When you see that CSS file inside the code become 1 line is most likely this CSS file already get minified, it will involves removing any unnecessary spaces from within a file to help reduce its size and thus make it load faster on the site.

By the way, i strongly not recommend that you modify the Easysocial CSS core code, but you can add your custom css code from your site backend > Easysocial > theme > custom css section.

What? So you are saying I, your paying customer needs to go and spend hours removing spaces? Seriously?

Never mind I learned something today... Thank you.

Nope, I am sorry that if i didn't explain properly regarding this in my previous reply.

What my previous reply mean is I trying to explain why that CSS file only show 1 line of code.

When you see the CSS file show 1 line of code is because this CSS file already get compressed.

If you would like to modify the existing CSS code, i would suggest that add your custom css code into your site backend under Easysocial custom css area (screenshot : http://take.ms/omtz1).

Or am i missing anything of your current question? If yes, please do not hesitate to let me know.