CSS Container Queries: The Future of Responsive Components

CSS Container Queries are a game-changer for responsive design. Unlike media queries that respond to viewport size, container queries allow components to adapt based on their container's size, enabling truly modular and reusable components.

Understanding Container Queries

Container queries solve a fundamental limitation of media queries: components that need to work in different contexts (sidebar, main content, modal) can now adapt to their immediate container rather than the viewport.

Basic Syntax

/* Define a container */
.card-container {
	container-type: inline-size;
	container-name: card;
}

/* Query the container */
@container (min-width: 400px) {
	.card {
		display: grid;
		grid-template-columns: 150px 1fr;
		gap: 1rem;
	}
}

/* Named container query */
@container card (min-width: 400px) {
	.card-title {
		font-size: 1.5rem;
	}
}

Container Types

1. Inline-Size Container

.container {
	container-type: inline-size;
	/* Queries can check width (inline-size) */
}

2. Size Container

.container {
	container-type: size;
	/* Queries can check both width and height */
	/* Note: This may affect layout */
}

3. Normal Container (Default)

.container {
	container-type: normal;
	/* Only style queries allowed, no size queries */
}

Container Query Units

New viewport-relative units for container queries:

.element {
	/* Container query units */
	width: 50cqw; /* 50% of container query width */
	height: 80cqh; /* 80% of container query height */

	/* Logical units */
	padding: 2cqi; /* 2% of container query inline size */
	margin: 1cqb; /* 1% of container query block size */

	/* Smallest/largest dimensions */
	font-size: 5cqmin; /* 5% of container's smaller dimension */
	gap: 2cqmax; /* 2% of container's larger dimension */
}

Practical Examples

1. Responsive Card Component

/* Card that adapts to its container */
.card-wrapper {
	container-type: inline-size;
	container-name: card-container;
}

.card {
	background: white;
	border-radius: 8px;
	padding: 1rem;
	box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

/* Small container: Stacked layout */
@container card-container (max-width: 399px) {
	.card {
		text-align: center;
	}

	.card-image {
		width: 100%;
		height: 200px;
		object-fit: cover;
		border-radius: 8px;
	}

	.card-content {
		margin-top: 1rem;
	}

	.card-title {
		font-size: 1.25rem;
	}
}

/* Medium container: Side-by-side layout */
@container card-container (min-width: 400px) and (max-width: 599px) {
	.card {
		display: grid;
		grid-template-columns: 150px 1fr;
		gap: 1rem;
		align-items: start;
	}

	.card-image {
		width: 100%;
		height: 150px;
		object-fit: cover;
		border-radius: 8px;
	}

	.card-title {
		font-size: 1.375rem;
	}
}

/* Large container: Enhanced layout */
@container card-container (min-width: 600px) {
	.card {
		display: grid;
		grid-template-columns: 200px 1fr;
		gap: 1.5rem;
	}

	.card-image {
		width: 100%;
		height: 200px;
		object-fit: cover;
		border-radius: 8px;
	}

	.card-title {
		font-size: 1.75rem;
		margin-bottom: 0.5rem;
	}

	.card-description {
		font-size: 1.125rem;
		line-height: 1.6;
	}

	.card-actions {
		margin-top: 1rem;
		display: flex;
		gap: 1rem;
	}
}

2. Responsive Navigation

.nav-container {
	container-type: inline-size;
	container-name: navigation;
}

.nav {
	display: flex;
	align-items: center;
	padding: 1rem;
	background: #2c3e50;
}

.nav-items {
	display: flex;
	list-style: none;
	margin: 0;
	padding: 0;
}

/* Mobile: Hamburger menu */
@container navigation (max-width: 599px) {
	.nav-items {
		display: none;
	}

	.nav-toggle {
		display: block;
		margin-left: auto;
	}

	.nav-items.active {
		display: flex;
		flex-direction: column;
		position: absolute;
		top: 100%;
		left: 0;
		right: 0;
		background: #2c3e50;
		padding: 1rem;
	}
}

/* Desktop: Full navigation */
@container navigation (min-width: 600px) {
	.nav-toggle {
		display: none;
	}

	.nav-items {
		gap: 2rem;
		margin-left: auto;
	}

	.nav-item a {
		color: white;
		text-decoration: none;
		font-size: 1rem;
		transition: opacity 0.3s;
	}

	.nav-item a:hover {
		opacity: 0.8;
	}
}

3. Adaptive Grid Layout

.grid-container {
	container-type: inline-size;
	container-name: grid;
}

.grid {
	display: grid;
	gap: 1rem;
}

/* Responsive grid based on container width */
@container grid (max-width: 499px) {
	.grid {
		grid-template-columns: 1fr;
	}
}

@container grid (min-width: 500px) and (max-width: 799px) {
	.grid {
		grid-template-columns: repeat(2, 1fr);
	}
}

@container grid (min-width: 800px) and (max-width: 1199px) {
	.grid {
		grid-template-columns: repeat(3, 1fr);
	}
}

@container grid (min-width: 1200px) {
	.grid {
		grid-template-columns: repeat(4, 1fr);
	}
}

4. Article Layout

.article-container {
	container-type: inline-size;
	container-name: article;
}

.article {
	padding: 2rem;
}

/* Narrow container: Mobile-optimized */
@container article (max-width: 599px) {
	.article-header {
		text-align: center;
	}

	.article-title {
		font-size: clamp(1.5rem, 5cqw, 2rem);
		line-height: 1.2;
	}

	.article-meta {
		flex-direction: column;
		align-items: center;
		gap: 0.5rem;
	}

	.article-content {
		font-size: 1rem;
		line-height: 1.7;
	}

	.article-image {
		width: 100%;
		margin: 1rem 0;
	}
}

/* Wide container: Desktop-optimized */
@container article (min-width: 600px) {
	.article-title {
		font-size: clamp(2rem, 4cqw, 3rem);
	}

	.article-meta {
		display: flex;
		justify-content: space-between;
		align-items: center;
	}

	.article-content {
		font-size: 1.125rem;
		line-height: 1.8;
		max-width: 65ch;
		margin: 0 auto;
	}

	.article-image {
		float: left;
		width: 40%;
		margin: 0 2rem 1rem 0;
	}
}

Advanced Techniques

1. Combining with CSS Variables

.dynamic-container {
	container-type: inline-size;
	--container-padding: clamp(1rem, 3cqw, 3rem);
	--font-scale: clamp(0.875, 0.5cqw, 1.25);
}

@container (min-width: 400px) {
	.dynamic-content {
		padding: var(--container-padding);
		font-size: calc(1rem * var(--font-scale));
	}
}

2. Container Query with Aspect Ratio

.aspect-container {
	container-type: size;
	aspect-ratio: 16 / 9;
}

@container (aspect-ratio > 1) {
	.content {
		/* Landscape layout */
		display: grid;
		grid-template-columns: 1fr 1fr;
	}
}

@container (aspect-ratio <= 1) {
	.content {
		/* Portrait layout */
		display: flex;
		flex-direction: column;
	}
}

3. Nested Container Queries

.outer-container {
	container-type: inline-size;
	container-name: outer;
}

.inner-container {
	container-type: inline-size;
	container-name: inner;
}

/* Query outer container */
@container outer (min-width: 800px) {
	.outer-content {
		display: grid;
		grid-template-columns: 300px 1fr;
	}
}

/* Query inner container */
@container inner (min-width: 400px) {
	.inner-content {
		columns: 2;
		gap: 2rem;
	}
}

4. Style Queries (Future)

/* Note: Style queries are still experimental */
@container style(--theme: dark) {
	.component {
		background: #1a1a1a;
		color: white;
	}
}

@container style(--layout: compact) {
	.component {
		padding: 0.5rem;
		font-size: 0.875rem;
	}
}

Real-World Component Library

/* Base container setup */
.component-container {
	container-type: inline-size;
}

/* Button component */
@container (max-width: 199px) {
	.btn {
		padding: 0.5rem 1rem;
		font-size: 0.875rem;
	}

	.btn-group {
		flex-direction: column;
		width: 100%;
	}

	.btn-group .btn {
		width: 100%;
	}
}

@container (min-width: 200px) {
	.btn {
		padding: 0.625rem 1.25rem;
		font-size: 1rem;
	}

	.btn-group {
		display: flex;
		gap: 0.5rem;
	}
}

/* Form component */
@container (max-width: 399px) {
	.form-group {
		margin-bottom: 1rem;
	}

	.form-label {
		display: block;
		margin-bottom: 0.25rem;
	}

	.form-input {
		width: 100%;
		padding: 0.5rem;
	}
}

@container (min-width: 400px) {
	.form-group {
		display: grid;
		grid-template-columns: 150px 1fr;
		gap: 1rem;
		align-items: center;
		margin-bottom: 1.5rem;
	}

	.form-label {
		text-align: right;
	}

	.form-input {
		padding: 0.625rem;
	}
}

/* Data table component */
.table-container {
	container-type: inline-size;
	overflow-x: auto;
}

@container (max-width: 599px) {
	.data-table {
		font-size: 0.875rem;
	}

	.data-table th,
	.data-table td {
		padding: 0.5rem;
	}

	/* Hide less important columns */
	.data-table .optional {
		display: none;
	}
}

@container (min-width: 600px) {
	.data-table {
		font-size: 1rem;
	}

	.data-table th,
	.data-table td {
		padding: 0.75rem 1rem;
	}

	.data-table .optional {
		display: table-cell;
	}
}

Browser Support & Fallbacks

/* Feature detection */
@supports (container-type: inline-size) {
	.container {
		container-type: inline-size;
	}
}

/* Fallback for older browsers */
@supports not (container-type: inline-size) {
	/* Use traditional media queries */
	@media (min-width: 768px) {
		.component {
			/* Desktop styles */
		}
	}
}

Best Practices

1. Name your containers: Use descriptive container names for clarity
2. Start with inline-size: Most use cases only need width queries
3. Avoid size type when possible: It can affect layout calculations
4. Use container units wisely: They're powerful but can be confusing
5. Progressive enhancement: Always provide fallbacks
6. Test in context: Components should work in various container sizes

Container queries represent a paradigm shift in responsive design, enabling truly modular components that adapt intelligently to their environment. Master them to build more flexible and maintainable component systems!