Tailwind CSS Development

This skill provides guidance for styling applications with Tailwind CSS, focusing on always using the latest version and modern patterns.

> Philosophy: Use CSS-first configuration with @theme. Use OKLCH colors for perceptual uniformity. Prefer @container queries over media queries when appropriate.

Quick Reference

| Feature | Modern Approach | Legacy (Avoid) | |---------|----------------|----------------| | Configuration | CSS @theme directive | tailwind.config.js | | Colors | OKLCH color space | RGB/HSL colors | | Container queries | @container | Media queries only | | Content detection | Automatic | Manual content: [] config | | PostCSS plugin | @tailwindcss/postcss | tailwindcss package |

Installation (Next.js)

bash
npm install tailwindcss @tailwindcss/postcss postcss

js
// postcss.config.mjs
export default {
  plugins: {
    '@tailwindcss/postcss': {}
  }
}

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

CSS-First Configuration

The @theme Directive

Define your design system directly in CSS:

css
@import "tailwindcss";

@theme {
  /* Colors */
  --color-brand: oklch(0.6 0.15 250);
  --color-brand-light: oklch(0.8 0.1 250);
  --color-brand-dark: oklch(0.4 0.15 250);

  /* Fonts */
  --font-display: "Cal Sans", sans-serif;
  --font-body: "Inter", system-ui, sans-serif;

  /* Spacing */
  --spacing-18: 4.5rem;
  --spacing-128: 32rem;

  /* Border radius */
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;

  /* Shadows */
  --shadow-soft: 0 4px 12px oklch(0 0 0 / 0.08);

  /* Animations */
  --animate-fade-in: fade-in 0.3s ease-out;
}

@keyframes fade-in {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: translateY(0); }
}

Use in HTML:

html
<div class="bg-brand text-white font-display p-18 rounded-xl shadow-soft animate-fade-in">
  Styled with custom theme
</div>

OKLCH Color System

OKLCH provides perceptually uniform colors:

css
@theme {
  /* Primary palette */
  --color-primary-50: oklch(0.98 0.01 250);
  --color-primary-100: oklch(0.95 0.03 250);
  --color-primary-200: oklch(0.90 0.06 250);
  --color-primary-300: oklch(0.82 0.10 250);
  --color-primary-400: oklch(0.70 0.14 250);
  --color-primary-500: oklch(0.60 0.16 250);
  --color-primary-600: oklch(0.50 0.14 250);
  --color-primary-700: oklch(0.40 0.12 250);
  --color-primary-800: oklch(0.30 0.08 250);
  --color-primary-900: oklch(0.20 0.05 250);
  --color-primary-950: oklch(0.12 0.03 250);

  /* Semantic colors */
  --color-success: oklch(0.65 0.15 145);
  --color-warning: oklch(0.75 0.15 85);
  --color-error: oklch(0.55 0.2 25);
}

OKLCH format: oklch(lightness chroma hue)

• Lightness: 0 (black) to 1 (white)
• Chroma: 0 (gray) to ~0.4 (vivid)
• Hue: 0-360 degrees (red=25, yellow=85, green=145, blue=250)

Container Queries

Style based on container size, not viewport:

html
<!-- Define container -->
<div class="@container">
  <!-- Respond to container width -->
  <div class="flex flex-col @md:flex-row @lg:grid @lg:grid-cols-3 gap-4">
    <div class="p-4 @sm:p-6 @md:p-8">
      Content adapts to container
    </div>
  </div>
</div>

Named Containers

html
<div class="@container/sidebar">
  <nav class="block @md/sidebar:flex">
    Navigation
  </nav>
</div>

<div class="@container/main">
  <article class="@lg/main:grid @lg/main:grid-cols-2">
    Main content
  </article>
</div>

Container Breakpoints

| Modifier | Min Width | |----------|-----------| | @xs | 20rem (320px) | | @sm | 24rem (384px) | | @md | 28rem (448px) | | @lg | 32rem (512px) | | @xl | 36rem (576px) | | @2xl | 42rem (672px) |

Dark Mode

Using CSS Variables

css
@theme {
  /* Light mode (default) */
  --color-surface: oklch(0.99 0 0);
  --color-surface-elevated: oklch(1 0 0);
  --color-text: oklch(0.15 0 0);
  --color-text-muted: oklch(0.4 0 0);

  /* Dark mode overrides */
  @variant dark {
    --color-surface: oklch(0.15 0 0);
    --color-surface-elevated: oklch(0.2 0 0);
    --color-text: oklch(0.95 0 0);
    --color-text-muted: oklch(0.7 0 0);
  }
}

html
<div class="bg-surface text-text">
  Automatically adapts to dark mode
</div>

Class-Based Dark Mode

html
<html class="dark">
  <body class="bg-white dark:bg-gray-900 text-gray-900 dark:text-white">
    <button class="bg-gray-100 dark:bg-gray-800 hover:bg-gray-200 dark:hover:bg-gray-700">
      Button
    </button>
  </body>
</html>

Responsive Design

Mobile-First Breakpoints

html
<div class="
  w-full          /* mobile: full width */
  sm:w-1/2        /* ≥640px: half width */
  md:w-1/3        /* ≥768px: third width */
  lg:w-1/4        /* ≥1024px: quarter width */
  xl:w-1/5        /* ≥1280px: fifth width */
">
  Responsive element
</div>

Breakpoint Reference

| Prefix | Min Width | CSS | |--------|-----------|-----| | sm | 640px | @media (min-width: 640px) | | md | 768px | @media (min-width: 768px) | | lg | 1024px | @media (min-width: 1024px) | | xl | 1280px | @media (min-width: 1280px) | | 2xl | 1536px | @media (min-width: 1536px) |

Typography

html
<!-- Headings -->
<h1 class="text-4xl font-bold tracking-tight">Heading 1</h1>
<h2 class="text-3xl font-semibold">Heading 2</h2>
<h3 class="text-2xl font-medium">Heading 3</h3>

<!-- Body text -->
<p class="text-base leading-relaxed">Regular paragraph</p>
<p class="text-sm text-gray-600">Small muted text</p>

<!-- Text styles -->
<span class="font-bold">Bold</span>
<span class="italic">Italic</span>
<span class="underline">Underlined</span>
<span class="line-through">Strikethrough</span>

Flexbox & Grid

Flexbox

html
<!-- Horizontal layout -->
<div class="flex items-center justify-between gap-4">
  <div>Left</div>
  <div>Right</div>
</div>

<!-- Centered content -->
<div class="flex items-center justify-center min-h-screen">
  <div>Centered</div>
</div>

<!-- Wrap items -->
<div class="flex flex-wrap gap-4">
  <div class="flex-1 min-w-[200px]">Item</div>
</div>

Grid

html
<!-- Basic grid -->
<div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
  <div>Item 1</div>
  <div>Item 2</div>
  <div>Item 3</div>
</div>

<!-- Complex layout -->
<div class="grid grid-cols-12 gap-4">
  <aside class="col-span-12 md:col-span-3">Sidebar</aside>
  <main class="col-span-12 md:col-span-9">Main</main>
</div>

<!-- Auto-fill -->
<div class="grid grid-cols-[repeat(auto-fill,minmax(250px,1fr))] gap-4">
  <!-- Items auto-fill available space -->
</div>

States and Variants

html
<!-- Hover, focus, active -->
<button class="
  bg-blue-500
  hover:bg-blue-600
  focus:ring-2 focus:ring-blue-500 focus:ring-offset-2
  active:bg-blue-700
">
  Button
</button>

<!-- Group hover -->
<div class="group">
  <h3 class="group-hover:text-blue-500">Title</h3>
  <p class="group-hover:text-gray-700">Description</p>
</div>

<!-- Peer states -->
<input class="peer" type="checkbox" />
<label class="peer-checked:text-blue-500">Label</label>

<!-- First, last, odd, even -->
<ul>
  <li class="first:pt-0 last:pb-0 odd:bg-gray-50">Item</li>
</ul>

Animations

html
<!-- Built-in animations -->
<div class="animate-pulse">Loading skeleton</div>
<div class="animate-spin">Spinner</div>
<div class="animate-bounce">Bounce</div>
<div class="animate-ping">Ping effect</div>

<!-- Transitions -->
<button class="transition-colors duration-200 ease-in-out hover:bg-blue-600">
  Smooth color change
</button>

<div class="transition-all duration-300 hover:scale-105 hover:shadow-lg">
  Transform on hover
</div>

<!-- Motion preferences -->
<div class="motion-safe:animate-bounce motion-reduce:animate-none">
  Respects user preferences
</div>

Common Patterns

Card

html
<div class="rounded-lg border bg-white p-6 shadow-sm">
  <h3 class="text-lg font-semibold">Card Title</h3>
  <p class="mt-2 text-gray-600">Card description</p>
</div>

Button

html
<button class="
  inline-flex items-center justify-center
  rounded-md bg-blue-500 px-4 py-2
  text-sm font-medium text-white
  hover:bg-blue-600
  focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2
  disabled:opacity-50 disabled:pointer-events-none
">
  Button
</button>

Input

html
<input class="
  w-full rounded-md border border-gray-300 px-3 py-2
  text-sm placeholder:text-gray-400
  focus:border-blue-500 focus:outline-none focus:ring-1 focus:ring-blue-500
  disabled:bg-gray-100 disabled:cursor-not-allowed
" />

Additional Resources

For detailed patterns, see reference files:

• references/theme-directive.md - Complete @theme configuration
• references/colors.md - OKLCH color system deep dive