How to develop a website and an application for VK at the same time?

Question

Web development

In general, I am doing some kind of visual thing on which objects will move ...
For ease of understanding - imagine for a second that you are making a layout of the movement of the planets in HTML / CSS / JS, valid in the solar system in 2d format, i.e. in the middle the sun on a black background - planets fly around and stars shine, just like that. A simple page with not very complex animation...
The next question is on the site, i.e. on the Internet, it will not be a problem to implement using HTML5 / CSS / JS ... but there is a great desire to roll out the same thing into VK applications, or at least use most of the developments from the site there. The project's API itself is separate, work with it goes through the socket. I am inclined to the version that there will be just an iframe from the site, or is it not done like that? Maybe someone had such experience - development for both the site and VK at the same time?
Maybe someone will advise what GUI frameworks, or at least advise something.
Interested in a simple animation for the site and then roll out the same to VKontakte.
The question is what is the best way to do such things in order to do it at the same time "both as a site" and as a project that will work as a VK application (for the site www.vk.com - not for the mobile version).

Answer 1

They do it. I have a page on a site with interactive SVG and what is displayed in the application frame is generally the same code. The only difference is that instead of site users, you have to focus on VK users.