How to make the contents of a round-cornered border be also round-cornered?

Question

I have a border element with rounded corners containing a 3x3 grid. The corners of the grid are sticking out of the border. How can I fix that? I tried using ClipToBounds bu

Answer 1

Make the grid smaller or the border larger. So that the border element completely contains the grid.

Alternatively see if you can make the grid's background transparent, so that the "sticking out" isn't noticeable.

Update: Oops, didn't notice this was a WPF question. I'm not familiar with that. This was general HTML/CSS advice. Maybe it helps...