代码示例:(标识:bs_flex-align-self-stretch-responsive)
<!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>对齐拉伸自身(默认)</h2>
  <p>使用 .align-self-*-stretch 类在不同屏幕上的 flex 容器中拉伸 flex 项目。</p>

  <p><code>.align-self-stretch</code>:</p>
  <div class="d-flex bg-light" style="height:150px">
    <div class="p-2 border">Flex item 1</div>
    <div class="p-2 border align-self-stretch">Flex item 2</div>
    <div class="p-2 border">Flex item 3</div>
  </div>
  <br>

  <p><code>.align-self-sm-stretch</code>:</p>
  <div class="d-flex bg-light" style="height:150px">
    <div class="p-2 border">Flex item 1</div>
    <div class="p-2 border align-self-sm-stretch">Flex item 2</div>
    <div class="p-2 border">Flex item 3</div>
  </div>
  <br>

  <p><code>.align-self-md-stretch</code>:</p>
  <div class="d-flex bg-light" style="height:150px">
    <div class="p-2 border">Flex item 1</div>
    <div class="p-2 border align-self-md-stretch">Flex item 2</div>
    <div class="p-2 border">Flex item 3</div>
  </div>
  <br>

  <p><code>.align-self-lg-stretch</code>:</p>
  <div class="d-flex bg-light" style="height:150px">
    <div class="p-2 border">Flex item 1</div>
    <div class="p-2 border align-self-lg-stretch">Flex item 2</div>
    <div class="p-2 border">Flex item 3</div>
  </div>
  <br>

  <p><code>.align-self-xl-stretch</code>:</p>
  <div class="d-flex bg-light" style="height:150px">
    <div class="p-2 border">Flex item 1</div>
    <div class="p-2 border align-self-xl-stretch">Flex item 2</div>
    <div class="p-2 border">Flex item 3</div>
  </div>
  <br>
  <br>

  <p><code>.align-self-xxl-stretch</code>:</p>
  <div class="d-flex bg-light" style="height:150px">
    <div class="p-2 border">Flex item 1</div>
    <div class="p-2 border align-self-xxl-stretch">Flex item 2</div>
    <div class="p-2 border">Flex item 3</div>
  </div>
  <br>
</div>

</body>
</html>
运行结果: