heres the solution for styling cms pages by its ID:
point to a specific cms page with ".cms-17" and then to a class you need.
for example: .cms-17 .revealimg
at the end it should look like this:
.cms-17 .revealimg {
width: 100%;
}
same applies to product pages:
.product-17 .revealimg {
width: 100%;
}