a basic grid system ?

• usually it's based on the 960.gs system
• it has 12 columns
• colums are contained in a row
• a row is contained in a container
• you usually have 4 mobile break points which override the previous hierarchical lg -> md -> sm -> xs | l -> m -> s -> x
• you have to be able to define offset to the left or right based on the view and hierarchy
• they have to be composable md-4 + md-offset-left-4 so as atomic as possible
• since you usually work in percentages you have 2 basic types -> fluid (full width) and the 1024px - scrollbar container ~ 955px so it works on a 15" monitor

I forgot something for sure but those are my first thoughts.