Keep category navigation menu visible when in a category page (mobile)

Site URL: http://www.graciavintage.com

On mobile, if you're in a category the only way to get to another category is to navigate all the way back to the main shop screen. I would love to be able to keep the category menu visible at the top of the screen after you click into a category. I've seen workarounds posted on here, but only ones that affect both desktop and mobile, and I'd like to keep my desktop navigation as it is.