A row with a single line of 12 1-width columns

1
2
3
4
5
6
7
8
9
10
11
12

A row with two lines: a line with a single 12-width column and a line with 2 6-width columns

This div is 12-width column on all screen sizes
6-width column
6-width column

A row with two lines: a line with a single 12-width column and a line with various width columns

This div is 12-columns wide on all screen sizes
1-col
2-col
3-col
6-col
This div is 12-width column
6-width column (offset-by-6)
6-width column (offset-by-3)
 
2-width col
This div is 10-width column