" rounded corner at the header's bottom, would I?

so I would be really glad if somebody could either:

* point me to a solution (involving whatever dirty trick)
* confirm that what I want to do is impossible

thanks in advance