Help with Venture Theme (Collection list products numbers & sizes)

Hello, I am slowly redesigning my shop based on the Venture theme, but I do have a little bit of a hustle regarding my homepage collection list. I would like the .product-card on each collection to be smaller in height, then be able to show around 6/7 products per rows, and maybe 4 rows in total. Sadly on the venture theme you can only go up to 4 rows and you cannot change the number of columns. They take so much space, and I do have a lot of products, so I would like to make the whole thing smaller.
Is there anything I can add to the section code to show the option, or can I just change it through the CSS ?
Shop address is https://sfx-eyes.jp

Thank you !!!