How to randomize animation in Sass/SCSS mixin?

Question

css

There is such an effect - https://codepen.io/kodekrendel/pen/pPQeBa
The problem is that I can't figure out how to randomize it somehow? Introduce some random variable, or at least make it not so noticeable to the eye that the effect repeats every 2 seconds? Very eye catching.

Answer 1

Seriously, Sass gurus, where are you? What can you think of here?