Update

Hi there, this is my first pull request. I hope you like !

I've adjusted this grid to fit better with more modern grids.

That being, rather than having a margin-left of the gutter width. You have it split between a margin-right and margin-left.

E.g.
Previous: margin-left: 2%;
Revised: margin-left: 1%; margin-right: 1%;

What this allows is to have gutter on either side of the container too, but not on the container element itself.

I also removed the negative margin-left on the .grids container and changed it to margin: 0 auto; to center it.

I realise this was based on Harry Robert's Fluid Grid Calculator but there seems to be a 404 on his link. This essentially does the same thing I believe however.