.highcharts-label-box {
    stroke: #ccc;
    stroke-width: 1;
}

.highcharts-navigator-xaxis.highcharts-axis-labels {
    font-size: 14px;
    opacity: 0.8;
}

.highcharts-label.highcharts-range-label text {
    font-size: 11px !important;
}