en cherchant j ai trouver ça
<html>
<head>
<style type="text/css">
h1 {text-align: center }
h1 {color: #000000}
h1 {background-color: #00ff00}
h2 {text-align: left}
h3 {text-align: right}
</style>
</head>
<body>
<h1>This is header 1</h1>
<h2>This is header 2</h2>
<h3>This is header 3</h3>
</body>
</html>