[ElMiko]

Thank you ennudleyarbl and RbnJrg for your help.

And yes, RbnJrg, that's exactly what I was looking for. I'm curious, though, how does the use of "inline-block" differ from float? That is, on the surface, they appear to be doing a visually indistiguishable thing here, but surely there's a subtle difference that I'm not catching. Is it the wrapping behavior of the two elements? I see that they detatch in the Sigil Preview window if it's narrow enough (presumably would do so on, like, a phone screen too), whereas the float (and table) css did not.

Also, is it necessary to define the width for the col2 span? I've tried toggling it on and off, and it doesn't seem to affect the wrapping behavior one way or another...