TileMill .302 carto nested style questions

nested_styles

*********** works, but super repetitive, unweildy:

#admin0[zoom=3][ADM0_A3='USA'] {
  polygon-fill: @yellow; }

#inner1[zoom=3][ADM0_A3='USA'] {
  polygon-fill: #f66;  
  polygon-opacity: .6; }

#ad0borders[zoom=3][ADM0_A3='USA'] {
  line-width: 1;
  line-color: #888;}



*********** doesn't work:

[zoom=3][ADM0_A3='USA'] {
 
#admin0 {
  polygon-fill: @yellow; }

#inner1 {
  polygon-fill: #f66;  
  polygon-opacity: .6; }

#ad0borders {
  line-width: 1;
  line-color: #888;}
}