<!doctype html>
<meta charset=utf-8>
<style>
  body {
    margin: 0;
    padding: 0;
  }
  iframe {
    vertical-align: top;
  }
</style>
<body>
<div style="width:100px; height:100px; background:green"></div>

<div style="margin:20px">
<iframe id="b" style="width:250px; height:250px; border:10px solid black" src="https://example.org/browser/devtools/client/shared/test/doc_layoutHelpers_getBoxQuads2-b-and-d.html">
</iframe><iframe id="d" style="width:250px; height:250px; border:0; padding:40px" src="https://example.org/browser/devtools/client/shared/test/doc_layoutHelpers_getBoxQuads2-b-and-d.html">
</iframe>
</div>
</body>
