Custom Made Stairs For Bunk Or Loft Bed (CT)

What is the step height of each step? And then what is the height at the top of the highest step? It seems that the 55in H figure includes the height of the siderails/backrail above the steps? Also, if I do not require the backrails to extend above the top step is that possible? I need to use this with a 49in high platform bed, but I have limited space for the steps so I want them to stow under the platform by a few inches - and this would require only one side rail (the left side when facing) to protrude above the top step. Any diagrams you have of the different configuration options would also be helpful. Thanks!