Highchart 3d: Chart graph. Zaxis alignment issue

Question

I am working on a 3d scatter plot chart. But facing issues with setting up the position of z axis label. Kindly help me in getting it back in proper position. Thanks in advance.

I tried to play around with the zaxis values but no luck.

zAxis: {

  min: 0,
  max: 11,
  gridLineColor: 'white',
  categories: ['W', '1', '2', '3c', '3b', '3a', '4c', '4b', '4a', '5c', '5b', '5a'],
  labels: {
    y: 1,
    rotation: 30,
    align: 'center'
  }
}

JS Fiddle link : http://jsfiddle.net/suprcool01/xvdcqbyk/24/