In this link, the section [Vertical Stack - Gap and Padding Sizes], click [Show code], then at lines 30, 34, 38, etc. I see some strange values of padding (and some of childrenGap) like 'm 40px', 's1', 's2', 'l1', and have no idea what they mean or where they are defined.
I tried to play around its code and not sure where to go next after the line 9 in this file.
Could someone please point me to their definition or document?
Thank you.