data-attribute.html

<!DOCTYPE html>
<html lang="en">
<head>

  <style>

    .toggle_in{
      color: lightcoral;
    }
    .toggle_out{
      color: darkcyan;
    }
    
  </style>
  
  
  <title>Data</title>
</head>
<body>
  
<nav class="navbar" data-number="0" data-name="navbarlight"></nav>

<nav class="navbar" data-number="1" data-name="navbardark"></nav>

<p class="toggle">color this text<!--demo text-->
</p>

<script src="./data-attribute.js">


</script>


</body>
</html>