little menu bug

[Error]

This issue is reproducible in Chrome 47.0 and Firefox 42.0, and also causes the dropdown menus to occasionally disappear under other content as well (such as the user profile page infobox). The fix is adding a positive and non-zero z-index to the .popup_menu class, such as the one below.

Code:

.popup_menu { z-index: 9999; }

I'd suggest using a relatively large z-index here, as there is no meaningful use case (that I know of) where you'd want the dropdown menu to disappear below any other element on the page when the user opens it.