I don't know if this is the best way to do it, but you can add or modify the logo style on the responsive.css that you can find on the following path:
templatesjf_creativiacss
At the beggining of the file you will see all the media queries:
@media (min-width: xxxxx) and (max-width: xxxxx)
You can change your style there. For example I modified the menu for the website
cacciagliaphotography.com you can have a look. Consider that I'm still working on it!