title: In ipython notebook, can't hide table borders as usual
body: <p>The following IPython notebook cell results in a table with a gray background and borders:</p>
  
  <pre><code>from IPython.display import HTML
  s="""
  &lt;style type="text/css"&gt;
    table, td { 
      border-collapse: collapse;
      border-style: hidden;
      background-color: rgb(240,240,240);
      }
    &lt;/style&gt;
  &lt;table&gt;
    &lt;tr&gt;
      &lt;td&gt;a
      &lt;td&gt;b
    &lt;tr&gt;
      &lt;td&gt;c
      &lt;td&gt;d
    &lt;/table&gt;
  """
  h = HTML(s); h
  </code></pre>
  
  <p>but when the same html content (the content of string s) is the entire body of a plain html file, the table has a gray background and no border (as intended). It appears that the border properties don't work correctly in IPython notebook. Any ideas?</p>
  
  <p>Another puzzle: adding a colgroup to the table and a col to the css selector causes everything but the horizontal rule between rows to disappear in IPython notebook.</p>