Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.3.8)
// Compass (v1.0.0.alpha.19)
// ----

$z-layers: (
  "goku":            9001, 
  "shoryuken":       8000,
  "modal": (
    "base":           500,
    "close":          100,
    "header":          50,
    "footer":          10
  ),
  "default":            1,
  "below":             -1,
  "bottomless-pit": -9000
);



@function map-has-nested-keys($map, $keys...) {
  @each $key in $keys {
    @if not map-has-key($map, $key) {
      @return false;
    }
    $map: map-get($map, $key);
  }
  
  @return true;
}

@function map-deep-get($map, $keys...) {
  @each $key in $keys {
    $map: map-get($map, $key);
  }
 
  @return $map;
}

@function z($layers...) {
  @if not map-has-nested-keys($z-layers, $layers...) {
    @warn "No layer found for `#{inspect($layers...)}` in $z-layers map. Property omitted.";
  }
 
  @return map-deep-get($z-layers, $layers...);
}

.modal {  
  position: absolute;
  z-index: z("modal", "base");
 
  .close-button {
    z-index: z("modal", "close");
  }
 
  header {
    z-index: z("modal", "header");
  }
 
  footer {
    z-index: z("modal", "footer");
  }
}
.goku {
  z-index: z("goku");
}

SassMeister-output.css

.modal {
  position: absolute;
  z-index: 500;
}
.modal .close-button {
  z-index: 100;
}
.modal header {
  z-index: 50;
}
.modal footer {
  z-index: 10;
}

.goku {
  z-index: 9001;
}