Landscape viewport fix (i.e. makes it 1024px on landscape iPad, 480px on landscape iPhone)

viewport-fix.js

if (typeof window.orientation !== 'undefined') {
  var viewport = document.querySelector('meta[name=viewport]');
  function isLandscape() {
    return window.orientation === 90 || window.orientation === -90;
  }
  function fixViewport() {
    if (isLandscape()) { viewport.content = 'width=device-height' }
    else { viewport.content = 'width=device-width' }
  }
  fixViewport();
  window.addEventListener('orientationchange', fixViewport);
}