Structure
Light Roast uses a lot of flexbox, both for the full page columns and the inner sectioned content. The template file should have a good amount of examples for how each element works!
CSS
The fonts used are Rubik Dirt from google fonts and the standard monospace font in most browsers. You can change them if you want, you just want to find the font-family attributes and if you want to port your own over from google you want to get an embed link from Google Fonts (or the font provider of your choice.)
The standard colours use CSS variables (you can poke through the code to figure those out)-- Go ahead and use HTML named colours or HEX or whatever! Obviously, there's a lot of different themes you can go for with this code. Have fun with it!