< align opposite axis to start (at the back)
> left to right (at the front) and/or align opposite axis to
end (at the back)
| anchor (at the front and/or back)
! sticky (at the front and/or at the back)
/ even space (at the front)
% center in split space (at the front)
+ stretch (for all at the front and/or per selector and/or opposite
axis at the back)