Tailwindcss

Spacing

// Padding and Margin
<div class="p-4 m-2">           {/* padding: 1rem, margin: 0.5rem */}
<div class="px-6 py-4">        {/* padding-x: 1.5rem, padding-y: 1rem */}
<div class="mt-8 mb-4">        {/* margin-top: 2rem, margin-bottom: 1rem */}

// Space between children
<div class="space-y-4">        {/* margin-bottom on all but last child */}
  <div>Item 1</div>
  <div>Item 2</div>
</div>

Typography

<h1 class="text-4xl font-bold text-gray-900">Heading</h1>
<p class="text-base font-normal text-gray-600 leading-relaxed">
  Paragraph text with comfortable line height.
</p>
<span class="text-sm font-medium text-blue-600">Label</span>

Colors

// Text colors
<p class="text-gray-900 dark:text-gray-100">Text</p>

// Background colors
<div class="bg-blue-500 hover:bg-blue-600">Button</div>

// Border colors
<div class="border border-gray-300">Box</div>

Responsive Design

Breakpoints

// Mobile-first responsive classes
<div class="w-full md:w-1/2 lg:w-1/3">
  {/* Full width on mobile, half on medium screens, third on large */}
</div>

<h1 class="text-2xl md:text-4xl lg:text-6xl">
  {/* Responsive text sizes */}
</h1>

<div class="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-4 gap-4">
  {/* Responsive grid */}
</div>

Container

<div class="container mx-auto px-4">
  {/* Centered container with horizontal padding */}
</div>

<div class="max-w-7xl mx-auto px-4 sm:px-6 lg:px-8">
  {/* Responsive container padding */}
</div>

Component Patterns

Button

<button class="px-4 py-2 bg-blue-600 text-white font-medium rounded-md hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2 disabled:opacity-50 disabled:cursor-not-allowed transition-colors">
  Click me
</button>

// Variants
<button class="px-4 py-2 border border-gray-300 rounded-md hover:bg-gray-50">
  Secondary
</button>

Card

<div class="bg-white rounded-lg shadow-md overflow-hidden">
  <img src="/image.jpg" alt="" class="w-full h-48 object-cover" />
  <div class="p-6">
    <h2 class="text-xl font-semibold mb-2">Card Title</h2>
    <p class="text-gray-600">Card content goes here.</p>
  </div>
</div>

Form Input

<div class="space-y-2">
  <label htmlFor="email" class="block text-sm font-medium text-gray-700">
    Email
  </label>
  <input
    type="email"
    id="email"
    class="w-full px-3 py-2 border border-gray-300 rounded-md focus:outline-none focus:ring-2 focus:ring-blue-500 focus:border-transparent"
    placeholder="[email protected]"
  />
  <p class="text-sm text-gray-500">We'll never share your email.</p>
</div>

State Variants

Hover, Focus, Active

<button class="bg-blue-500 hover:bg-blue-600 active:bg-blue-700 focus:ring-2 focus:ring-blue-500">
  Interactive Button
</button>

<a href="#" class="text-blue-600 hover:text-blue-800 hover:underline">
  Link
</a>

Group Hover

<div class="group">
  <img src="/image.jpg" class="group-hover:opacity-75 transition-opacity" />
  <p class="group-hover:text-blue-600">Hover the container</p>
</div>

Disabled

<button class="disabled:opacity-50 disabled:cursor-not-allowed" disabled>
  Disabled Button
</button>

Dark Mode

/* Tailwind v4: Configure in app/globals.css */
@import "tailwindcss";

@media (prefers-color-scheme: dark) {
  /* Or use class-based: .dark */
}

// Usage (same as v3)
<div class="bg-white dark:bg-gray-900 text-gray-900 dark:text-gray-100">
  <h1 class="text-gray-900 dark:text-white">Title</h1>
  <p class="text-gray-600 dark:text-gray-400">Description</p>
</div>

Custom Styles

Arbitrary Values

<div class="top-[117px]">           {/* Custom top value */}
<div class="bg-[#1da1f2]">          {/* Custom color */}
<div class="grid-cols-[200px_1fr]"> {/* Custom grid template */}

@apply Directive

/* components/button.css */
.btn-primary {
  @apply px-4 py-2 bg-blue-600 text-white font-medium rounded-md;
  @apply hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-blue-500;
  @apply disabled:opacity-50 disabled:cursor-not-allowed;
}

Configuration

Tailwind v4: CSS-First Configuration

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

@theme {
  /* Custom colors */
  --color-brand-50: #eff6ff;
  --color-brand-100: #dbeafe;
  --color-brand-900: #1e3a8a;

  /* Custom spacing */
  --spacing-128: 32rem;

  /* Custom fonts */
  --font-family-sans: "Inter", sans-serif;

  /* Custom breakpoints */
  --breakpoint-3xl: 1920px;
}

Tailwind v3 Config (Still Supported)

// tailwind.config.js (optional in v4)
module.exports = {
  content: [
    "./app/**/*.{js,ts,jsx,tsx,mdx}",
    "./components/**/*.{js,ts,jsx,tsx,mdx}",
  ],
  theme: {
    extend: {
      colors: {
        brand: {
          50: "#eff6ff",
          100: "#dbeafe",
          900: "#1e3a8a",
        },
      },
      spacing: {
        128: "32rem",
      },
      fontFamily: {
        sans: ["Inter", "sans-serif"],
      },
    },
  },
  plugins: [require("@tailwindcss/forms"), require("@tailwindcss/typography")],
};

Plugins

Official Plugins

npm install @tailwindcss/forms
npm install @tailwindcss/typography
npm install @tailwindcss/aspect-ratio
npm install @tailwindcss/container-queries

// @tailwindcss/forms
<input type="text" class="form-input rounded-md" />

// @tailwindcss/typography
<article class="prose lg:prose-xl">
  <h1>Article Title</h1>
  <p>Content...</p>
</article>

Performance

Automatic Content Detection

Tailwind v4 automatically detects and scans all template files - no content configuration needed.

Build Performance

Tailwind v4 delivers 3.5x faster full builds (~100ms) compared to v3 using modern CSS features like @property and color-mix().

Browser Requirements: Safari 16.4+, Chrome 111+, Firefox 128+

Common Patterns

Centered Content

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

Sticky Header

<header class="sticky top-0 z-50 bg-white border-b">
  <nav>Navigation</nav>
</header>

Grid Layout

<div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">...</div>

Truncate Text

<p class="truncate">This text will be truncated with ellipsis if too long</p>
<p class="line-clamp-3">This text will show max 3 lines with ellipsis</p>

Best Practices

1. Use Consistent Spacing: Stick to Tailwind's spacing scale
2. Responsive by Default: Always consider mobile-first design
3. Extract Components: Avoid repeating long class lists
4. Use Theme Colors: Define custom colors in config, not arbitrary values
5. Leverage @apply Sparingly: Prefer utility classes in JSX
6. Enable Dark Mode: Plan for dark mode from the start
7. Use Plugins: Leverage official plugins for common needs
8. Optimize Production: Ensure purge is configured correctly

Additional Resources

For detailed information, see:

• Utility Patterns
• Component Library
• Configuration Guide