html：
<!DOCTYPE html>
<html >
<head>
<meta charset="UTF-8">
<title>CSS</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<h1>hello CSS!</h1>
<p>css hen 6</p>
</body>
</html>
css：
/* style.css */
h1 {
padding: 10px;
background-color: orange;
border: 1px solid black
}
p {
color: purple
}
