Design a ladder -- 2

I am in need of a sturdy and reliable ladder that's designed for indoor use. Specifically, I need a ladder made of any reasonably attainable material(s) (i.e., wood is preferred, but plastic, 3D printed, metal, etc., is fine also) with a maximum height of less than 4 feet. I know there are a lot of ladders already in existence, but I need to create a ladder that's specific for my needs. Here are my specific needs (the hard part, and the reason why I can’t just buy an existing ladder): 3-4 planar steps (not a “rung” step, but 5-6 inches or more to allow more than the toes of my foot to step on); it needs to be able to collapse/close/fold into a space that is no bigger than 54” H x 16” W x 2” D; and I need it to have a top step height (when open) that gets me at least 2 1/2’ to 3’ above the ground. The final product should be able to support up to 250 pounds and ideally will have all necessary safety measures built into it. I don’t care if it is attractive, it just needs to be functional and fold into the size described above—it cannot be more than 2 inches deep at any point. Your input, expertise, and unique ideas are great. I have tried to come up with several designs, but but i simply don’t have the time to figure out all of the details. If you think you have the skills required to complete this project, I'd be more than happy to discuss the specifics with you. Thank you for your consideration.