e classes.  This is fine.  Just as we rely on
multiple techniques for managing re-use in our JavaScript or Ruby code, so it is with CSS.</p>
<h3>Design System</h3>
<p>Brut’s <em>design system</em> is a set of <em>custom properties</em>.  They work together to define a basic grid, a modular scale, and a
color palette. You can change this easily by changing the value of the custom properties.</p>
<h3>Single Purpose Classes</h3>
<p>Brut includes <em>single-purpose classes</em> that apply common values for co