我编写了如下代码:
.box {
background-color: red;
}
.container {
height: 50vh;
background-color: blue;
} <!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">
<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/css/bootstrap.min.css" rel="stylesheet"
integrity="sha384-GLhlTQ8iRABdZLl6O3oVMWSktQOp6b7In1Zl3/Jr59b6EGGoI1aFkw7cmDA6j6gD" crossorigin="anonymous">
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.0-alpha1/dist/js/bootstrap.bundle.min.js"
integrity="sha384-w76AqPfDkMBDXo30jS1Sgez6pr3x5MlQ1ZAGC+nuZB+EYdgRZgiwxhTBTkF7CXvN"
crossorigin="anonymous"></script>
<link rel="stylesheet" href="style.css">
<title>Document</title>
</head>
<body>
<div style="height: 250px; background-color: blue;">
<div class="row d-flex align-items-center justify-content-start">
<div class="col-4">
<div class="box">1</div>
</div>
<div class="col-4">
<div class="box">1</div>
</div>
</div>
</div>
</body>
</html>我的目标是从上到下居中.所以就像这样:
由于某些原因，我编写的代码无法正常工作.我看了文档，但找不到解决方案.我想知道为什么我写的代码框没有居中？
我try 了文档中的示例代码.
