Make custom fluid CSS grids based on whatever madness you want.

grid.py

from decimal import *

getcontext().prec = 6

cols = Decimal(24)
col_size = Decimal(6) # columns should be this many units
gutter = Decimal(1) # with a 1 unit gutter on either side
total_width = Decimal(100)

units = '%'


column_total_width = total_width / cols

unit_width = column_total_width / ((Decimal(2) * gutter) + col_size)

column_width = col_size * unit_width

gutter_width = gutter * unit_width


col_classes = ['.col'+str(i) for i in range(1, cols+1)]
print '{0} {{ padding-left: {1}{2}; padding-right: {1}{2}; }}'.format(
  ', '.join(col_classes),
	gutter_width,
	units
)

for i in range(1, cols+1):
	actual_width = (i * column_width) + \
	    ((i-1) * (gutter_width * 2))
	print '.col{0} {{ width: {1}{2}; }}'.format(i, actual_width, units)

for i in range(1, cols+1):
	actual_width = (i * column_width) + \
	    ((i) * (gutter_width * 2))
	print '.wrap{0} {{ width: {1}{2}; }}'.format(i, actual_width, units)