I'm trying to include hover-over pop-ups in my character sheet, to contain details that would otherwise clutter things up. They appear whenever a player hovers over one of the "ankh" icons: --> My CSS uses z-index to ensure the pop-ups appear on top of the other elements, which usually works: . charsheet input . sheet-hoverpopup + span + div { left : calc ( ( -10% ) / 2 ) ; bottom : 20px ; height : 190px !important ; width : 150% ; display : none ; (changed to "block" by a :hover pseudo-class elsewhere) position : absolute ; background : url (" <a href="https://imgur.com/kBl8aTO.jpg" rel="nofollow">https://imgur.com/kBl8aTO.jpg</a> "); background-size : 100% ; border : 3px white outset ; z-index : 250 ; } My problem arises when I have multiple columns of fieldset rows. Unfortunately, it seems z-index is only able to position elements within a column --- no matter how high I set the z-index, my popups refuse to cover up elements in a previous column: I've scoured the Internet, but I can't quite figure out the right search terms to pull up the answers I'm looking for. Anyone have any advice or insight on how to guarantee my popups stay above the rest of my sheet? Thanks in advance!