This is a little different from the problems i saw on the forum already.
So here it goes.
I have a text block, splited in two span text.
The first span is underlined, and i would like to underline the rest of the text (the 2nd span text) when on hover.
This is a triggered animation that just does an eased bottom-border width of 100% on hover and 30% by default. It does not need multiple spans. You might be able to do this with a css transition, apply that to a unique classname and put that custom css block in your page custom code.