I'm using Google Chrome Code coverage tool to extract only the CSS and JS code that is used on the pages but it is not working as expected. The CSS is not considering the @media queries even if I resize the page in all the possible devices:

I also tested the Code coverage tool with jQuery javascript and it also extract only internal functions used, but if you remove the code that is not marked as not used it will not work because they are function and variable declarations that are needed.
Is there another tool to do it easily?