I'm trying to use Susy but I can not create a desirable grid. I want a fixed gutter grid with the gutters coming after the element, not before. I couldn't get that to work. It seems that no matter what I do the elements are too large and the last column falls to the next line.
See this gist: http://sassmeister.com/gist/6ebf5ec14f697f8d137c
In this basic three column layout each 1/3 width column is over 35% wide. What am I missing?