echarts_渲染出的图表和文字模糊问题

方法1：使用svg渲染，svg渲染出的图表的清晰度高于canvas

var myChart = echarts.init(document.getElementById('chart'), null, {renderer: 'svg'});

https://www.echartsjs.com/zh/tutorial.html#%E4%BD%BF%E7%94%A8%20Canvas%20%E6%88%96%E8%80%85%20SVG%20%E6%B8%B2%E6%9F%93
方法2：仍然使用canvas渲染，通过调整devicePixelRatio提升清晰度

var myChart = echarts.init(document.getElementById('chart'), null, {devicePixelRatio: 2.5});

https://github.com/apache/incubator-echarts/issues/6054