I’m trying to achieve something quite tricky in CSS, but also quite “simple” :

Explanation:
Some element with text inside it (unknown width) with 2 elements on each side of it, both occupying the remaining space.
I thought of going with display:table for the container and for the 3 children going display:table-cell but it just doesn’t work, or I don’t know how to use it properly..
Demo playground
HTML
CSS