title: Chrome developer tools window dimensions are inconsistent
body: <p>When you have the Chrome developer tools open, and you resize the window, a small white box appears in the top right corner telling you the dimensions of the window as you resize it. I've marked it with a big green arrow in the screenshot below.</p>
  
  <p>This is a very useful tool, but I've noticed that frequently the values are unexpected and inconsistent with the widths of other elements. For example, when I took the screenshot below, Chrome says the window width is 419px. But if I click the <code>html</code> elements, whose width should be 100%, Chrome tells me <strong>its</strong> width is 404px. This is confusing to me. Why are they different? Is this a bug in Chrome?</p>
  
  <p><img src="https://i.stack.imgur.com/Yss6O.png" alt="Chrome developer tools window size indicator"></p>