一、效果图
二、源代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
.box1 {
position: relative;
width: 300px;
height: 200px;
margin-left: 30px;
margin-top: 30px;
padding: 20px;
background-color: red;
border: 20px solid black;
}
.box2 {
position: absolute;
left: 0;
top: 0;
width: 100px;
height: 100px;
background-color: yellow;
}
</style>
</head>
<body>
<div class="box1">
<div class="box2"></div>
</div>
</body>
</html>