Particle system extends across entire page

[benslv]

Describe the bug
Since updating this project's dependencies, the particle system shown at the top of the page now extends to fill the entire height of the index page.

To Reproduce
Steps to reproduce the behavior:

1. Visit the website
2. Observe that the error is there, with your eyes.

Expected behavior
The particles should be contained within the header section of the website, and the rest of the website should have a plain, grey background. The particles should also scroll with the rest of the page, rather than sitting static in comparison to every other element.

Screenshots

Additional context
Sorry about this. I did a full upgrade of all dependencies a few days ago - both Gatsby and React have released very major changes since we last properly touched the site - and I think an update in the react-tsparticles package may have caused it to start acting differently.