Open Panel to gray out caller page content

Open Panel to gray out caller page content

Hi,

I'm not sure if I am using the correct terms for the question I am asking.

In page content, I click a button/link to open a Panel it can be in any data-display value. When the panel appear, I would like to caller page content to be gray out or technically cover it with gray overlay.

How I can do that? Is there any existing built-in attribute I can set or I will need to do this with my own js/jquery?

Hope my explanation is clear enough.

Thanks.