echarts字体适配

var html = document.getelementsbytagname("html")[0];
var width = html.clientwidth;
var tooltipfontsize = 14 / 1280 * width;
var fontsize = 10 / 1280 * width;
var legendfontsize = 10 / 1280 * width;
var labelfontsize = 10 / 1280 * width;
var itemheight = 8 / 1280 * width;
var itemwidth = 10 / 1280 * width;