The Most Important CSS Feature Since Flexbox
For 15 years, responsive design relied on media queries — which only know the viewport size. Container queries let you style based on the size of a parent container. This is transformative for component-based architecture: a card component can adapt its layout based on whether it's in a wide main column or a narrow sidebar, without needing to know about the page layout. Supported in all modern browsers since 2023, container queries are production-ready and underused. Here's how to use them.
Media Queries vs Container Queries
| Media Queries (@media) | Container Queries (@container) |
|---|---|
| Queries the viewport width/height | Queries a parent container's width/height/inline-size |
| Good for: page-level layout (header, sidebar, grid) | Good for: component-level adaptation (cards, forms, lists) |
| Component must know about the page structure | Component is self-contained; works in any layout context |
| Available since 2012 (IE9+) | Available since 2023 (all modern browsers, 95%+ support) |
The Syntax
/* 1. Define a containment context */
.card-wrapper {
container-type: inline-size; /* enables container queries on this element */
container-name: card; /* optional: name for targeting specific containers */
}
/* 2. Query the container */
@container card (min-width: 400px) {
.card {
display: grid;
grid-template-columns: 200px 1fr;
gap: 1rem;
}
}
@container (max-width: 300px) {
.card {
display: block;
}
.card-image {
width: 100%;
}
}
Container Query Units
| Unit | Relative To | Use Case |
|---|---|---|
| cqw | 1% of container width | Font size that scales with card width: font-size: clamp(0.9rem, 3cqw, 1.5rem) |
| cqh | 1% of container height | Element height proportional to container |
| cqi | 1% of container inline size | Logical property: 1% of width in LTR, height in vertical writing modes |
| cqb | 1% of container block size | Logical property: 1% of height in LTR |
| cqmin / cqmax | min/max of cqi and cqb | Ensure elements fit in either dimension |
Real-World Patterns
Pattern 1: Adaptive Card Layout. The classic container query use case. A card displays vertically in a narrow container (sidebar) and horizontally in a wide container (main content). The card doesn't need to know where it is — it adapts to the space it's given.
.card-container {
container-type: inline-size;
}
@container (min-width: 350px) {
.card {
flex-direction: row;
align-items: center;
}
.card-thumbnail {
width: 120px;
flex-shrink: 0;
}
}
Pattern 2: Responsive Typography Inside Components. Use cqw units to scale text proportionally within a card, so a card in a wide column has larger text than the same card in a narrow sidebar.
.widget {
container-type: inline-size;
}
.widget-title {
font-size: clamp(1rem, 5cqi, 1.75rem);
}
.widget-body {
font-size: clamp(0.875rem, 3cqi, 1.125rem);
}
Pattern 3: Grid Columns Based on Container Width. Change the number of columns based on container width, not viewport width. A grid of items in a 600px sidebar shows 2 columns; the same grid in a 900px main area shows 3 columns.
.grid-container {
container-type: inline-size;
}
.grid {
display: grid;
grid-template-columns: repeat(1, 1fr);
}
@container (min-width: 400px) {
.grid { grid-template-columns: repeat(2, 1fr); }
}
@container (min-width: 700px) {
.grid { grid-template-columns: repeat(3, 1fr); }
}
Pattern 4: Container Queries + CSS Grid for Page Layouts. Combine container queries with CSS Grid's auto-fit/minmax for truly responsive layouts without media queries. The grid places as many columns as fit; container queries handle the styling inside each grid cell.
.page-grid {
display: grid;
grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
gap: 1.5rem;
}
.page-grid > * {
container-type: inline-size; /* each grid cell is its own container */
}
Style Queries (The Next Frontier)
Beyond container size queries, CSS now supports style queries — querying CSS custom property values:
@container style(--theme: dark) {
.card {
background: #1a1a2e;
color: #e0e0e0;
}
}
Style queries are newer (Chrome 111+, Safari 18+, Firefox support in progress) but are the logical next step: components that adapt not just to size but to any inherited property or custom property. Combined with design tokens as CSS custom properties, this enables fully context-aware components.
When to Still Use Media Queries
Container queries don't replace media queries — they complement them. Still use media queries for: overall page layout (header, navigation, footer), user preference queries (prefers-reduced-motion, prefers-color-scheme, prefers-contrast), and device characteristics (pointer: coarse for touch devices, resolution for high-DPI screens). The rule: media queries for page-level concerns, container queries for component-level concerns.
Bottom line: Container queries are the missing piece in component-based CSS. If you build with React, Vue, or Svelte components, start using container queries today — every major browser has supported them for over two years. The old approach of passing "variant" props (variant="compact" vs variant="wide") becomes unnecessary when the component can sense its own container width. See also: CSS Responsive Design Guide and Tailwind vs Bootstrap vs MUI.