W3Schools Tryit Editor

<!DOCTYPE html>
<html lang="en">
<title>W3.CSS</title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://www.w3schools.com/w3css/6/w3.css">
<body class="w3-container">

<h2>Toggle Visibility</h2>
<p>Click the button to show or hide the details panel.</p>
<p>JavaScript adds or removes <b>w3-show</b> while the panel keeps its <b>w3-hide</b> class.</p>
<p>You can also use Tab to focus the button and press Enter or Space.</p>

<button class="w3-button w3-teal" onclick="toggleVisibilityDemo(this)">Show or hide details</button>

<div id="visibilityDemo" class="w3-panel w3-pale-blue w3-hide">
  <h3>More Details</h3>
  <p>This panel is now visible.</p>
</div>

<p>This paragraph moves down when the panel appears.</p>

</body>
</html>