<!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>块居中</title>
<style>
*{
margin: 0;
padding: 0;
box-sizing: border-box;
}
html,body{/*一定要有这个html的设置，否则 div不会垂直居中对齐*/
height: 100%;
}
body{
display: flex;
height: 100%;
}
.box{
width: 1050px;
height: 600px;
margin: auto;
background-color: aqua;
display: flex;
justify-content: center;
align-items: center;
}
</style>
</head>
<body>
<div class="box">
this is centerabbbcc
</div>
</body>
</html>