相对定位为什么偏移前的位置也改变了？
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>relative样式</title>
<style type="text/css">
#div1{
width:200px;
height:200px;
border:2px red solid;
position:relative;
left:100px;
top:200px;
}
</style>
</head>
<body>
<div id="div1"><span>wo shi ni </span></div>
</body>
</html>
