Video 4 of Building and Designing beautiful websites from scratch.
Link to part 2 of gridding: https://www.youtube.com/watch?v=ViEAsAfBB9I
Link to 12-column-grid: http://s3-us-east-2.amazonaws.com/lam-fall/tutorials/attachments/000/000/004/original/grid-corrected.css?1518632165
source