Highcharts 设置坐标轴文字样式

http://www.hcharts.cn/api/index.php#yAxis.labels.style

yAxis: {
	            title: {
	                text: ''
	            },
	            min:0,	            
	            gridLineWidth:'0px', 
	            plotLines: [{
	                value: 0,
	                width: 1,
	                color: '#fff'
	            }],
	            labels: {
	            	formatter: function () {
                    	return this.value
                	},
	                style: {
						color: '#fff',
						fontSize:'16px',
						fontFamily:'微软雅黑'
					}
	            },	           
	            lineWidth: 1
	        },