Contributed to the vitejs/vite repository by developing a CSS plugin enhancement focused on improving the Stylus Evaluator’s function handling and reliability. This work stabilized the evaluation path for Stylus-based styles, reducing build-time inconsistencies and supporting more dependable CSS builds. The approach involved patch-level fixes and careful plugin development using TypeScript and CSS, with an emphasis on clean commit practices and traceability. By addressing function support within the Stylus Evaluator, the enhancement led to faster debugging and fewer Stylus-related defects. The work demonstrated a strong grasp of front end development principles and attention to maintainable, incremental improvements in open source projects.