[Theme: EvoLve] How to remove the search button from main menu bar

Hello,

I have been trying to remove the search (magnifying glass button) from my main menu bar. In the mobile version it is going underneath my menu and just makes the menu bar look huge and not very attractive.

I am using the free evolve theme and my site is cross-terrain.com

I have tried this CSS that I found in another forum but it did not work:

#masthead .icon-search {
display: none;
}