Because of what could there be an indent in the header of the site?

Question

Layout

Good afternoon!
Yesterday the programmer set up an rss feed, first on a subdomain, then moved it to the main site. I settled with him, and he left the network - he has a day off.
But then I noticed that there was an indent above the site header, and now the authorization form, when you click on it, slides down somewhere.
I can't figure out what could have happened?

tell?

Answer 1

Ask the programmer / layout designer to resave the page in UTF-8 without BOM.
Due to the UTF-8 encoding with BOM, there is a  symbol that is at the top of the site and creates such an indent.