Change posts per page to 12 (fits 1, 2 and 3 columns best)
Properly indent head element in default template
Transpose header and post sections in sass to better match page layout
Add header classes for each post, apply logic to index.html
Import new headers scss file
Add header tags to front matter in posts
Resave header image files
Create 6 posts to test grid
Alter header images
Vertically centre all elements