text: window.onload = function() {
    var $app = document.getElementById('app');
    var $loading = document.getElementById('loading');
    $app.removeChild($loading);
    var $button = document.createElement('button');
    var $h1 = document.createElement('h1');
    $app.appendChild($h1);
    $app.appendChild($button);
  
    $h1.textContent = '~Angel HTTP/2 server push~';
  
    $button.textContent = 'Change color';
    $button.onclick = function() {
      var color = Math.floor(Math.random() * 0xffffff);
      $h1.style.color = '#' + color.toString(16);
    };
  
    $button.onclick();
  
    window.setInterval($button.onclick, 2000);
  
    var rotation = 0;
    window.setInterval(function() {
      rotation += .6;
      $button.style.transform = 'rotate(' + rotation + 'deg)';
    }, 10);
  };