I trying to edit the mobile menu in my store. When I looking at your demo store (pavilion), the mobile menu is centered in a nice way. The mobile menu in my store is placed to the left as default with closing x in the upper right corner.
How can set up the mobile menu like the one you have in your shop?
Off topic: I wish you can update your demo shop a little bit. It´s always nice to go inside admin area and take a look at the current settings, but it´s a lot of settings I can not find because it´s disabled, removed or invisible in your demo shop.
We cannot see your website, but assume you are using the latest version of Pavilion (2.x). From version 2 mobile menu is styled the way you describe menu on a white background and the close button at the top right corner. Everything is done in favor of flexibility – newer Pavilion menu is configurable and you can insert different header elements inside. More information can be found here: