An SVG Line chart with a dark theme

A dark themed filled Line chart with a red tinge to it. The chart is using a gradient as the fill color and is also using the spline option. The background of the chart is dark by using the colorsBackground option.

This goes in the documents header:
<script src="../libraries/RGraph.svg.common.core.js" ></script>
<script src="../libraries/RGraph.svg.line.js" ></script>
Put this where you want the chart to show up:
<div style="width: 950px; height: 250px" id="chart-container"></div>
This is the code that generates the chart:
<script>
    var data = [4,5,3,8,6,5,9,4,1,8,5,6,8,9,4,8,7,9,8,9,11,13,10,12,11,16,15,18,13,19,21,17,19,23,18,21,25,26,24,29,30];

    var line = new RGraph.SVG.Line({
        id: 'chart-container',
        data: data,
        options: {
            colors: ['red'],
            linewidth: 5,
            backgroundGridColor: '#666',
            backgroundGridVlinesCount: 4,
            backgroundColor: 'black',
            xaxis: false,
            xaxisTickmarks:false,
            xaxisLabels: [
                'Quarter 1',
                'Quarter 2',
                'Quarter 3',
                'Quarter 4'
            ],
            xaxisLabelsPosition: 'section',
            yaxisTickmarks:false,
            yaxis: false,
            spline: true,
            filled: true,
            filledColors: ['Gradient(rgba(255,0,0,0.75):rgba(255,0,0,0.5):rgba(255,0,0,0))']
        }
    }).trace();
    
    line.svg.style.borderTopLeftRadius = '25px';
    line.svg.style.borderBottomRightRadius = '25px';
</script>