<!DOCTYPE html>
<html>
<head>
<style> 

body * p {color:red;}
div{border:1px solid green; width: 300px;padding: 10px;}

</style>
</head>
<body>

<div>
<h3>제목</h3>
<p>내용1</p>
<p>내용2</p>
</div>
<p>내용3</p>

</body>

</html>