Framework-agnostic Deep Dives Into the Salty CSS Compiler, Decisions, and Trade-offs

A small, framework-agnostic set of deep dives into how Salty CSS works under the hood.

How It Works

• Compiler & Zero-Runtime — how .css.ts files are executed at build time and what actually ships to the client.
• Scoping & Specificity — hash isolation, cascade layers, auto-bumping on extension, and zero-specificity anyOfVariants.
• The Styled API — component factories, TypeScript DX, variants, typed prop tokens, and prop forwarding.

Design Decisions

• Provider-less Theming & RSC — native CSS variables replace ThemeProvider, enabling zero-rerender theming across Server Components and Astro islands.
• Design Philosophy — why Salty CSS chose semantic scoping over atomic CSS, and primitives over pre-baked UI kits.