老师，这样正确吗？

来源：3-12 编程练习

weixin_慕斯卡1279472

2020-11-26 16:31:48

<!DOCTYPE html>
<html>

<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<style>
.page {
text-align: center;
}

.page .ad {
width: 224px;
height: 364px;
position: fixed;
top: 50%;
margin-top: -182px;
}

.page .left-ad {
left: 0;
}

.page .right-ad {
right: 0;
}
</style>
</head>

<body>
<div class="page">
<img src="http://climg.mukewang.com/59c9f7ce0001839219034033.png" alt="">
<img src="http://climg.mukewang.com/5a3383d00001a3dd02240364.png" alt="" class="left-ad ad">
<img src="http://climg.mukewang.com/5a3383c70001f1b702240364.png" alt="" class="right-ad ad">
</div>
</body>

</html>