Where is the X Theme's CSS?

Help…
I switched to X. I wanted to make some simple changes. I open the editor to the Style CSS and what’s there but a page with a paragraph of information relating to X and absolutely no code after. Where is the CSS for X? I was using 2014, had no trouble opening its CSS, all the elements were on the page, but what’s the reason for the X CSS being incomplete? Am I looking in the wrong place? Also, i tried to make a Child Theme for X and when I tested it, it looked nothing like the Integrity stack I was working on. What’s up with that?
I’m a beginner, so I’m sure I could be missing something obvious. Any advice or assistance would be appreciated.

Here’s the site:
http://themetamodern.com/

Thank you again,

Eric