title: How can I prompt user to rotate device if in a certain mode landscape or portrait, similar to GameInformer App
body: <p>I have a website that is best viewed in Landscape mode. How can I have it so if the user loads the website in landscape mode it is fine but if it loads in Portrait mode or they rotate from Landscape to Portrait mode a image or something popups up taking up the entire screen asking them to rotate back to landscape? Thinking Javascript/jQuery can do this.</p>
  
  <p>I have seen this done on my iPad with the Game Informer app where if the user opens the app in Portrait or rotates from Landscape to Portrait a opaque image pops up asking them to rotate back to landscape. [see iPad screenshot]
  <img src="https://i.stack.imgur.com/9t5BB.png" alt="enter image description here"></p>