<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>无标题文档</title>
<style type="text/css">
#apDiv1 {
position: absolute;
width: 200px;
height: 115px;
z-index: 1;
left: 107px;
top: 121px;
background-color: #CCCCCC;
}
#lab_id:before{
content: '1';
background-color:yellow;
}
#lab_id:after{
content: '2';
background-color:gray;
}
#checked_1:checked~label{
background-color:red;
}
#checked_1:checked~label:before{
background-color:blue;
}
#checked_1:checked~label:after{
background-color:pink;
}
</style>
</head>
<body>
<div id="apDiv1">
<input id="checked_1" type="checkbox" />
<label id="lab_id" for="checked_1">a</label>
</div>
</body>
</html>