I've been messing with the CSS on a test application for a while but can't quite seem to figure out how to update the color just for the header div portion of the calcite popover. I see that there is a css variable for --calcite-popover-background-color, but that updates the complete popover and not just the header section.
In my searching I also came across the concept of configuring a custom theme, which sounds good, but I could not find any property there either to do exactly what I want. I also tried using custom css for the header class of the popover, but it also appears to do nothing. Does anyone know what CSS can be used to update the parts of a calcite popover like just the header background, border, and close button?
Here is a simple codepen https://codepen.io/windowslover/pen/KwVWBWW?editors=1100 that I have been working on in my testing. Any help is appreciated! Thanks.