Add a Div to existing Workpress Site

Hi,

I have Wordpress website link It's using a custom theme 'nexus'.

I'd like to add a search option to the top of the site,  as the one on the sidebar is not very prominent. I'd like to have a search box here;


I know that that is a div called 'top-info' so I would need to put a div within that, I'd also need to make that div sit in the top right.

Question 1: I've looked though the wordpress theme editor and the only reference I can find to top-info is in the style.css, where is it being called from?

Question 2: I've installed the Relevanassi search plugin, this says it replaces the in-built Wordpress search, Am I to assume that the existing search (on the sidebar) is using this, and I can replicate that code into the new search option?

Regards,

Pete