CSS for making portfolio pages with different aspect ratios

Hi,

I am looking to make the aspect ratios of one portfolio page different to another. Specifically, I would like the "Personal" page (which is at 2:3 at the moment) to be at the 16:9 aspect ratio, while keeping the "Commissions" page at the 2:3 ratio. Please advise on how this can be done? Thank you in advance. 

You could consider using Image Galleries (that are far more flexible even without additional CSS coding) and link the images manually to the related project

Thank you for the code, it worked after I put the code on the advanced settings of the "Personal" page.