Stacking chips + zoom based styling

style.css

Map{
buffer-size:2048px;
}

@w: 8;
@h: 8;

#layer { 
  marker-fill: ramp([abv], (#f7f7f7, #cccccc, #969696, #636363, #252525), quantiles);
  marker-fill-opacity: 0.9;
  marker-line-color: #424141;
  marker-line-width: 0.6;
  marker-line-opacity: 1;
  marker-placement: point;
  marker-type: ellipse;
  marker-width: @w;
  marker-height: @h;
  marker-allow-overlap: true;
  marker-transform: translate(0, -2*([p]-1));
  
  [zoom > 3] {
    marker-width: @w+5;
    marker-height: @h+5;
  }
  
  [zoom > 5] {
    marker-width: @w+10;
    marker-height: @h+10;
  }
  
   [zoom > 7] {
    marker-width: @w+15;
    marker-height: @h+15;
  }
  
   [zoom > 9] {
    marker-width: @w+20;
    marker-height: @h+20;
  }
  
}