How to reduce the size of an image within a mobile footer on 7.1

Site URL: https://sprout-alpaca-92j6.squarespace.com/

Hey folks! I added my client's logo to her footer. It looks great on desktop, but on mobile it converts to the full width of the screen. We want the logo image to be smaller on mobile. Is there a way I can do this in CSS? I have tried targeting the padding with no luck.

My backup is creating a custom PNG with more padding, but I don't love that option for various screen sizes.

Can someone help me out? 

Site password: kenshosalon

@Nabiloh amazing. That works great—thank you so much!