试一试 - W3.CSS alerts

<!DOCTYPE html>
<html>
<title>W3.CSS</title>
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="/lib/w3.css">
<body class="w3-container">

<h2>Displaying Alerts</h2>

<p>The w3-container class can be use to display alerts.</p>

<p>Alerts are often displayed using a strong color:</p>
<div class="w3-container w3-red">
  <h3>Danger!</h3>
  <p>Red often indicates a dangerous or potentially negative action.</p>
</div>

<div class="w3-container w3-orange w3-text-white">
  <h3>Warning!</h3>
  <p>Orange often indicates a warning that might need attention.</p>
</div>

<div class="w3-container w3-yellow">
  <h3>Warning!</h3>
  <p>Yellow often indicates a warning that might need attention.</p>
</div>

<div class="w3-container w3-green">
  <h3>Success!</h3>
  <p>Green often indicates something successful or positive.</p>
</div>

<div class="w3-container w3-blue">
  <h3>Info!</h3>
  <p>Blue often indicates a neutral informative change or action.</p>
</div>

</body>
</html>