css/css-values/calc-invalid-range-clamping.html

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>
    CSS Values and Units Test:
    Range clamping into calc() expressions
  </title>
  <meta name="assert" content="
    A calc expression can evaluate to a value which is outside the validity range.
    If it does, this value must be clamped into the range.
    The declaration must not be ignored.
  " />

  <link
    rel="author"
    title="François REMY"
    href="mailto:fremycompany.developer@yahoo.fr"
  />

  <link rel="help" href="http://www.w3.org/TR/css3-values/#calc-range"/>

  <link
    rel="match"
    href="reference/200-200-green.html"
  />

  <style type="text/css">

      html, body { margin: 0px; padding: 0px; }

      html { background: white; overflow: hidden; }
      #outer { background: green; width: 200px; height: 200px; }
      #outer { border-radius: 10px; border-radius: calc(-10px); }

  </style>

</head>
<body>

  <div id="outer"></div>

</body>
</html>