We have a successful e-commerce website that was designed in 2009 and is non-responsive. We'd like our site to be converted to a responsive framework like Bootstrap so that it renders properly on mobile devices. The backend coding is done using ASP.NET MVC, and that doesn't need to change, just the front-end html. We use Bootstrap a bit on some of our administration pages and it has worked well, but we need help with the design of our home page, brand and category catalog pages, product detail page, cart, and checkout. Ideally, you would look at our site and provide new html and possibly replacement graphics that will work with a responsive framework.