Position Image In Absolute Position

[ Moderator note: moved to Fixing WordPress. ]

Hi!

I would like to post an image right under the secondary menu, to the right of the search element, on top of whatever is under it and hides with mobile.

Here’s my dev site: http://www.discountsalsashoes.com/dev/

I’m just a beginner in CSS so if anyone could help, I’d really appreciate the guidance.