I am trying to insert a banner advertisement above the header in the WordPress theme that I am using(dark-mystic-20). I say above the header, because every time I try adding the banner code to the header, the banner shows up, but it seems like the style is lost from the rest of the page. I see content, but it is not properly formatted. I then tried adding it to the index.php file and the banner again appears, but now the search field in the header is moved down and is out of place.
Can anyone offer my any assistance with this? Any help is greatly appreciated.