Ehm, in the first link I read that for the 3 :focus examples is needed "(JS help for Safari/Chrome)",
and for the 3 :target examples is needed "(JS help for IE)" (the :target is only IE9+). :rolleyes:
I don't know if it can fit into your system/model, but out of my hobby room came two scriptless alternatives.
Both are tested in Firefox, Chrome, Opera, Safari-Win and IE7 and IE10; I assume the IE's between will do it too.
A pure css popup solution
A pure html popup solution