title: position:absolute makes an hr element more than 100% wide
body: <p>In FX and IE the following code makes two bars, but the blue one is slightly wider than the browser screen. Any resizing will leave a horizontal scrollbar with the tail of the blue bar offscreen to the left. This is boiled down from a much larger page and I can't remove the position:absolute element in the original. Can anyone figure out how to make the blue bar only 100% wide so it matches the red one and doesn't cause a horizontal scrollbar? Any ideas what's behind this behavior? I'm stumped. Thanks very much.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false">
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  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;hr style="border:1px solid red; width:100%;"/&gt;
  &lt;hr style="position:absolute; border:1px solid blue; width:100%;" /&gt;</code></pre>
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