<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>子元素相对于父元素定位</title>
<style>
.assistor {
position: relative; /*关键点*/
display: block;
width: 500px;
height: 300px;
margin: 100px auto 0 auto;
background-color: #ddd;
}
.parent {
width: 500px;
height: 300px;
background-color: #888;
overflow: auto; /*关键点*/
}
.child {
position: absolute; /*关键点*/
width: 120px;
height: 120px;
margin: 100px 50px;
background-color: #ffff00;
}
.placeholder {
width: 1000px;
height: 1000px;
}
</style>
</head>
<body>
<div class="assistor">
<div class="parent">
<p>我是子元素1</p>
<div class="child">我是子元素2</div>
<div class="placeholder"></div>
</div>
</div>
</body>
</html>
