Bigcommerce CSS Expert To Urgently Fix Cart - More Work For Successful Contractor

We have discovered a big problem with our cart where the cart items section is not collapsing properly and hence not allowing visitors to see the checkout price, etc. Need an expert in responsive design, preferably with Bigcommerce experience. We can point you to exact location of problem, we just need your expertise to fix it. You can see in the screen shot attached, I have shown how it looks on desktop which is fine, but then the problems when reduced to mobile - that the Grand totals areas all down the bottom are obscured, so mobile users can not see them. The winning contractor will need to explain where the problem was, and what lines of code they adjusted to fix it for our records.