During December 2025, Robin Nacken contributed to the nl-design-system/rijkshuisstijl-community repository by implementing Figma Tokens support for calculations and valid CSS output. Robin focused on enabling arithmetic and exponentiation within design tokens, ensuring that generated CSS was both valid and calculable. The work involved developing CSS fixers to address edge cases such as rounding and exponentiation, and introducing unit tests to verify the reliability of token-driven CSS. Using JavaScript, CSS, and build tools, Robin also improved code hygiene by removing deprecated packages and documenting deployment considerations, laying the groundwork for smoother design-to-development handoffs and future maintenance.