After adding the header, the content in the popup shifts down by the height of the header. As a result, when hovering over a top site circle and if the circle is sufficiently large, then the top site detail overlaps with the circle. Visually, this looks like a flaw and also there's some flickering that can occur if you hover on the overlapping part between the circle and detail.
After adding the header, the content in the popup shifts down by the height of the header. As a result, when hovering over a top site circle and if the circle is sufficiently large, then the top site detail overlaps with the circle. Visually, this looks like a flaw and also there's some flickering that can occur if you hover on the overlapping part between the circle and detail.