Different Banner Image on Mobile

Hello! So my site is  https://earthlycraft.co/

It's almost there... but i cant work one thing out. How to change one of my banner hero images for mobile. It looks great on desktop however its too small on mobile,  so i have another logo ready thats zoomed right in that i'd like to use for mobile only. I've added the file in design > custom css > manage custom files so i can use the link to the file

I'm fairly familiar with media queries but i don't know the code to change the banner. When I inspect I get this code:

.sqs-block-image .image-block-outer-wrapper:not(.image-block-v2) .intrinsic .image-block-wrapper img

Therefore i'm going for something along the lines of:

@media only screen and (max-width: 600px) {.sqs-block-image .image-block-outer-wrapper:not(.image-block-v2) .intrinsic .image-block-wrapper img {background image: https://static1.squarespace.com/static/5d00032088447c0001487495/t/5dcdc90c40062f0cf29e9ddc/1573767446853/mobilelogo.png;}}

Help would be much appreciated!!

Cheers!!