Codecademy - Practising CSS (Example 4 - HTML Code)

<!DOCTYPE html>
<html>

<head>
  <title>Specificity</title>
  <link href="style.css" type="text/css" rel="stylesheet">
</head>

<body>
  <div id="container">
    <div id="teal" class="block">
    </div>
    <div id="purple" class="block">
    </div>
  </div>
</body>

</html>