| Size: 430 Comment: Clearfix | Size: 496 Comment: Add more block widths | 
| Deletions are marked like this. | Additions are marked like this. | 
| Line 3: | Line 3: | 
| * 40em =~ 640px * 50em =~ 800px * 64em =~ 1024px | * 20 em ≈ 320px * 30 em ≈ 480px * 40 em ≈ 640px * 50 em ≈ 800px * 60 em ≈ 960px * 64 em ≈ 1024px | 
