The style is correct but its not being read by the browser. The console is showing an error loading the styles from Simple Custom CSS: “Resource interpreted as Stylesheet but transferred with MIME type text/html”.
So in fact none of the styles in SCC are being applied. For example, the first style in the set applies a background image to the about us section on the front page: Rough-Dark-Brown-Paper-Texture.jpg. This is the section titled “Social Media Users”. However, the background remains black. The second style concerns the body font – this is also not applied.
Reading round, this error seems to be a server mis-configuration issue, and others have tied it to cloudfront which I think you are using.
But life’s too short to get that working, just try putting everything that’s in Simple Custom CSS into the field at:
Dashboard > Appearance > Customise > Additional CSS
Let’s look at the columns if we can find a way getting custom css to take effect.