title: Proper place to define variables used by my erb templates + layouts for HTML styles?
body: <p>I have a local variable in an erb template:</p>
  
  <pre><code>&lt;% thumbnail_width = 50 %&gt;
  </code></pre>
  
  <p>I'm using this for sizing some thumbnail images.</p>
  
  <p>But now I realize that a number of templates will need to access this variable.</p>
  
  <p>Where should I move it to and what type of variable should it be?</p>