If you’ve tried out our new Microsoft Teams App Studio you’ve probably noticed the “Control library” tab. We developed this library based on feedback from our developer community to simplify the design and development process. Each time we created a new tab we found ourselves copying the same CSS code repeatedly — as you can imagine there were several issues. To resolve these issues, we built a library for common UI elements used in Teams. Using this library will enable your tab to stay consistent with the Teams look and feel.