Best technology/framework to use for a front-end project with complex animations


I am currently building a front-end project together with my girlfriend (she’s a UI/UX designer). It animates the origin of higher mass elements. I built it using HTML, Sass and jQuery + Greensock Animation Framework, but it looks terrible on different screen sizes (see the live site). I tried using the HTML5 Canvas + paper.js library, but that was even less successful.

Would anyone have any suggestions, ideas or relevant examples? Thanks a lot!
Source code of live site is here:
I made an attempt to make it more responsive in repo wdehaes/stars-project


Have you heard of Processing?

Check out P5Js.

And also "The Nature of Code"