Sunnyvale has found the blueprint for creating a prosperous downtown. Officials have figured out how to balance retail, housing and offices in the city's core, even with an aggressive plan to build out nearly 1 million square feet of new office space in downtown. Sunnyvale is confident it will attract employers with its live, work and play downtown formula. District 2 Councilmember Alysa Cisneros, who represents downtown, said she heard concerns about the office space while it was being built,