SOURCE

option = {
  xAxis: {
    type: 'category',
    data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'],
    axisLine: {
      lineStyle: {
        color: '#ccc',
        opacity: 0.1
      }
    },
    axisLabel: {
      color: '#ccc'
    },
    splitLine: {
      show: true,
      lineStyle: {
        opacity: 0.9
      }
    },
    axisTick: {
      show: false
    }
  },
  yAxis: {
    type: 'value',
    axisLine: {
      lineStyle: {
        color: '#fff',
        opacity: 0.9
      }
    },
    axisLabel: {
      color: '#ccc'
    },
    nameLocation: 'middle',
    nameGap: 50,
    splitLine: {
      show: true,
      lineStyle: {
        opacity: 0.9
      }
    },
    axisTick: {
      show: false
    }
  },
  legend: {
    show: false,
    textStyle: {
      color: '#fff'
    }
  },
  grid: {
    top: 30
  },
  tooltip: {
    show: true,
    trigger: 'axis',
    axisPointer: {
      type: 'line'
    }
  },
  axisPointer: {
    label: {
      backgroundColor: 'transparent',
      color: '#fff'
    }
  },
  series: [{
    data: [820, 932, 901, 934, 1290, 1330, 1320],
    type: 'line',
    // lineStyle: {
    //   opacity: 1
    // }
  }]
};
var chart = echarts.init(document.getElementById('themeChart'))
chart.setOption(option)

<div id ="themeChart"></div>

#themeChart{
  height:100vh;
  width:100vw;
}