Working out the unique parent element ID

I am trying to work out how to use the unique parent element ID but not sure what it is. I assumed it is the field ID in the form but this is not working.

Could you please explain this in detail. My form is ID 7 and my Field id is 2. How can I make the below work for this please.

body .gform_wrapper_ 1 .gform_body .gform_fields #field_XX_X.gfield .ginput_container_website input { border : 1px solid red ;}

Can you share a link to the page on your site where we can see the form? Also, what is your end goal? Thank you.