If you want to change blog page layout to this on Squarespace.
You can use this code to Custom CSS box.
/* Blog Page layout */
.blog-basic-grid .blog-basic-grid--container:first-child {
grid-column: ~"1 / 3";
}
If you want to apply this for a specific blog page, you can find the Blog Page ID.
In my example, we will have:
- #collection-6677756d03a4f15ba27ce9d8
Next, use this CSS code
#collection-6677756d03a4f15ba27ce9d8 .blog-basic-grid--container:first-child {
grid-column: ~"1 / 3";
}