<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
body{
width: 100%;
height: 100%;
background: green;
z-index: 1;
}
.wrap{
width: 100%;
height: 100%;
position: relative;
z-index: 3;
background: red;
}
.top{
width: 100px;
height: 50px;
position: absolute;top: 10%;left: 10%;
background: blue;
}
</style>
</head>
<body>
<div class="wrap">
<div class="top"></div>
<div class="bottom"></div>
</div>
</body>
</html>
CodeManDSH
西兰花伟大炮