UI systems & component libraries
Overview
UI systems bundle design tokens, components (buttons, dialogs, tables), and documentation so product teams ship consistent interfaces faster. They may be CSS-first (Bootstrap, Tailwind), React-centric (MUI, Radix + shadcn), or tied to a vendor design language.
Key concepts
- Design tokens — Color, type, spacing, radii as data or CSS variables.
- Primitives vs patterns — Low-level controls vs composed flows (wizard, data table).
- Accessibility — Focus management, ARIA, keyboard support built into primitives.
- Theming — Light/dark, brand swaps, density modes.
- Versioning — Semver, codemods, and migration guides for breaking changes.
Adoption flow
Sample: Tailwind-style utility usage (illustrative)
<button
class="rounded-md bg-indigo-600 px-4 py-2 text-sm font-medium text-white hover:bg-indigo-500"
type="button"
>
Primary action
</button>
References
- W3C — Design Tokens Community Group
- MDN — Accessibility
- Library docs in this section — Bootstrap, Tailwind CSS, shadcn/ui