16px padding in the header instead of 24px

[jasperjansz]

Currently, the padding for the body and the header of the popup are both 24px.

By having the padding for the header be smaller, 16px, we establish a clearer hierarchy of content. It makes it clear the header is not part of the body and looks better:

Here's a breakdown:

Another:

I know it's easier to have the same padding all around, but in this case, this change makes our UI clearer and more scannable. The same goes for mobile.