What problem does it solve? Developers migrating to or building with Tailwind CSS v4 often struggle with the shift from JavaScript-based configuration to CSS-first architecture, and lack clear guidance on modern patterns like container queries, OKLCH colors, and design token systems. ## Core Features & Use Cases - CSS-First Configuration: Define themes, colors, spacing, and typography using the @theme directive instead of tailwind.config.js. - Modern Responsive Patterns: Apply container queries, mobile-first breakpoints, and dark mode strategies for component-level responsive design. - Design Token Architecture: Structure primitive, semantic, and component-level tokens with OKLCH colors for consistent design systems. - Use Case: When building a reusable card component that must adapt to its parent width rather than the viewport, use the container query patterns to define @container on the parent and @md: variants on children. ## Quick Start Ask the AI to refactor a component using Tailwind CSS v4 patterns with CSS-first theme configuration and container queries.