代码:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>div居中</title>
<style>
* {
margin:0;
padding:0;
}
.content {
width:400px;
height:400px;
background:orange;
border: 1px solid green;
position:relative;
margin: 100px auto;
}
.nav {
width:80px;
height:80px;
line-height:80px;
text-align:center;
background:green;
margin: auto;
position:absolute;
left: 0;
top: 0;
bottom:0;
right: 0;
}
</style>
</head>
<body>
<div class="content">
<div class="nav">这是内容</div>
</div>
</body>
</html>
效果：
