To change the proportions of the items all you need to do is change the proportions of the width and padding-bottom on the .item. Changing the width would affect the number of items on each row, so as to not affect the grid structure we can for example change padding-bottom to 18% to create 16:9 (equivalent to 32:18) rectangles.

demo

• HTML, CSS
• Includes: index.html and CSS file