February 2026 (2026-02) monthly summary focused on upgrading the Tailwind CSS integration in mui/base-ui. Key feature delivered: Tailwind CSS v4 Migration for docs and UI components from v3 to v4, enabling new v4 features and improved compatibility with the design system. The migration was implemented with the primary commit 76d37cd2d258532d1d6616a9747a4e7e2be06210, and included co-authorship from Michał Dudak (as reflected in the commit message). Documentation was updated in tandem to reflect v4 changes, ensuring developers have accurate guidance and that the upgrade path remains maintainable. No major bugs were fixed this month; the effort centered on upgrade work and ensuring compatibility rather than defect resolution. Overall impact: modernized styling foundation, improved alignment with Tailwind CSS v4, reduced technical debt, and prepared base-ui for upcoming features leveraging v4 capabilities. This supports faster UI iteration, consistency across components, and a smoother upgrade path for downstream projects. Technologies/skills demonstrated: Tailwind CSS v4 migration, CSS framework upgrade, documentation migration and guidance, commitment to design-system compatibility, cross-functional collaboration and robust change management.