Frontend work is usually a rather messy job if things are not organized properly from the start. A CSS styleguide is a useful tool for establishing common criteria for the team, in terms of both CSS coding syntax and CSS architecture.
Xcode has a comprehensive SDK that provides everything you need to create beautiful, interactive applications. However, due to its closed-source codebase and no official support for extension hooks it falls short in the realm of social and community supported code. It lacks the flexibility that allows the community to grow and feel at home by adapting and maintaining their own code and tools.