Any span in Susy potentially has 1 or 2 attached side gutters. A default Susy span doesn't include any of these, but margins/padding often do include them, and it is sometimes useful to span more gutters than the default. The three options are no-side-gutters (most common), 1-side-gutter (somewhat common), or 2-size-gutters (least common). This is true whether you have the gutters inside (as padding) or outside (as margins):
Susy 1, and all the Susy 2 alphas so far have only supported the first 2 options:
- width-1:
columns()
[function] - width-2:
space()
[function]