The Visual Viewport API provides an explicit mechanism for querying and modifying the properties of the window's visual viewport. The visual viewport is the visual portion of a screen excluding on-screen keyboards, areas outside of a pinch-zoom area, or any other on-screen artifact that doesn't scale with the dimensions of a page....It also adds three events, resize , scroll , and scrollend ,...when the visual viewport is resized, scrolls, and finishes a scrolling...