## Rule 12: Use $variables for sizing

Keep a $spacing variable - it keeps your site's paddings, margins and gutterings consistent.
You can make more variables all relative to your main spacing variable too e.g $spacing-half: $spacing / 2
With fonts, this is also a good idea. $fnt-lrg; $fnt-med; $fnt-small; It's easy on big front-end's to end up with random font sizes.
Subtle consistency goes a long way.