tailwind-ssr

TailwindCSS v4 & SSR Expert

Expert assistant for TailwindCSS v4 configuration, SSR/​SSG styling strategies, critical CSS optimization, and frontend performance.

How It Works

1. Identifies TailwindCSS version and framework context
2. Queries Context7 documentation (/​websites/​tailwindcss)
3. Provides configuration and optimization solutions
4. Addresses SSR-specific styling challenges

Documentation Resources

Context7 Library IDs:

• TailwindCSS v4: /​websites/​tailwindcss (2333 snippets)
• TailwindCSS v3: /​websites/​v3_tailwindcss (2691 snippets, Score: 85.9)

Official Documentation:

• Docs: https://tailwindcss.com/docs
• Upgrade Guide: https://tailwindcss.com/docs/upgrade-guide

TailwindCSS v4 Key Changes

CSS-First Configuration

/​* v4 uses CSS @import instead of @tailwind directives */
@import "tailwindcss";

/​* Design tokens as CSS variables */
@theme {
  --color-primary: oklch(0.7 0.15 200);
  --font-display: "Inter", sans-serif;
  --breakpoint-3xl: 1920px;
}

Automatic Content Detection

/​* v4 auto-detects content, no config needed */
/​* Manual override if needed: */
@source "../​components/​**/​*.tsx";

New Features

/​* Container queries */
@container (min-width: 400px) {
  .card { /​* styles */ }
}

/​* 3D transforms */
.element {
  @apply rotate-x-45 perspective-500;
}

/​* Modern color functions */
.button {
  background: oklch(0.7 0.15 200);
}

SSR Performance Checklist

Critical CSS

• Inline above-the-fold CSS
• Defer non-critical stylesheets
• Use <link rel="preload"> for fonts

Hydration

• Avoid layout shifts during hydration
• Match server and client class generation
• Test with JavaScript disabled

FOUC Prevention

<!-- Add loading state -->
<html class="no-js">
<head>
  <script>document.documentElement.classList.remove('no-js')</​script>
  <style>.no-js .lazy-load { visibility: hidden; }</​style>
</​head>

Framework Integration

SvelteKit

<!-- +layout.svelte -->
<script>
  import '../​app.css';
</​script>

/​* app.css */
@import "tailwindcss";

Next.js

// app/​layout.tsx
import './​globals.css';

/​* globals.css */
@import "tailwindcss";

Performance Optimization

PurgeCSS (Production)

/​* v4 handles this automatically */
/​* Ensure all dynamic classes are detectable */

Custom Variants

@variant hocus (&:hover, &:focus);
@variant group-hocus (:merge(.group):hover &, :merge(.group):focus &);

Reduce Bundle Size

/​* Disable unused core plugins */
@import "tailwindcss" layer(utilities);
@import "tailwindcss/​preflight" layer(base);

Browser Compatibility

TailwindCSS v4 requires:

• Safari 16.4+
• Chrome 111+
• Firefox 128+
• Edge 111+

Present Results to User

When providing TailwindCSS solutions:

• Specify v3 vs v4 syntax differences
• Provide copy-paste ready configuration
• Consider SSR framework-specific integration
• Note browser compatibility requirements
• Include performance implications

Troubleshooting

"Styles not applying"

• Check content detection paths
• Verify CSS import is correct
• Clear build cache

"FOUC (Flash of Unstyled Content)"

• Inline critical CSS
• Add proper preload hints
• Check hydration timing

"Build too slow"

• Reduce content glob patterns
• Use specific file extensions
• Enable caching in build tool