Alan Spillane developed a styling enhancement for the momentum-design/momentum-ui repository, focusing on web components in July 2025. He implemented ::part pseudo-element support for the radio button input, enabling external styling from outside the shadow DOM with a single, stable attribute. This approach simplified theming and customization for clients and design teams, aligning with broader design-system goals for portability and reduced handoff time. Alan used TypeScript and front end development skills to ensure seamless integration and maintain traceability through ticket-linked commits. The work addressed cross-brand theming challenges and provided a maintainable solution for external UI adaptation without introducing bugs.