Please critique my Game of Life!

Hey everyone! So I finished my Game of Life - https://codepen.io/Bosa100/full/LLVLJW. I’m pretty happy with it for the most part. One thing I wonder about is whether my use of react was decent. I actually kept some of the data outside of my React classes, and was wondering if it’s a good idea to mix React with straight forward Javascript in this way. Thanks for giving me a read! :smiley: