E_layout
{ flex:1 1 300px }
D_layout
{ flex:100 1 300px }
C_layout
{ flex:0 0 300px }
D_layout
{ flex:1 1 300px }
B_layout
{ max-width:60rem; margin:auto }
A_layout
{ margin:10% }
DEFAULT_layout
{ full-width, auto-height, no-margin }
FULL_layout
{ absolute-full }
FLOAT_layout
{ absolute-float }