Bug in 2.8.4

Since 2.8.4 the editor does not use my child theme CSS. In my case I have defined justification via

.entry-content p
	{text-align: justify;}

but in 2.8.4 I have to justify all paragraphs manually.
Rolling back to 2.8.3 solved the problem.

The page I need help with: [log in to see the link]