E-commerce Web design

I wanted to create an e-commerce website with a clean checkout process that is easy to complete.
Imagine you have entered a category page, scrolled around, set your filter to only show specific products in a specific price point. You see that awesome product, click on it and now you have totally left the previous page. I don't know, maybe it's just me but I would like to preview that product, make a decision and get on with my life.

The solution I came up with was a smaller product page, in a modal format, to enable the user to never have to leave the page they are on.
They can go through the entire purchase - pick a product, choose size and variants, add more products and complete the checkout. Also, this way, as the customer doesn't leave the category page, they are presented with more products after their purchase. Making them more eligible to buy more.

All images of clothing are from various clothing companies like - NLY MAN, Stayhard, H&M, Care of Carl.