title: Nested grid with pixel measures
body: <p>I'm beggining with singularitygs (and grids systems), and of course I run into problems. Here it is.</p>
  
  <p>I have this HTML markup:</p>
  
  <pre><code>&lt;div id="wrapper"&gt;
    &lt;div id="main"&gt;
      &lt;div id="first-column"&gt;content&lt;/div&gt;
      &lt;div id="second-column"&gt;content2&lt;/div&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I have setup this assymetric grid:</p>
  
  <pre><code>$grids      : 97px 263px 263px 97px;
  $gutters    : 70px;
  </code></pre>
  
  <p>And this scss:</p>
  
  <pre><code>#wrapper {
    @include background-grid;
    width: 930px;
    margin: 0 auto;
  }
  #main {
    //@include background-grid;
    @include grid-span(2, 2); //this element is spanned acros two columns in the middle
  }
  #first-column {
    @include grid-span(1, 1); //should be spanned acros first column in #main
  }
  #second-column {
    @include grid-span(1, 2); //this element should be spanned acros second column in #main
  }
  </code></pre>
  
  <p>The question is how can I makes the inner divs be aware of the fact that #main should have only two columns (and one gutter). Instead it looks like that the #main inherit the default grid setup. </p>
  
  <p>I've tryed lots of options like changing #main grid via @include layout. Or tell the columns to adapt to the correct context by adding <code>@include grid-span(1, 1, 2);</code> (the third number should tell the div that it's in the default grids context. 
  But with no avail. 
  I suspect that the problem is in my px definition of the default grid. Because the inner divs gets lots of time only 1.356% wide, and this look kind of suscpicious to me. Am I right? What can I do?</p>
  
  <p>Thanks for any suggestion.</p>
  
  <p>EDIT:
  I try add the exact px dimension and in combination with adding the nested context its looks like its supossed, but I think thats its not how it should work??</p>
  
  <pre><code>#block-formblock-contact-form {
    @include  grid-span(1, 2, 2);
    width: 263px;
  }
  
  #block-system-main {
    @include  grid-span(1, 1, 2);
    width: 263px;
  }
  </code></pre>