title: Does floating point length value make sense on pixel unit?
body: <p>When I try write stylish CSS for <a href="http://forums.asterisk.org/viewtopic.php?f=1&amp;t=81808" rel="noreferrer">forums.asterisk.org</a> site, I saw they use floating point length value on <a href="http://www.w3.org/TR/CSS2/syndata.html#length-units" rel="noreferrer">pixel unit</a>, for example: <code>font-size: 13.1px;</code>.</p>
  
  <p>As far as I known, pixel is the smallest unit in screen, so does floating point length value make sense on pixel unit？</p>
  
  <h2>Screenshot</h2>
  
  <p><img src="https://i.stack.imgur.com/yY95h.png" alt="forums.asterisk.org site use floating point length value on pixel unit"></p>