<!DOCTYPE html>
<!--
     Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/publicdomain/zero/1.0/
--><html><head><title>CSS Test: Test declaring a variable whose value consists of a reference to a variable whose value is "unset".</title>
<link href="mailto:cam@mcc.id.au" rel="author" title="Cameron McCormack">
<link href="http://www.w3.org/TR/css-variables-1/#defining-variables" rel="help">
<link href="support/color-green-ref.htm" rel="match">
<style>
body {
  --b: green;
  color: crimson;
}
p {
  color: red;
}
p {
  color: orange;
  --a: var(--b);
  --b: unset;
  color: var(--a);
}
</style>
</head><body><p>This text must be green.</p>
</body></html>