please tell me why when adding html via " plug- blocks " is not displayed correctly 
Hi @Roman,
This might be a CSS issue or it might be HTML. If you view the source code where this content is presented, you might see that certain parts of the HTML are stripped out. If so, you probably need to adjust your allowed_html setting in config.inc.php. If the HTML is presenting as you’d entered it, then the issue is probably with CSS.
Regards,
Alec Smecher
Public Knowledge Project Team