例如：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
<style type="text/css">
p{
text-align: center;
font-family: helvetica,arial,sans-serif;
font-size: 80px;
font-weight: bold;
text-shadow: 0.1em 0.1em #ccc;
}
</style>
</head>
<body>
<p>Hello World</p>
</body>
</html>