小白一枚，请问大神，当DIV里面的内容足够多的时候机会溢出，怎么处理才能使之自动增加高度，向下撑开？
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>定宽块状元素水平居中</title>
<style>
div{
border:1px solid red;
width:200px;
margin:80px auto;
}
</style>
</head>
<body>
<div>我是定宽块状元素，我要水平居中显示jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj</div>
溢出了</body>
</html>
