css/css-ui/outline-005.html

<!doctype html>
<html lang=en>
  <meta charset=utf-8>
  <title>CSS-UI test: outline & border-radius</title>
  <link rel="author" title="Florian Rivoal" href="http://florian.rivoal.net">
  <meta name=flags content="should">
  <meta name=assert content="To the extent that the outline follows the border edge, it should follow the border-radius curve.">
  <!-- Allow slight color differences where the outline and the background intersect -->
  <meta name=fuzzy content="0-2;0-100">
  <link rel="match" href="../reference/ref-filled-green-100px-square.xht">
  <link rel=help href="https://drafts.csswg.org/css-ui-3/#outline-props">
<style>
body > div {
  width: 100px;
  height: 100px;
  overflow: hidden;
  background: red;
  display: table-cell; /* Make a BFC */
}
div > div {
  width: 50px;
  height: 50px;
  margin: 25px;
  background: green;
  border-radius: 100%;
  outline: solid green 100px;
  outline-offset: -1px;
}
</style>

  <p>Test passes if there is a filled green square and <strong>no red</strong>.</p>
  <div><div></div></div>