HTML Code

<!DOCTYPE html>
<html lang="en">
<head>
  <title>@media (max-aspect-ratio: 1/1)</title>
  <style>
    body {
      font-family: Arial, sans-serif;
      margin: 16px;
      color: #0f172a;
    }

    p {
      margin: 0 0 12px;
      max-width: 40rem;
      line-height: 1.5;
    }

    .panel {
      padding: 16px;
      background: #64748b;
      color: #fff;
    }

    @media (max-aspect-ratio: 1/1) {
      .panel {
        background: #16a34a;
      }
    }
  </style>
</head>
<body>
  <p>Resize until the viewport is 1:1 or taller.</p>
  <div class="panel">Phone layout</div>
</body>
</html>

Lines: 0 | Characters: 0

Live Preview Auto-refresh on Run

CSS aspect-ratio Media Feature — max-aspect-ratio