Primitives that stay out of the way, tokens that survive a rebrand, and sections you own outright the moment you paste them in.
Every style resolves at build time. No style recalculation on mount, no cascade of context providers, nothing shipped to parse.
Set a brand hue and a neutral ramp. Every surface, border and label repaints from the same tokens — no per-component overrides.
Focus rings, roving tabindex and ARIA wiring live inside the primitives, so the accessible path is also the shortest one.
Layout, typography and interaction split cleanly. Box owns spacing, Text owns type — nothing reaches across that line.
Sections arrive as source in your repo, not as an import you have to fight. Edit the markup, keep the tokens.
Primitives render on the server unmodified. Client boundaries stay where you put them instead of creeping up the tree.