JavaScript Tutorial

header

<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
    $(document).ready(function(){
      $(":header").css("background-color", "yellow");
    });
</script>
</head>
<body>
    <h1>Welcome to My Homepage</h1>
    <h2>My Fantastic Homepage</h2>
    <h3>It's amazing!</h3>
    <p class="intro">My name is Donald.</p>
    <p>I live in Duckburg.</p>
    <p>My best friend is Mickey.</p>
    <p>Who is your favourite:</p>
    <ul id="choose">
      <li>Goofy</li>
      <li>Mickey</li>
      <li>Pluto</li>
    </ul>
</body>
</html>