Primer CSS Utilities

primer-utilities provides a collection of immutable, atomic CSS utility classes, designed to facilitate rapid UI development. It forms a foundational part of the Primer Design System, originally developed by GitHub to style its own interfaces. The package's philosophy emphasizes single-purpose classes to promote consistency and reduce custom CSS. The current stable version is 5.0.0, published in January 2019. This standalone package is now superseded by modules within the @primer/css monorepo, which represents the actively maintained version of Primer. While primer-utilities@5.0.0 remains available on npm, it is no longer actively developed or directly maintained as a separate entity.