Porfolio pages with different styles

I'm trying to create multiple portfolio pages on the same website which use different settings/ styles.
For example, I'd like them all to be a 'simple grid', but I want one to be 3 columns with an aspect ratio as Ultra Widescreen, and another to have 4 columns with aspect ratio of 3;2....

When I update the settings of one it updates these across both portfolios. Is it possible to style these separately?

ULTRA WINDSCREEN https://maroon-sponge-lp55.squarespace.com/portfolio-2-2-1

3:2 ASPECT https://maroon-sponge-lp55.squarespace.com/commissions

I plan on having multiple portfolios and id love them to al be different styles. 

Any help would be great... 

Jack 

Add to Design > Custom CSS

/* Film page */
body#collection-637ddc379a040b50cd339bcf .grid-image {
    padding-bottom: 41.666% !important;
}

Champion, thankyou so much. Worked perfectly 

Jack