How to create Skins for Version 4

Hi,



We are a developer company and have never worked with CS-Cart. We are curious to see if it is an eCommerce option we can offer our clients.



I wanted to know where I can find information on creating my own skins for version 4. To ask it another way, after I design a website, what do I need to do to create a skin/theme that reflects my new design and that will work with version 4?



I just want to take my design, create a template and upload it to the cart and have it work. I am sure there is a lot to it and I am just taking it down to the basics.



I have looked around and have not been able to find anything.



Thanks for the help.



Stan