<!doctype html>
<meta charset="utf-8">
<title>CSS Test reference</title>
<link rel="author" title="Emilio Cobos Álvarez" href="mailto:ecoal95@gmail.com">
<style>
  :root {
    color: green;
  }
</style>
<p>Should be green
<p>Should be green
<p>Should be green
<p>Should be green
<p>Should be green
<p>Should be green
<p>Should be green
<p>Should be green
<p>Should be green