Base Ui

You get forms, menus, overlays, sliders, and toasts with full accessibility baked in, but zero styling opinions. The render prop pattern and mergeProps utility let you compose custom components while keeping ARIA attributes and keyboard behavior intact. Use this when you want headless components that work with your design system instead of fighting a premade theme. The skill covers 25+ components and handles the tricky bits like portal positioning, RTL support, and form validation timing. If you're building a component library or need total style control without reinventing accessibility, this is the reference you want.