A collection of themeable web components that enhance native HTML controls and implement WAI-ARIA Authoring Practices Guide patterns where they apply.

Components are fully typed and developed primarily with Lit.

Documentation and component demos

These principles guide every component in the collection. Web applications need fundamental elements that complement the native HTML set. The Custom Elements specification and other modern web APIs clarify how to architect those elements, while exposing the complexity of building components that work across platforms, remain usable by everyone, and work well with existing elements.

Components build on native HTML elements and browser-provided behavior. For example, a <dialog> remains a <dialog>; an <rc-dialog> adds common affordances such as dragging and resizing, plus developer conveniences such as event forwarding. When JavaScript is absent, blocked, or slow, the underlying markup remains semantically meaningful and operable.

Feature detection gates enhanced behavior so components degrade gracefully without throwing errors or becoming unusable.

Form controls associate with forms and labels through their wrapped native elements to preserve operability and accessibility.

Every component implements the corresponding WAI-ARIA Authoring Practices Guide pattern where one exists.

• Components manage ARIA state (role, aria-*) and extra semantic parts
• Keyboard navigation is fully managed
• Focus management behaves as defined / expected
• A11y testing is part of acceptance, not an afterthought

Components do not impose a particular visual system. They ship the structural styling needed for correct layout and behavior, plus sensible user-agent-like defaults that fit alongside native HTML elements.

• Components use CSS system colors where supported, adapting automatically to user color preferences and accessibility settings
• Components encapsulate any default styling
• Components expose public CSS custom properties and CSS parts for granular control of their appearance
• Components support broad theme tokens for quick adoption into existing design systems

• Components use pointer events rather than mouse-only events for touch and stylus support
• Components are fluid, with conservative minimum constraints and sensible sizing analogous to native elements
• Larger components have declarative compact variants for smaller screens

Efficiency matters on the client, where hardware constraints and power use directly affect people.

• Components have minimal bundled size and are available as individual packages to support tree-shaking
• Components avoid heavy synchronous work and event churn on the main thread, using asynchronous and off-thread work where it keeps the experience smooth
• Lit's lightweight reactive update system avoids unnecessary update cycles

Custom elements are framework-agnostic by definition. Components follow web component best-practices so they behave well with React, Vue, Solid, Angular, or no framework at all.

This project uses Yarn 4.x (Berry) workspaces and plug-and-play (PnP).

Vite builds ESM and UMD output plus type declarations. Tests run with Vitest Browser Mode and Playwright. The default local suite uses Chromium; yarn test:full runs Chromium, Firefox, and WebKit sequentially to bound browser-session resource use. CI always runs the full browser matrix. The documentation site uses Docusaurus.

Maintainers should follow the tag-driven npm release guide when versioning or publishing the synchronized workspace packages.

Note: Use the root build script to build all workspace packages in topological order. Rebuild package dependencies before running tests.

Agent guidance is in AGENTS.md. Other agent configuration files are shallow adapters that point to this canonical source of project context.

The rc-markdown-editor toolbar uses Bootstrap Icons by the Bootstrap Authors under the MIT License.

MIT