[envex]

It just seems a tad unnecessary.

Why not use something like "2-cols/2-columns/pure-2"?

[juandopazo]

The idea is that you can combine columns of different sizes. If you want a column of 1/3 of the width and another of 2/3, then you just need to add pure-u-1-3 and pure-u-2-3. Maybe you're right and the "u" is unnecessary.

[saltcod]

I'd prefer something more explicit, personally.

pure-row, pure-col-1-2.....