styledcomponents

Styled Components is a CSS-in-JS library for styling React and React Native components. It allows developers to write CSS directly in JavaScript by creating styled components—custom components with encapsulated styles that render as normal React components. Each styled component generates a unique class name, ensuring styles are scoped to the component and preventing conflicts.

The library exposes a styled object with properties for HTML tags (for example, styled.div or styled.button). A component can be styled by passing a template literal containing CSS. It also offers utilities such as attrs for setting default props, the css helper for reusing style blocks, createGlobalStyle for applying global CSS rules, and keyframes for animations. The ThemeProvider injects theme values into styled components, enabling consistent theming across an application. Components can read props to conditionally apply styles, and createGlobalStyle can be used to apply global CSS resets.

Styled Components supports React Native via styled-components/native, in addition to web React. It provides support for server-side rendering, with tooling to extract critical CSS during SSR, and can be enhanced by plugins such as babel-plugin-styled-components to improve debugging and minification. The library emphasizes co-locating styles with components and avoiding CSS specificity issues, while automatically handling vendor prefixes.

Pros include improved maintainability, component-scoped styles, dynamic styling through props, and easier collaboration. Cons can include runtime overhead, larger bundle sizes, a learning curve, and potential debugging complexity when class names are minified in production.