There are certain aspects of it that look more complicated than they are because you are seeing it as a representation on a flat map. It makes a lot more sense when you see it on a globe with all the pieces moving in 3d space.

https://youtu.be/ujYYlXP12m4

It is complicated because there are tilts to the earths rotation and a tilt to the moon's orbit, but people thousands of years ago figured it out, so it's solvable.