代码示例：（标识：bs_flex-align-self）
<!DOCTYPE html>
<html lang="en">
<head>
<title>Bootstrap 实例</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link href="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.1.2/css/bootstrap.min.css" rel="stylesheet">
<script src="https://cdn.bootcdn.net/ajax/libs/twitter-bootstrap/5.1.2/js/bootstrap.bundle.js"></script>
</head>
<body>
<div class="p-4">
<h2>自我对齐</h2>
<p>请使用 .align-self-* 类控制指定弹性项目的垂直对齐方式。</p>
<p>.align-self-start:</p>
<div class="d-flex bg-light" style="height:150px">
<div class="p-2 border">弹性项目 1</div>
<div class="p-2 border align-self-start">弹性项目 2</div>
<div class="p-2 border">弹性项目 3</div>
</div>
<br>
<p>.align-self-end:</p>
<div class="d-flex bg-light" style="height:150px">
<div class="p-2 border">弹性项目 1</div>
<div class="p-2 border align-self-end">弹性项目 2</div>
<div class="p-2 border">弹性项目 3</div>
</div>
<br>
<p>.align-self-center:</p>
<div class="d-flex bg-light" style="height:150px">
<div class="p-2 border">弹性项目 1</div>
<div class="p-2 border align-self-center">弹性项目 2</div>
<div class="p-2 border">弹性项目 3</div>
</div>
<br>
<p>.align-self-baseline:</p>
<div class="d-flex bg-light" style="height:150px">
<div class="p-2 border">弹性项目 1</div>
<div class="p-2 border align-self-baseline">弹性项目 2</div>
<div class="p-2 border">弹性项目 3</div>
</div>
<br>
<p>.align-self-stretch (default):</p>
<div class="d-flex bg-light" style="height:150px">
<div class="p-2 border">弹性项目 1</div>
<div class="p-2 border align-self-stretch">弹性项目 2</div>
<div class="p-2 border">弹性项目 3</div>
</div>
<br>
</div>
</body>
</html>
