If you wish to register only the design template or the graphic elements, you can upload the registration file that contains the template along with the images and other components of the work. When making the registration, you can indicate the "Artistic" category for electronic and multimedia pages. If the development of the web also includes programming code, you can register the entire set as "Project - Software" or register the design and programming separately. 

Note: 

The choice of one category or another is not especially relevant, as the work is registered and deposited in any case, and this classification serves as a guide for search and query functionalities.
If you also want to register articles from a blog, or content that you publish on a website, we explain it here.