Resizing image on footer on mobile to appear larger

Hello,

I need help putting code to resize an image on mobile to appear larger. 

The site is https://www.nyumbai.com/ and it's the image on the right on the footer. 

The format looks fine on desktop but once in mobile, the image appears small and not the full width to the mobile screen that'd I want. 

Thanks in advance!

Add to Home > Design > Custom CSS

@media screen and (max-width:640px) {
div#block-yui_3_17_2_1_1572209846063_7829 img {
    width: 100% !important;
}
}

It worked! Thanks a bunch!