代码编写

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        .box {
            position: absolute;
            width: 200px;
            height: 200px;
            background-color: pink;
            top: 50%;
            transform: translate(0, -50%);
        }
    </style>
</head>

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

</html>

运行结果

20230905如何让一个盒子垂直居中(css写法)_代码编写

正确操作

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
       html,body{
        width: 100%;
        height: 100%;
        display: flex;
        justify-content: center;
        align-items: center;
       }
       .box{
        width: 200px;
        height: 200px;
        background-color: aqua;
       }
    </style>
</head>

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

</html>

运行结果

20230905如何让一个盒子垂直居中(css写法)_html_02