µCSS is a lightweight, themeable CSS framework designed to be simple, semantic, and completely CSS-only.

The principal functionalities of this tool include:

1. CSS-Only and Lightweight Architecture

• Zero Dependencies: It is a pure CSS framework that requires no JavaScript, no build steps, and no complex configuration.

• Small Footprint: The framework is highly optimized, weighing approximately 19 KB gzipped (~120 KB uncompressed).

2. Automatic Semantic Styling

• Classless Base: It styles semantic HTML elements out of the box, meaning standard tags like <button>, <article>, and <nav> look polished without needing to add specific classes for basic usage.

• Instant Polishing: Developers can simply include a single CSS file to instantly transform the visual appearance of their HTML.

3. Extensive Theming and Customization

• 20+ Color Themes: Users can choose from a wide variety of themes (such as Fuchsia, Blue, Amber, and Jade), each delivered as a single swappable CSS file.

• Dark Mode Support: It features a built-in dark mode that can be toggled globally or for specific components using the data-theme="dark" attribute.

• CSS Variables: Everything is built on CSS custom properties, allowing developers to override any variable to fully customize the look and feel.

4. Responsive and Accessible Design

• Mobile-First: Includes a responsive grid system and containers that adapt automatically to any screen size.

• Built-in Accessibility: The framework prioritizes accessibility through keyboard navigation, visible focus states, and support for ARIA attributes.

5. Rich Component Library

• Ready-to-Use UI: It provides 36 pre-styled components, including buttons, cards, modals, tooltips, accordions, toasts, badges, and spinners.

• Functional Elements: The library includes styles for essential interface elements like forms and alerts.

6. Ecosystem Integration

• Companion Tools: It is part of the Digicreon ecosystem and works seamlessly with Temma (a PHP MVC framework) and µJS (a lightweight AJAX navigation library for SPA-like feels).