Collection
Collection
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title>Document</title>
<style>
*{padding:0;margin: 0;}
.shade{
position: absolute;
width:1920px;
height:1080px;
background-color: black;
opacity: 0.7;
}
.login{
width: 280px;
height:360px;
background-color: lightgoldenrodyellow;
position: absolute;
top:50%;
left:50%;
margin-top: -140px;
margin-left: -180px;
z-index: 99;
}
</style>
</head>
<body>
<div class="shade"></div>
<div class="login">登录窗口</div>
</body>
</html>点击 "运行实例" 按钮查看在线实例
总结：
绝对定位属性（position: absolute;）能够使元素脱离文档流
