Collection ID's & Custom CSS When Transferring a Template

Hello, I'm creating a template that I'm going to be selling however as I'm testing it when I transfer it the custom css is lost for any #ids. I've used #collection and #block ids to tweak some elements (e.g the leaf graphics I've added a -10px margin). Is there anyway of transferring a duplicated site over and keeping the same collection IDs, or an alternative way of targeting id's that will transfer accross.

Site is: https://wild-wood.squarespace.com/

An example would be this strip should be flush with the top of the page and I've used CSS to do this https://wild-wood.squarespace.com/links . But in the copied site it's gone back to the middle as below:

3 minutes ago, CharlotteWilderness said:

Hello, I'm creating a template that I'm going to be selling however as I'm testing it when I transfer it the custom css is lost for any #ids. I've used #collection and #block ids to tweak some elements (e.g the leaf graphics I've added a -10px margin). Is there anyway of transferring a duplicated site over and keeping the same collection IDs, or an alternative way of targeting id's that will transfer accross.

Site is: https://wild-wood.squarespace.com/

An example would be this strip should be flush with the top of the page and I've used CSS to do this https://wild-wood.squarespace.com/links . But in the copied site it's gone back to the middle as below:

There is no option to keeping same ID. Those will be change. You need to put IDs manually for the new site on your CSS. 

Thankyou that makes sense I'll look into that!