<html>
<head>
<style type="text/css">
div {
height: 100px;
width: 100px;
background: #ccc;
text-align: center;
}
p {
line-height: 100px;
}
</style>
</head>
<body>
<div>
<p>centered</p>
</div>
</body>
</html>