通过flex让一个子盒子水平和垂直居中通过flex让一个子盒子水平和垂直居中通过flex让一个子盒子水平和垂直居中通过f

<!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>
        * {
            margin: 0;
            padding: 0;
        }

        .box {
            width: 500px;
            height: 500px;
            display: flex;
            justify-content: center;
            align-items: center;
            background-color: pink;
        }

        .box>div {
            width: 100px;
            height: 100px;
            background-color: skyblue;
        }
    </style>
</head>

<body>
    <div class="box">
        <div></div>
    </div>
</body>

</html>