On a mobile, this page adjusts automatically to fill the screen, which you can see by rotating the device from portrait to landscape mode. The step and fluid buttons are ineffective. On a mobile, this page adjusts automatically to fill the screen. Similarly on a PC it adjusts to the size of the window. However, as the window on a PC can be dynamically resized, the page dynamically resizes as well. On a device that supports windows, this page demonstrates the step responsive technique whereby the content of the web page responds to changes in the window width in discrete steps instead of incrementally. To see the effect, just grab the side of the window and expand and contract the width. The main navigation menu automatically switches from a vertical side bar to a horizontal presentation. To see the page reformatted incrementally, click the "fluid" button.