UnoCSS is an instant atomic CSS engine designed to be flexible and extensible. The core is un-opinionated - all CSS utilities are provided via presets. It's a superset of Tailwind CSS, so you can reuse your Tailwind knowledge for basic syntax usage.
Important: Before writing UnoCSS code, agents should check for uno.config.* or unocss.config.* files in the project root to understand what presets, rules, and shortcuts are available. If the project setup is unclear, avoid using attributify mode and other advanced features - stick to basic class usage.
The skill is based on UnoCSS 66.x, generated at 2026-01-28.
Core
| Topic |
Description |
Reference |
| Configuration |
Config file setup and all configuration options |
core-config |
| Rules |
Static and dynamic rules for generating CSS utilities |
core-rules |
| Shortcuts |
Combine multiple rules into single shorthands |
core-shortcuts |
| Theme |
Theming system for colors, breakpoints, and design tokens |
core-theme |
| Variants |
Apply variations like hover:, dark:, responsive to rules |
core-variants |
| Extracting |
How UnoCSS extracts utilities from source code |
core-extracting |
| Safelist & Blocklist |
Force include or exclude specific utilities |
core-safelist |
| Layers & Preflights |
CSS layer ordering and raw CSS injection |
core-layers |
Presets
Main Presets
| Topic |
Description |
Reference |
| Preset Wind3 |
Tailwind CSS v3 / Windi CSS compatible preset (most common) |
preset-wind3 |
| Preset Wind4 |
Tailwind CSS v4 compatible preset with modern CSS features |
preset-wind4 |
| Preset Mini |
Minimal preset with essential utilities for custom builds |
preset-mini |
Feature Presets
| Topic |
Description |
Reference |
| Preset Icons |
Pure CSS icons using Iconify with any icon set |
preset-icons |
| Preset Attributify |
Group utilities in HTML attributes instead of class |
preset-attributify |
| Preset Typography |
Prose classes for typographic defaults |
preset-typography |
| Preset Web Fonts |
Easy Google Fonts and other web fonts integration |
preset-web-fonts |
| Preset Tagify |
Use utilities as HTML tag names |
preset-tagify |
| Preset Rem to Px |
Convert rem units to px for utilities |
preset-rem-to-px |
Transformers
Integrations
| Topic |
Description |
Reference |
| Vite Integration |
Setting up UnoCSS with Vite and framework-specific tips |
integrations-vite |
| Nuxt Integration |
UnoCSS module for Nuxt applications |
integrations-nuxt |