Responsive design enhances user experience by adapting layout and content to different display factors. However, existing tools for authoring responsive design primarily adapt to screen width only, and they either rely on predefined templates or require significant manual effort. To expedite responsive design creation, we introduce an authoring tool called DocDancer. DocDancer supports creating ultra-responsive documents where both layout and content adapt to multiple factors (screen width, font properties, customer segments, etc), and provides layout suggestions based on user-provided content and popular responsive patterns. A comparative user study with 16 participants shows that authoring responsive documents in DocDancer takes significantly less time and effort than a commercial tool.