I trimmed down the code for y’all. Here is the most minimal parts of it. How can I make this work in Opera? (yes, and maybe even IE). By work in Opera I mean render like it does in Webkit and Gecko, like so:

Apparently the magic that allows this to work is the css height: 0; declaration. I’m not sure why that is, but it gives me the chills (and probably nightmares entitled Box Model).

Or, if it’s easier, you can download a html file (css embedded).

Knowing that my task would be easier if I had the words I went on a quest to find the name for setting a superscript directly a above a subscript . The closest I came was Mixed Tensor, which is, like, a math thing.
I’ve searched typographic sites, and linguistic sites, a reverse dictionary.

And I gave up.