Container Queries

What Is It?

A container size query adapts a component to its containing element rather than to the entire viewport.

Properties, Tags and Attributes Explained

• container-type: inline-size: Establishes inline-axis size containment so descendants can query the container width.
• @container (min-width: 360px): Applies descendant rules when an eligible ancestor container meets the width condition.

Each example is a complete HTML page. The CSS is inside the head's style element. Use Try in new tab to edit the CSS or HTML, run your changes, and reset the example.

Example 1: Adapt a card

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Container Queries</title>
  <style>
    .host { container-type: inline-size; }
    .card { display: grid; gap: 12px; padding: 16px; background: #e0e7ff; }
    @container (min-width: 360px) { .card { grid-template-columns: 1fr 2fr; } }
  </style>
</head>
<body>
  <div class="host"><article class="card"><strong>CSS</strong><p>A component that adapts to its own available space.</p></article></div>
</body>
</html>

What you see: The card becomes two columns only when its host is wide enough.

Example 2: Small sidebar variant

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Container Queries</title>
  <style>
    .host { container-type: inline-size; max-width: 240px; }
    .card { background: #dcfce7; padding: 12px; }
    @container (min-width: 360px) { .card { padding: 32px; } }
  </style>
</head>
<body>
  <div class="host"><article class="card">Compact card in a narrow host</article></div>
</body>
</html>

What you see: Even in a wide browser, the narrow host keeps the compact padding.

When and Where to Use It

Use container queries for cards reused in both sidebars and full-width content regions.

Common Mistake or Useful Tip

The query styles descendants of the container; it does not use the queried element as its own size container.

Try It Yourself

Increase the second host max-width to 500px and inspect its padding.