How to rotate x-axis labels in chart?

Hi,

I am trying to rotate the x-axis labels in the chart using the following code in CSS-class chartsytle without success.

chartstyle g.v-m-xAxis g.v-label {

    -webkit-transform: rotate(-20deg);

    -moz-transform: rotate(-20deg);

    -ms-transform: rotate(-20deg);

    -o-transform: rotate(-20deg);

    transform: rotate(-20deg);

}

How to make it works?

Thanks.

Best regards,

Zabrina