<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>z-index</title>
  <link rel="stylesheet" href="style.css" />
</head>
<body>
  <header class="page-header">
    <h1>z-index</h1>
    <p class="lead">Stacking order for positioned elements. Higher = on top.</p>
  </header>
  <main class="demo">
    <div class="stack">
      <div class="layer l1">z=1</div>
      <div class="layer l2">z=2</div>
      <div class="layer l3">z=3 (top)</div>
    </div>
  </main>
</body>
</html>