Anticipating Transfer Dev Site to Live Site

Hello.

I am developing this site on my test site: martcol.co.uk/brightontherapyservice. I have a one page site now on the live site.

The more I get in to styling my theme I realise that I am depending on WP generated classes, especially in the navigation.

Now I am worried about transfering to the live site when I am ready?

Am I going to have to plan to hard code those generated classes again or is there a way that I can transfer the site with this in mind?

Thanks

Martin