---
name: tailwindcss-responsive
description: "Responsive design utilities in Tailwind CSS v4: default breakpoints (sm/md/lg/xl/2xl), custom breakpoints via @theme, container queries (@container, @md, @lg), and mobile-first patterns. Use when: applying responsive variants at different screen widths, defining a custom breakpoint, or building container-query-based responsive components."
user-invocable: false
---

# Responsive Design

## Default Breakpoints

| Variant | Size | CSS |
|---------|--------|-----|
| `sm:` | 40rem (640px) | `@media (width >= 40rem)` |
| `md:` | 48rem (768px) | `@media (width >= 48rem)` |
| `lg:` | 64rem (1024px) | `@media (width >= 64rem)` |
| `xl:` | 80rem (1280px) | `@media (width >= 80rem)` |
| `2xl:` | 96rem (1536px) | `@media (width >= 96rem)` |

## Custom breakpoint
```css
@theme {
  --breakpoint-3xl: 120rem;
}
/* Usage: 3xl:grid-cols-6 */
```

## Container Queries v4
```html
<div class="@container">
  <div class="@md:grid-cols-2 @lg:grid-cols-3">
    <!-- Responsive to container -->
  </div>
</div>
```

## Mobile-first
```html
<div class="text-sm md:text-base lg:text-lg">
  <!-- Small screens first -->
</div>
```