I like swagger for documenting Restful APIs very much, especially \"Try it out!\" button, but swagger-ui
interface doesn\'t look very cool.
And I cannot bel
Swagger-UI, while not being a new tool, is very specific for its task. I'm unaware of any website the provides themes for it (free or paid). Many of its users have customized the UI to fit their local theme. Some have made subtle changes, some a complete overhaul.
I'd recommend looking around at the available implementations and see if something suits your needs. Then perhaps ask permission to reuse their theme/template for your own needs.