The explanation of fr is easy to misinterpret. Specifically this statement:
the first element occupies 1/4 and the second element 3/4 of any leftover space.
This leads me to believe that the first element will take up 1/4 of the available space and the second element will take up 9/16 of the available space (3/4 of the remaining 3/4).
https://github.com/thomaspark/gridgarden/blob/e11f74c8511c757ae418896c919e333cfa1030b8/js/levels.js#L1067
The explanation of fr is easy to misinterpret. Specifically this statement:
This leads me to believe that the first element will take up 1/4 of the available space and the second element will take up 9/16 of the available space (3/4 of the remaining 3/4).