Worked on the longbridge/gpui-component repository, focusing on enhancing reliability and type-safety in the GPUI scrollbar rendering logic. Addressed a critical bug by resolving a type mismatch in scrollbar size calculations, which previously led to runtime errors and unstable UI behavior across different configurations. The solution involved careful refactoring and conversion of size calculations to appropriate types, ensuring stable and predictable UI performance. Utilized Rust and applied component design and UI development skills to deliver an isolated, low-risk change with clear commit traceability. No new features were introduced, but the work improved codebase hygiene and facilitated safer, more maintainable rollouts.