code make the tooltip shape like this
this is what i tried but no luck
tooltip: {
outside: true,
useHTML: true,
style :{
borderRadius: "10px 10px 10px"
},
pointFormatter: customPointFormatter
}
});
You can enable the useHTML option and style the tooltip by CSS:
.highcharts-tooltip > span {
padding: 10px;
border: 2px solid red;
border-radius: 30px 30px 30px 0;
}
Live demo: http://jsfiddle.net/BlackLabel/wver5hyf/
About border radius: https://www.w3schools.com/cssref/css3_pr_border-radius.asp