Foreword by Mandy Brown: As responsive design evolves, we have a critical need to think about design challenges beyond mobile, tablet, and desktop. When properly designed and planned, design patterns—small, reusable modules—help your responsive layout reach more devices (and people) than ever before. Ethan Marcotte shows you just how that’s done, focusing on responsive navigation systems, resizing and adapting images, managing advertising in a responsive context, and broader principles for designing more flexible, device-independent layouts.