Question: I'm working on an upgrade for our current application (asp.net mvc). Here my problem is, I have a existing css file name "styles.css". Now this file has lots of css classes and they are used in different pages.

Now as a part of the upgrade process, this css file will not be used anymore. But I still want certain css classes from this file, so that I can copy them to a new file and include it in my pages.

Any ideas on how to extract these styles which are used in my new pages. And yes the styles which I want to pick are already set to the controls in the page. Please help.

Answer: 
Use Chrometools Audits

In Chrome Press: `F12` -> `Audits` -> `Run`

It will let you know what is and is not used.

![Chrome Audits](https://i.stack.imgur.com/lDccP.png)
Use a Browser Debugger, click on the elements on site and see on the right corner which classes are machtes and copy them.