Rplicated content doesn't show the CSS style

Please advise.

The subject site: https://newsscouter.com/

When I copy the content of the post in another post or page, it doesn’t reflect the style given in the css.
[The idea is to test the change in design before implementing it on the front – if you look at the site you will get the idea.]

Any ideas what may be going on?

Thank you very much.