leonanpereirapinto/ai-utils/tailwindcss

Tailwind CSS Developer Guide

This skill provides guidelines, patterns, and best practices for working with Tailwind CSS v4 in this project.

Quick Reference

For detailed patterns, examples, and checklists, see:

• references/patterns.md - Complete usage patterns, design tokens, and anti-patterns

Core Principles

• Utility-First: Embrace utility-first approach and avoid custom CSS.
• Design Tokens: Always use design system tokens (bg-background, text-foreground) instead of explicit colors (bg-white, text-black).
• Tailwind Variants: Use tailwind-variants (tv) for component styling instead of CVA.
• Mobile-First: Build responsive layouts with mobile-first approach.

Critical: Design Token Usage

To ensure theme switching works correctly:

Always use:

• Backgrounds: bg-background, bg-card, bg-muted, bg-popover
• Text: text-foreground, text-muted-foreground, text-card-foreground
• Borders: border-border, border-input, border-ring
• Actions: bg-primary text-primary-foreground, bg-secondary text-secondary-foreground
• States: bg-destructive text-destructive-foreground, bg-accent text-accent-foreground

Never use: bg-white, text-black, border-gray-200, bg-blue-500

Common Tasks

Component Styling with Tailwind Variants

import { tv } from 'tailwind-variants'
const button = tv({
  base: [
    'inline-flex items-center justify-center rounded-md',
    'text-sm font-medium transition-colors',
    'focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring',
  ],
  variants: {
    variant: {
      default: 'bg-primary text-primary-foreground hover:bg-primary/90',
      outline: 'border border-input hover:bg-accent hover:text-accent-foreground',
    },
    size: {
      default: 'h-10 py-2 px-4',
      sm: 'h-9 px-3 rounded-md',
      icon: 'size-10',
    },
  },
  defaultVariants: {
    variant: 'default',
    size: 'default',
  },
})

Long Class Strings

Break class strings longer than 100 characters into arrays:

// Good: Break into logical arrays
const card = tv({
  base: [
    'relative flex flex-col rounded-xl border border-border',
    'bg-card text-card-foreground shadow-xs transition-colors duration-150',
  ],
})

Responsive Design

// Mobile-first responsive design
<div className="grid grid-cols-1 gap-4 sm:grid-cols-2 md:grid-cols-3 lg:grid-cols-4">
// Container queries (built-in in v4)
<div className="@container">
  <div className="@lg:flex @lg:items-center">

Modern v4 Utilities

<div className="size-10">          {/* Instead of w-10 h-10 */}
<div className="h-dvh">            {/* Dynamic viewport height */}
<div className="grid-cols-15">     {/* Dynamic grid columns */}
<h1 className="text-shadow-md">    {/* Text shadows */}
<div className="bg-(--custom-color)">  {/* CSS variables */}

Anti-Patterns to Avoid

• Don't use @apply except for base styles
• Avoid inline styles when Tailwind has utilities
• Don't create utility classes that duplicate Tailwind
• Never use !important unless absolutely necessary
• Don't construct classes dynamically (bg-${color}-500)

Validation Checklist

Before finishing a task involving Tailwind CSS:

• [ ] Using design tokens instead of explicit colors
• [ ] Long class strings broken into arrays (>100 chars)
• [ ] Using tailwind-variants for component styling
• [ ] Mobile-first responsive approach
• [ ] Run lint checks (pnpm run lint)

For detailed rules, anti-patterns, and configuration examples, see references/patterns.md.