title: is it possible to load offline version of site, while sending request to server
body: <p>I have a single page app written in node.js which has a fair amount of javascript and css.</p>
  
  <p>now is it possible to load the offline version of webpage as soon as the url is entered and at the same time send the request to server and wait for response while the offline version is showing a nice splash screen?<br>
  in other words, instead of waiting for the response from server and then render the application, I prefer that browser would render the app while the request is being sent.<br>
  this way the page is loaded instantly(with the splash page) and the time that requests are being sent and responses are being returned, the javascript and css is being loaded which saves some time.
  is this possible with modern technologies? and is it even a good idea?</p>