CSS 定位 - relative
<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8>
<style type="text/css">
* {
margin: 0;
padding: 0;
}
.left {
width: 100px;
height: 100px;
border: 1px solid red;
}
.center {
width: 100px;
height: 100px;
border: 1px solid green;
position: relative;
left: 50px;
top: 50px;
}
.right {
width: 100px;
height: 100px;
border: 1px solid blue;
}
</style>
</head>
<body>
<div class="left"></div>
<div class="center"></div>
<div class="right"></div>
</body>
</html>
