This is a great use case for prismic.io!

Since all of your content is structured and delivered through your API, you can simply pull it from your application, and use the content the way you want. Look at me take an existing Bootstrap site, and inject content in it: https://blog.prismic.io/Ux-CMgEAAFwI9kFg/turn-a-bootstrap-th... (here in PHP, but you can use any technology you want). Here, it's a static Bootstrap site, but if your application was more complex, it wouldn't me more complicated to embed prismic.io powered content!