The following documents outline how to customize Nanacast-hosted areas to control their look and feel via CSS:
Customizing Your Nanacast Embedded Form:
http://nanacast.com/docs/cssforms
Customizing Your Nanacast Secure Checkout Page:
http://nanacast.com/docs/csscheckout
Customizing Your Nanacast-hosted Thank You Page:
http://nanacast.com/docs/cssthankyou
Customizing Nanacast Membership Login Pages:
http://nanacast.com/docs/cssmemlogin
Customizing Nanacast Membership Content Pages:
http://nanacast.com/docs/cssmempage
Note: If the code examples in the above article are above your skill level in HTML/CSS/JavaScript, we strongly recommend you hire a developer to accomplish the customization you are seeking.