How can I make the mobile blog thumbnail image smaller? (Using CSS)

Site URL: https://curiositychina.squarespace.com/

How can I make only the mobile blog thumbnail image smaller using CSS coding?

Making this image smaller

Add the following to Design > Custom CSS.

@media screen and ( max-width: 767px ) {

  #collection-60069e0f71e85811ae7b79df .blog-side-by-side .blog-image-wrapper {
  
    width : 50%;
    
    }
  }

This is for a v7.1 site.

Let us know how it goes.