CSSprimarily

CSSprimarily is a design approach for organizing CSS around a central, primary stylesheet that encodes a project's core visual system. In this model, the core stylesheet defines design tokens, typographic scales, color palettes, spacing rules, and component primitives, while additional stylesheets or modules layer on top to handle variants, theming, and page‑specific adjustments.

Key ideas include the use of CSS custom properties (variables) to enable runtime theming, a single source of truth for tokens, and a disciplined naming scheme that reduces duplication. The approach emphasizes separation of concerns by keeping layout, typography, and color decisions consistent across the codebase and by allowing token changes to cascade throughout the site.

Implementation usually starts with a core file that declares variables for colors, type scales, and spacing, followed by component styles that consume those tokens. Breakpoints and accessibility considerations are defined early, and optional utility or helper styles are kept lean to avoid fragmentation. The cascade is used deliberately to permit overrides while preserving a stable core.

Benefits include consistency, easier maintenance, and simpler theming. Potential drawbacks include a larger initial CSS footprint, the need for careful organization to avoid specificity conflicts, and a learning curve for teams accustomed to alternative architectures such as utility-first or component-scoped CSS.

CSSprimarily is compatible with other approaches and can be used alongside design-token workflows, theme switching, and CSS-in-JS for hybrid projects. It is not a formal standard but rather a conceptual framework for structuring CSS at scale.

See also: design tokens, CSS variables, CSS architecture, theming, design system.