How to hide list of matches if there are no children?

[stefanwatt]

Trying to have the result list and the prompt in a separated layout like this:

It works fine as long as there's some results to display but looks stupid when i first open anyrun:

As you can see the empty result list with it's border is still displayed below the prompt.

I tried using pseudoclasses to hide list#main like so:

list#main:empty {
  border: none;
  background-color: rgba(0, 0, 0, 0);
}

but without success. Seems like when I use an unsupported keyword the app goes back to it's default styling.

Would be nice to have a way to conditionally hide the list.