grid-N = (100 - (gap * (N - 1))) / N + '%';
      
        - grid-2 = (100 - (3.5 * (2 - 1))) / 2 + '%' = 48.25%;
 
        - grid-3 = (100 - (3.5 * (3 - 1))) / 3 + '%' = 31%;
 
        - grid-4 = (100 - (3.5 * (4 - 1))) / 4 + '%' = 22.375%;
 
        - grid-5 = (100 - (3.5 * (5 - 1))) / 5 + '%' = 17.2%;
 
        - grid-6 = (100 - (3.5 * (6 - 1))) / 6 + '%' = 13.75%;
 
        - grid-7 = (100 - (3.5 * (7 - 1))) / 7 + '%' = 11.28571428571429%;
 
        - grid-8 = (100 - (3.5 * (8 - 1))) / 8 + '%' = 9.4375%;
 
        - grid-9 = (100 - (3.5 * (9 - 1))) / 9 + '%' = 8%;
 
        - grid-10 = (100 - (3.5 * (10 - 1))) / 10 + '%' = 6.85%;
 
        - Blablablah...