title: ::selection pseudo-element outline property
body: <h1>In <a href="http://reference.sitepoint.com/css/pseudoelement-selection#syntax" rel="nofollow noreferrer" title="::selection selector reference">this reference</a></h1>
  <h3>At the bottom of the description,</h3>
  <p>They state that the <code>::selection</code> selector can use the <strong>outline</strong> property, but I haven't been able to get this to work.</p>
  <p>How do I affect <strong>outline</strong> with this selector properly?</p>