What is responsive design?
Responsive design adapts a layout to the available viewport. Given a viewport width and sorted layout breakpoints, return the layout associated with the greatest breakpoint not exceeding that width.
Implement responsive_layout(width, breakpoints), where breakpoints is a list of [minimum_width, layout_name] pairs sorted by minimum width. Return a string. The first breakpoint must have minimum width 0.
breakpoints contains at least one pair.0.def responsive_layout(width, breakpoints):