Felipe Dalcin contributed targeted UI and styling improvements to the pressbooks/pressbooks-book repository, focusing on code quality and maintainability. He addressed UI text consistency by normalizing contributor label capitalization in the book header, reducing confusion for users and aligning with established conventions. Felipe also fixed chapter numbering and border color handling, refactoring SCSS to separate color logic from shorthand properties for improved theming consistency. His work included a Node.js upgrade to v22, supporting platform modernization. Using SCSS, CSS, and PHP, Felipe demonstrated attention to detail and a methodical approach, delivering low-risk, maintainable solutions that enhanced the reliability of the codebase.