Use CSS Class in HighCharts

Question

Instead of specifying CSS styles with highchart options such as (fontWeight, fontColor, etc), is it possible to use CSS classes for styling the different elements of a chart?

Answer 1

In many cases (tooltip,labels) you can set useHTML as true, and then use CSS styles without !important or use formatter to define your own elements with CSS styles.

Example http://api.highcharts.com/highcharts#tooltip.useHTML

Answer 2

Yes, you have to use !Important because it's the only way to override inline style.
Your chart is render on some content which you have to pass it's id on chart.rendertTooption.
So you can match the elements by your chart container, like.

#container text {
    font-size: 14px !Important;
}

Demo