title: Set fixed gutter in Bourbon Neat
body: <p>By default, Neat uses percentages as the margin-right of each <code>span-columns</code> element, but I'm hoping for a fixed <code>30px</code> gutter, regardless of the <code>outer-container</code> width.</p>
  
  <p><img src="https://i.stack.imgur.com/QZjPj.png" alt="enter image description here"></p>