title: Foundation use offset only for medium screen
body: <p>I have a little problem with Foundation 5 and the grid.</p>
  
  <p>I try to apply an offset only for medium screen, but it seem to apply on large and small screen too.
  There is the code : </p>
  
  <pre><code>&lt;div class="row"&gt;
    &lt;div class="large-6 medium-offset-1 medium-6 columns"&gt;
        &lt;p&gt;Hello world&lt;/p&gt;
    &lt;/div&gt;
    &lt;div class="large-6 medium-5 columns"&gt;
      &lt;div class="right"&gt;&lt;p&gt;Hello world 2&lt;/p&gt;&lt;/div&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>As you can see <code>medium-offset-1</code> is only for medium but the large screen have also the offset...</p>
  
  <p>Why is that ? </p>