Remove the handheld navigation bar

I was researching how to do this and found this link: https://docs.woocommerce.com/document/remove-the-handheld-navigation-bar/.

I tried copying that supplied code into my Appearance>Customize>Additional CSS but it just gives me large red X’s next to it basically saying they are all “unexpected tokens”

what is the CSS that I can use to remove this?

The page I need help with: [log in to see the link]