I'm glad it helped! I'll try and implement the dark mode in 1.6.0. I've recently just been trying to get it more consistent, so I've been putting off making it look nicer for a while. I'm not sure what you mean by the "+" key, but I'll look into it

https://imgur.com/a/gsH87Qi

I tested using [ and ] and it seems fine?

Also, if you'd like to keep up with the code, or post issues and feature requests, the repository is at: https://github.com/SoPat712/videospeed