title: using fixed contain-to-grid in nav wrapper adds extra height
body: <p>using Foundation 4, i decided to make the nav bar of my site sticky.  following some examples i found, i wrapped my  section in a  and gave it the classes "fixed" and "contain-to-grid".  the fixed tag results in adding bottom padding to the nav bar equal to what the margin is supposed to be.  when i use chrome, or firefox inspectors i cannot find the css responsible for doing this.  i have added a new line to css to set a max height.  doing this wound up removing the margin that was used to offset the body content.  i feel like i shouldn't have to add this new css rule.  has anyone experienced this, and how did you fix it?</p>
  
  <pre><code>&lt;div class="contain-to-grid fixed"&gt;
      &lt;nav class="top-bar"&gt;
          &lt;ul class="title-area"&gt;
              &lt;!-- Title Area --&gt;
              &lt;li class="name"&gt;
                  &lt;h1&gt;&lt;a href="/" style="background-image: url(/Content/logos/logo_color_105x35.png); text-indent: -119988px; width: 105px; background-repeat: no-repeat; background-position: 50% 50%;"&gt;company&lt;/a&gt;&lt;/h1&gt;
              &lt;/li&gt;
              &lt;li class="toggle-topbar menu-icon"&gt;&lt;a href="#"&gt;&lt;span&gt;Menu&lt;/span&gt;&lt;/a&gt;&lt;/li&gt;
          &lt;/ul&gt;
  
          &lt;section class="top-bar-section"&gt;
              &lt;!-- Left Nav Section --&gt;
  
              &lt;!-- Right Nav Section --&gt;
              &lt;ul class="right"&gt;
                  &lt;li class="divider hide-for-small"&gt;&lt;/li&gt;
                  &lt;li&gt;@Html.ActionLink("Register", "Register", "Account", routeValues: null, htmlAttributes: new { id = "RegisterLink" })&lt;/li&gt;
                  &lt;li class="divider hide-for-small"&gt;&lt;/li&gt;
                  &lt;li&gt;@Html.ActionLink("Sign in", "SignIn", "Account", routeValues: null, htmlAttributes: new { id = "SignInLink" })&lt;/li&gt;
              &lt;/ul&gt;
          &lt;/section&gt;
      &lt;/nav&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>new css rule i added<br>
      .contain-to-grid.fixed{<br>
          max-height:45px;<br>
      }</p>
  
  <p>fiddle
  <a href="http://jsfiddle.net/Emh8P/6/" rel="nofollow">http://jsfiddle.net/Emh8P/6/</a></p>