案件回访(1890)echarts 饼配置项内容和展示

请问文字怎么自适应？我只想显示‘’回访‘’与‘未回访’的 导线怎么实现

      var cb=0.7,ncb=0.3;

option = {
        title: {
            text: '案件回访(1890)',
            left: '7%',
            top:'3%',
            textStyle: {
                fontFamily: "SourceHanSansCN Light ",
                fontSize: 18,
                fontWeight: 400
            },

        },
        calculable : false,
        legend: {
            orient: 'vertical',
            data:['回访','未回访'],
         
            right: '5%',
            top: "20%",
        },
        series : [
            {
                name:'比例',
                type:'pie',
                center : ['50%', '50%'],
                radius : ['30%', '40%'],
                itemStyle : {
                    normal : {
                        label : {
                            show : false
                        },
                        labelLine : {
                            show : false
                        }
                    }
                },
                color: ['#baf215','#1c262f'],
                label: {
                    normal: {
                        show: true,
                        position: 'center',
                        formatter: '未回访:567'
                    },

                },
                data:[
                    {value:ncb, name:'未回访'},
                    {value:(1-ncb), name:''}
                ]
            },
            {
                name:'比例',
                type:'pie',
                color: ['#12d7e4','#1c262f'],
                center : ['50%', '50%'],
                radius : ['50%', '60%'],
                itemStyle : {
                    normal : {
                        label : {
                            show : false
                        },
                        labelLine : {
                            show : false
                        }
                    }
                },
                label: {
                    normal: {
                        show: true,
                        position: 'outside',
                        formatter: '回访:1323',
                        textStyle:{
                            fontSize:14
                        }
                    },

                },
                labelLine: {
                    normal: {
                        show: true,
                        length: 10,
                        length2: 12,
                        lineStyle: {
                            width: 2
                        }
                    }
                },
                data:[
                    {value:cb, name:'回访'},
                    {value:(1-cb), name:''}
                ]
            },

        ]


    };