Hi @jonopoon,
Thank you for reaching out to us. Currently there are no responsive options to set padding/margins in different devices, you’ll need to do this with custom CSS, while that is outside the scope of support, I could point you in the right direction with the understanding that it would ultimately be your responsibility to take it from here.
You can achieve this using CSS media queries, here are some relevant threads that you can follow as a starting point Change Section Padding On Mobile and Decrease padding margin on small screens
Here are some related links for further reading, this could help you in finding and implementing some CSS fixes:
Hope this helps!