x
 
<!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.jsdelivr.net/npm/bootstrap@5.1.2/dist/css/bootstrap.min.css" rel="stylesheet">
  <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.1.2/dist/js/bootstrap.bundle.min.js"></script>
</head>
<body> 
<div class="container mt-3">
  <h2>等宽</h2>
  <p>在 flex 项目上使用 .flex-fill 可强制它们等宽:</p>
  <div class="d-flex mb-3">
    <div class="p-2 flex-fill bg-info">弹性项目 1</div>
    <div class="p-2 flex-fill bg-warning">弹性项目 2</div>
    <div class="p-2 flex-fill bg-primary">弹性项目 3</div>
  </div>
  <p>Example without .flex-fill:</p>
  <div class="d-flex mb-3 bg-secondary">
    <div class="p-2 bg-info">弹性项目 1</div>
    <div class="p-2 bg-warning">弹性项目 2</div>
    <div class="p-2 bg-primary">弹性项目 3</div>
  </div>
</div>
</body>
</html>