open_in_new content_copy 
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatib1e" content="IE=edge">
<meta name="viewport" content="width=device-width,initial-scale=1.0">
< link rel="stylesheet" href="style.css">
<title>Document</title>
</head>
<body>
<div>
<p>Lorem ipsum dolor sit amet.</p>
</div>
</body>
</html>

file style.css
p{
text-align:center;
}
div {
height: 400px;
width: 400px;
background-color:yellow;
}