title: Why does OpenURI return different HTML content from the original source?
body: <p>I'm trying to get style contents from HTML source using OpenUri and Nokogiri.</p>
  
  <pre><code>require 'open-uri'
  require 'nokogiri'
  require 'css_parser'
  
  url  = open('https://google.com')
  html = Nokogiri::HTML(url)
  css  = CssParser::Parser.new
  css.add_block!(html.search('style#gstyle').text)
  </code></pre>
  
  <p>This returns <code>nil</code>, but the HTML of the Google page contains <code>id="gstyle"</code>. Here is an image of the output result:</p>
  
  <p><a href="https://i.stack.imgur.com/YGJYf.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/YGJYf.png" alt="enter image description here"></a></p>
  
  <ol>
  <li>Why is the Google HTML page, in this example, different from that which OpenUri returns?</li>
  <li>How can I find this tag <code>style#gstyle</code>?</li>
  <li>Why does Firebug see the correct HTML document and OpenUri does not?</li>
  </ol>