Tightened up the grid spacing rules, and extended them so their value(s) changed based on viewport width.
Since the selection-type variable was set to the same hex color value as base-font-color, I made selection-type equal to the base-font-color variable, rather than re-use the hex color value a second time.
Tightened up the left padding rules for ol, ul, and dd elements.
Discovered that we weren't yet defining a font-stack for our elements; fixed that.
A rough first-pass at creating a demo-document.
The compiled stylesheet.