Summary: This short series on responsive design dives into the basics, principles, and best practices of creating responsive websites. The introduction highlights the importance of responsive design in today's digital landscape. The principles explore fluid grids, flexible images, and media queries, while the building a responsive grid system post delves into popular frameworks like Bootstrap and Foundation. Best practices cover mobile-first approach, performance optimization, and accessibility considerations, and the final post provides helpful tips for testing and debugging responsive websites across different devices and screen sizes.