Onshape is a CAD program which is entirely online, and my favorite. Meaning you can use it from any computer anywhere. As I regularly change from using my home desktop, to laptop, to other desktops, it is super useful to not need to re-install it, or move the file via USB every time. I've used it to make a variety of things, mostly for high-school work, but some personally.
It works by having you create "sketches" on one plane, then extruding and manipulating solid objects from that "sketch." This is much more intuitive to me than something like SketchUp, where you use 2d faces rather than solid objects, or Blender, where you don't work with measurements.
It is also a procedural system, so you can alter anything that you have done to the model before, and it will attempt to reconcile that with all the following modifications. By attempt I mean, most of the time it gets it right, but occasionally you need to go back into a few steps and fix them. This is super useful for when you realize, halfway through making something, it would actually be better if it was half a cm shorter, or that you need to alter the shape fundamentally.
From this haiku I pulled 3 key phrases, some of which where more parts of each other than I'd like, but hey, it had a pretty clear theme:
Fear of the Dark The fear of the dark is a primal fear which most people have, or rather, people have fears of things, and the dark amplifies them. I listen to horror podcasts quite a bit, and one of the things that I remember them speaking about that really resonated with me is that we are not really afraid of the dark. We are afraid of what might be lurking just out of sight. Which leads me onto my second idea for a theme.
Fear of Things that You Don't Know There's always that fear, on a late night, or in a particularly lonely forest, that something is there. Just out of sight. You hear the echos of their footsteps behind you, you feel their eyes on your back, but when you turn, there's no-one there. It's the fear that someone, something, is stalking you, watching you, and you have no idea where it is. Darkness is a good amplifier for this, as it hides things. Is that someone standing at the end of your bed, or just your mind making patterns out of your laundry? Now this is slightly different from the fear of the dark, as it doesn't always involve things that we can't see. Just things we don't know. So this could appear in the middle of the day.
Isolation This idea of "lost souls" resonates with the idea of darkness to me in a sense of Isolation. The darkness is isolating, there could be someone out there, but there could just as well be no-one. And, what is a "lost soul" but someone who feels adrift, isolated even amongst people?