I'm trying to modify a custom thesis-setting class to my needs. It contains commands for setting odd, even and top margins, but I need a particular size (25mm) of the bottom margin as well. I did expect it to be the most elementary feature of LaTeX, but commands such as
\bmargin lead to crashes of my document. Research on the internet showed, that the bottom margin is not even there on the command-explaining diagram (example: https://www.sharelatex.com/learn/Page_size_and_margins).
So my question is: How do I set a fixed bottom margin size within a class?