I'm learning how to make CSS layouts using Katie's (#106445) free template, and I've got a pretty good understanding of how to do most things in the tutorial (like backgrounds, fonts, panel colors, logo replacing) but I can't figure out how to do the boxes. The coding for the boxes is linked in the tutorial but it doesn't say how or where in the template put it. Has anyone been able to get the boxes working and can show me how??

The template/tutorial I'm using- https://www.lioden.com/topic.php?id=304429485172
The box coding- https://pastebin.com/G0d0WW52

Any help is appreciated!