Tailwind v4 + shadcn/ui Production Stack

Production-tested: WordPress Auditor (https://wordpress-auditor.webfonts.workers.dev) Last Updated: 2025-10-29 Status: Production Ready ✅

⚠️ BEFORE YOU START (READ THIS!)

CRITICAL FOR AI AGENTS: If you're Claude Code helping a user set up Tailwind v4:

Explicitly state you're using this skill at the start of the conversation
Reference patterns from the skill rather than general knowledge
Prevent known issues listed in
```
reference/common-gotchas.md
```
Don't guess - if unsure, check the skill documentation

USER ACTION REQUIRED: Tell Claude to check this skill first!

Say: "I'm setting up Tailwind v4 + shadcn/ui - check the tailwind-v4-shadcn skill first"

Why This Matters (Real-World Results)

Without skill activation:

❌ Setup time: ~5 minutes
❌ Errors encountered: 2-3 (tw-animate-css, duplicate @layer base)
❌ Manual fixes needed: 2+ commits
❌ Token usage: ~65k
❌ User confidence: Required debugging

With skill activation:

✅ Setup time: ~1 minute
✅ Errors encountered: 0
✅ Manual fixes needed: 0
✅ Token usage: ~20k (70% reduction)
✅ User confidence: Instant success

Known Issues This Skill Prevents

tw-animate-css import error (deprecated in v4)
Duplicate @layer base blocks (shadcn init adds its own)
Wrong template selection (vanilla TS vs React)
Missing post-init cleanup (incompatible CSS rules)
Wrong plugin syntax (using @import or require() instead of @plugin directive)

All of these are handled automatically when the skill is active.

Quick Start (5 Minutes - Follow This Exact Order)

1. Install Dependencies

bash

pnpm add tailwindcss @tailwindcss/vite
pnpm add -D @types/node
pnpm dlx shadcn@latest init

2. Configure Vite

typescript

// vite.config.ts
import { defineConfig } from 'vite'
import react from '@vitejs/plugin-react'
import tailwindcss from '@tailwindcss/vite'
import path from 'path'

export default defineConfig({
  plugins: [react(), tailwindcss()],
  resolve: {
    alias: {
      '@': path.resolve(__dirname, './src')
    }
  }
})

3. Update components.json

json

{
  "tailwind": {
    "config": "",              // ← CRITICAL: Empty for v4
    "css": "src/index.css",
    "cssVariables": true
  }
}

4. Delete tailwind.config.ts

bash

rm tailwind.config.ts  # v4 doesn't use this file

The Four-Step Architecture (CRITICAL)

This pattern is mandatory - skipping steps will break your theme.

Step 1: Define CSS Variables at Root Level

css

/* src/index.css */
@import "tailwindcss";

:root {
  --background: hsl(0 0% 100%);      /* ← hsl() wrapper required */
  --foreground: hsl(222.2 84% 4.9%);
  --primary: hsl(221.2 83.2% 53.3%);
  /* ... all light mode colors */
}

.dark {
  --background: hsl(222.2 84% 4.9%);
  --foreground: hsl(210 40% 98%);
  --primary: hsl(217.2 91.2% 59.8%);
  /* ... all dark mode colors */
}

Critical Rules:

✅ Define at root level (NOT inside
```
@layer base
```
)
✅ Use
```
hsl()
```
wrapper on all color values
✅ Use
```
.dark
```
for dark mode (NOT
```
.dark { @theme { } }
```
)

Step 2: Map Variables to Tailwind Utilities

css

@theme inline {
  --color-background: var(--background);
  --color-foreground: var(--foreground);
  --color-primary: var(--primary);
  /* ... map ALL CSS variables */
}

Why This Is Required:

Generates utility classes (
```
bg-background
```
,
```
text-primary
```
)
Without this,
```
bg-primary
```
etc. won't exist

Step 3: Apply Base Styles

css

@layer base {
  body {
    background-color: var(--background);  /* NO hsl() here */
    color: var(--foreground);
  }
}

Critical Rules:

✅ Reference variables directly:
```
var(--background)
```
❌ Never double-wrap:
```
hsl(var(--background))
```

Step 4: Result - Automatic Dark Mode

tsx

<div className="bg-background text-foreground">
  {/* No dark: variants needed - theme switches automatically */}
</div>

Dark Mode Setup

1. Create ThemeProvider

See

reference/dark-mode.md

for full implementation or use template:

typescript

// Copy from: templates/theme-provider.tsx

2. Wrap Your App

typescript

// src/main.tsx
import { ThemeProvider } from '@/components/theme-provider'

ReactDOM.createRoot(document.getElementById('root')!).render(
  <React.StrictMode>
    <ThemeProvider defaultTheme="dark" storageKey="vite-ui-theme">
      <App />
    </ThemeProvider>
  </React.StrictMode>,
)

3. Add Theme Toggle

bash

pnpm dlx shadcn@latest add dropdown-menu

See

reference/dark-mode.md

for ModeToggle component code.

Critical Rules (MUST FOLLOW)

✅ Always Do:

Wrap color values with
hsl()
in
:root
and
.dark

css

--background: hsl(0 0% 100%);  /* ✅ Correct */

Use
@theme inline
to map all CSS variables

css

@theme inline {
  --color-background: var(--background);
}

Set
"tailwind.config": ""
in components.json

json

{ "tailwind": { "config": "" } }

Delete
tailwind.config.ts
if it exists
Use
@tailwindcss/vite
plugin (NOT PostCSS)

Use
cn()
for conditional classes

typescript

import { cn } from "@/lib/utils"
<div className={cn("base", isActive && "active")} />

❌ Never Do:

Put
:root
or
.dark
inside
@layer base

css

/* WRONG */
@layer base {
  :root { --background: hsl(...); }
}

Use
.dark { @theme { } }
pattern

css

/* WRONG - v4 doesn't support nested @theme */
.dark {
  @theme {
    --color-primary: hsl(...);
  }
}

Double-wrap colors

css

/* WRONG */
body {
  background-color: hsl(var(--background));
}

Use
tailwind.config.ts
for theme colors

typescript

/* WRONG - v4 ignores this */
export default {
  theme: {
    extend: {
      colors: { primary: 'hsl(var(--primary))' }
    }
  }
}

Use
@apply
directive (deprecated in v4)

Use
dark:
variants for semantic colors

tsx

/* WRONG */
<div className="bg-primary dark:bg-primary-dark" />

/* CORRECT */
<div className="bg-primary" />

Semantic Color Tokens

Always use semantic names for colors:

css

:root {
  --destructive: hsl(0 84.2% 60.2%);        /* Red - errors, critical */
  --success: hsl(142.1 76.2% 36.3%);        /* Green - success states */
  --warning: hsl(38 92% 50%);               /* Yellow - warnings */
  --info: hsl(221.2 83.2% 53.3%);           /* Blue - info, primary */
}

Usage:

tsx

<div className="bg-destructive text-destructive-foreground">Critical</div>
<div className="bg-success text-success-foreground">Success</div>
<div className="bg-warning text-warning-foreground">Warning</div>
<div className="bg-info text-info-foreground">Info</div>

Common Issues & Quick Fixes

Symptom	Cause	Fix
`bg-primary` doesn't work	Missing `@theme inline` mapping	Add `@theme inline` block
Colors all black/white	Double `hsl()` wrapping	Use `var(--color)` not `hsl(var(--color))`
Dark mode not switching	Missing ThemeProvider	Wrap app in `<ThemeProvider>`
Build fails	`tailwind.config.ts` exists	Delete the file
Text invisible	Wrong contrast colors	Check color definitions in `:root` / `.dark`

See

reference/common-gotchas.md

for complete troubleshooting guide.

File Templates

All templates are available in the

templates/

directory:

index.css - Complete CSS setup with all color variables
components.json - shadcn/ui v4 configuration
vite.config.ts - Vite + Tailwind plugin setup
tsconfig.app.json - TypeScript with path aliases
theme-provider.tsx - Dark mode provider with localStorage
utils.ts -
```
cn()
```
utility for class merging

Copy these files to your project and customize as needed.

Complete Setup Checklist

Vite + React + TypeScript project created
```
@tailwindcss/vite
```
installed (NOT postcss)
```
vite.config.ts
```
uses
```
tailwindcss()
```
plugin
```
tsconfig.json
```
has path aliases configured
```
components.json
```
exists with
```
"config": ""
```
NO
```
tailwind.config.ts
```
file exists
```
src/index.css
```
follows v4 pattern:
- ```
:root
```
  and
```
.dark
```
  at root level (not in @layer)
- Colors wrapped with
```
hsl()
```
- ```
@theme inline
```
  maps all variables
- ```
@layer base
```
  uses unwrapped variables
Theme provider installed and wrapping app
Dark mode toggle component created
Test theme switching works in browser

Advanced Topics

Custom Colors

Add new semantic colors:

css

:root {
  --brand: hsl(280 65% 60%);
  --brand-foreground: hsl(0 0% 100%);
}

.dark {
  --brand: hsl(280 75% 70%);
  --brand-foreground: hsl(280 20% 10%);
}

@theme inline {
  --color-brand: var(--brand);
  --color-brand-foreground: var(--brand-foreground);
}

Usage:

<div className="bg-brand text-brand-foreground">Branded</div>

Migration from v3

See

reference/migration-guide.md

for complete v3 → v4 migration steps.

Component Best Practices

Always use semantic tokens

tsx

<Button variant="destructive">Delete</Button>  /* ✅ */
<Button className="bg-red-600">Delete</Button>  /* ❌ */

Use
cn()
for conditional styling

tsx

import { cn } from "@/lib/utils"

<div className={cn(
  "base-class",
  isActive && "active-class",
  hasError && "error-class"
)} />

Compose shadcn/ui components

tsx

<Dialog>
  <DialogTrigger asChild>
    <Button>Open</Button>
  </DialogTrigger>
  <DialogContent>
    <DialogHeader>
      <DialogTitle>Title</DialogTitle>
    </DialogHeader>
  </DialogContent>
</Dialog>

Dependencies

✅ Install These

json

{
  "dependencies": {
    "tailwindcss": "^4.1.14",
    "@tailwindcss/vite": "^4.1.14",
    "clsx": "^2.1.1",
    "tailwind-merge": "^3.3.1",
    "@radix-ui/react-*": "latest",
    "lucide-react": "^0.545.0",
    "react": "^19.2.0",
    "react-dom": "^19.2.0"
  },
  "devDependencies": {
    "@types/node": "^24.0.0",
    "@vitejs/plugin-react": "^5.0.4",
    "vite": "^7.0.0",
    "typescript": "~5.9.0"
  }
}

❌ NEVER Install These (Deprecated in v4)

bash

# These packages will cause build errors:
npm install tailwindcss-animate  # ❌ Deprecated
npm install tw-animate-css      # ❌ Doesn't exist

If you see import errors for these packages, remove them and use native CSS animations or

@tailwindcss/motion

instead.

Tailwind v4 Plugins

Tailwind v4 supports official plugins using the

@plugin

directive in CSS.

Official Plugins (Tailwind Labs)

Typography Plugin - Style Markdown/CMS Content

When to use: Displaying blog posts, documentation, or any HTML from Markdown/CMS.

Installation:

bash

pnpm add -D @tailwindcss/typography

Configuration (v4 syntax):

css

/* src/index.css */
@import "tailwindcss";
@plugin "@tailwindcss/typography";

Usage:

html

<article class="prose lg:prose-xl dark:prose-invert">
  {{ markdown_content }}
</article>

Available classes:

```
prose
```
- Base typography styles

prose-sm

prose-base

prose-lg

prose-xl

prose-2xl

- Size variants

```
dark:prose-invert
```
- Dark mode styles

Forms Plugin - Reset Form Element Styles

When to use: Building custom forms without shadcn/ui components, or need consistent cross-browser form styling.

Installation:

bash

pnpm add -D @tailwindcss/forms

Configuration (v4 syntax):

css

/* src/index.css */
@import "tailwindcss";
@plugin "@tailwindcss/forms";

What it does:

Resets browser default form styles
Makes form elements styleable with Tailwind utilities
Fixes cross-browser inconsistencies for inputs, selects, checkboxes, radios

Note: Less critical for shadcn/ui users (they have pre-styled form components), but still useful for basic forms.

Common Plugin Errors

These errors happen when using v3 syntax in v4 projects:

❌ WRONG (v3 config file syntax):

// tailwind.config.js
module.exports = {
  plugins: [require('@tailwindcss/typography')]
}

❌ WRONG (@import instead of @plugin):

css

@import "@tailwindcss/typography";  /* Doesn't work */

✅ CORRECT (v4 @plugin directive):

css

/* src/index.css */
@import "tailwindcss";
@plugin "@tailwindcss/typography";
@plugin "@tailwindcss/forms";

Built-in Features (No Plugin Needed)

Container queries are built into Tailwind v4 core - no plugin needed:

tsx

<div className="@container">
  <div className="@md:text-lg">
    Responds to container width, not viewport
  </div>
</div>

❌ Don't install:

@tailwindcss/container-queries

(deprecated, now core feature)

Reference Documentation

For deeper understanding, see:

architecture.md - Deep dive into the 4-step pattern
dark-mode.md - Complete dark mode implementation
common-gotchas.md - All the ways it can break (and fixes)
migration-guide.md - Migrating hardcoded colors to CSS variables

Official Documentation

shadcn/ui Vite Setup: https://ui.shadcn.com/docs/installation/vite
shadcn/ui Tailwind v4 Guide: https://ui.shadcn.com/docs/tailwind-v4
shadcn/ui Dark Mode (Vite): https://ui.shadcn.com/docs/dark-mode/vite
Tailwind v4 Docs: https://tailwindcss.com/docs
shadcn/ui Theming: https://ui.shadcn.com/docs/theming

Production Example

This skill is based on the WordPress Auditor project:

Live: https://wordpress-auditor.webfonts.workers.dev
Stack: Vite + React 19 + Tailwind v4 + shadcn/ui + Cloudflare Workers
Dark Mode: Full system/light/dark support
Version: Tailwind v4.1.14 + shadcn/ui latest (Oct 2025)

All patterns in this skill have been validated in production.

Questions? Issues?

Check
```
reference/common-gotchas.md
```
first
Verify all steps in the 4-step architecture
Ensure
```
components.json
```
has
```
"config": ""
```
Delete
```
tailwind.config.ts
```
if it exists
Check official docs: https://ui.shadcn.com/docs/tailwind-v4

tailwind-v4-shadcn

NPX Install

SKILL.md Content

Tailwind v4 + shadcn/ui Production Stack

⚠️ BEFORE YOU START (READ THIS!)

Why This Matters (Real-World Results)

Known Issues This Skill Prevents

Quick Start (5 Minutes - Follow This Exact Order)

1. Install Dependencies

2. Configure Vite

3. Update components.json

4. Delete tailwind.config.ts

The Four-Step Architecture (CRITICAL)

Step 1: Define CSS Variables at Root Level

Step 2: Map Variables to Tailwind Utilities

Step 3: Apply Base Styles

Step 4: Result - Automatic Dark Mode

Dark Mode Setup

1. Create ThemeProvider

2. Wrap Your App

3. Add Theme Toggle

Critical Rules (MUST FOLLOW)

✅ Always Do:

❌ Never Do:

Semantic Color Tokens

Common Issues & Quick Fixes

File Templates

Complete Setup Checklist

Advanced Topics

Custom Colors

Migration from v3

Component Best Practices

Dependencies

✅ Install These

❌ NEVER Install These (Deprecated in v4)

Tailwind v4 Plugins

Official Plugins (Tailwind Labs)

Typography Plugin - Style Markdown/CMS Content

Forms Plugin - Reset Form Element Styles

Common Plugin Errors

Built-in Features (No Plugin Needed)

Reference Documentation

Official Documentation

Production Example