Tailwindcss Development

Tailwind CSS Development

Documentation

Use search-docs for detailed Tailwind CSS v4 patterns and documentation.

Basic Usage

• Use Tailwind CSS classes to style HTML. Check and follow existing Tailwind conventions in the project before introducing new patterns.
• Offer to extract repeated patterns into components that match the project's conventions (e.g., Blade, JSX, Vue).
• Consider class placement, order, priority, and defaults. Remove redundant classes, add classes to parent or child elements carefully to reduce repetition, and group elements logically.

Tailwind CSS v4 Specifics

• Always use Tailwind CSS v4 and avoid deprecated utilities.
• corePlugins is not supported in Tailwind v4.

CSS-First Configuration

In Tailwind v4, configuration is CSS-first using the @theme directive — no separate tailwind.config.js file is needed:

@theme {  --color-brand: oklch(0.72 0.11 178);}

Import Syntax

In Tailwind v4, import Tailwind with a regular CSS @import statement instead of the @tailwind directives used in v3:

- @tailwind base;- @tailwind components;- @tailwind utilities;+ @import "tailwindcss";

Replaced Utilities

Tailwind v4 removed deprecated utilities. Use the replacements shown below. For opacity, drop the *-opacity-* class and append the value as a modifier on the existing color: bg-blue-500 bg-opacity-50 becomes bg-blue-500/50, text-white text-opacity-75 becomes text-white/75.

Spacing

Use gap utilities instead of margins for spacing between siblings:

<div class="flex gap-8">    <div>Item 1</div>    <div>Item 2</div></div>

Dark Mode

If existing pages and components support dark mode, new pages and components must support it the same way, typically using the dark: variant:

<div class="bg-white dark:bg-gray-900 text-gray-900 dark:text-white">    Content adapts to color scheme</div>

Common Pitfalls

• Using deprecated v3 utilities (bg-opacity-, flex-shrink-, etc.)
• Using @tailwind directives instead of @import "tailwindcss"
• Trying to use tailwind.config.js instead of CSS @theme directive
• Using margins for spacing between siblings instead of gap utilities
• Forgetting to add dark mode variants when the project uses dark mode