How do I build a fluid form on a Unbounce landing page?

I need to build a fluid/rolling form where once one questions is answered it scrolls to the next - see example below.. something along these lines. 

https://theukdebtexpert.co.uk/calculator/ 

I don’t want to build it within a pop-up form, I want it to be directly located on the landing page. 

Have any built anything similar to this that could provide code for? 

Hoping to turn this around quite quickly. The landing page is already built so just need to add this in.