Particle Js on hover as full screen interactive background

Hi, 

can I know how do I set this as a full screen background on my html site?

[http://codepen.io/nikspatel/pen/aJGqpv](http://Codepen "https://codepen.io/nikspatel/pen/aJGqpv")

I tried to set its css as: position :fixed; z-index:-10;

It work fine once I enter the site but when I scroll down, its not working as it should be. The particle is not following the cursor anymore, once I scroll down more, the particle just go missing. I also tried to set it as an iframe background but its not working once I move my cursor thought a div.

This is something I am trying to do : reference site .

Can anyone help?

Appreciate it. Thanks