Use only CSS to find and replace text - without set class or ID

For reasons that take too long to explain, I need a way to do this WITHOUT PHP or javascript - just HTML/CSS.

I've got a list of features (from a PHP function) on a page which don't have any specific class or ID. I need the CSS to look for the word WIFI on the page and replace it with an icon. Same for a few other features.

A few colleagues think they have seen a way to do this, but we can't find it. The only solutions require a span and custom class.