Corners of popup are missing

[kaldari]

The corners of the popups are missing (see screenshot)...

This is in Chrome on MacOS. I assume you're trying to do rounded corners which aren't working well for some reason. I would suggest just removing the rounded corners (which would better match PagePreviews on Wikipedia). It would also be nice if the pop-ups had a drop shadow so they were more visually distinct from the page.

[Krinkle]

I've noticed the same in Firefox on macOS.