JFreeChart Remove Border From Chart

I am using JFreeChart with JavaFX and I have my chart looking almost exactly how I want. The last piece is this little bit of border that is still around the chart. I can't seem to figure out how to make the chart flush with the window pane.

Most answers that I've found so far have involved just setting the padding or opaque insets to 0, but that doesn't seem to fully solve the issue. I'm also not sure if this has something to do with ChartViewer adding some extra padding.

This is my code thus far.

public class TestApp extends Application
{

    public static void main(String[] args)
    {
        launch(args);
    }

    @Override
    public void start(Stage primaryStage)
    {
        TimeSeries throttleSeries = new TimeSeries("");
        throttleSeries.setMaximumItemCount(200);

        long currentTime = System.currentTimeMillis();
        for (int i = 200; i > 0; i--)
        {
            long now = currentTime - (i * 33L);
            throttleSeries.add(new FixedMillisecond(new Date(now)), 0.0);
        }

        TimeSeriesCollection timeSeriesCollection = new TimeSeriesCollection();
        timeSeriesCollection.addSeries(throttleSeries);

        Color throttleColor = Color.GREEN;

        XYLineAndShapeRenderer lineRenderer = new XYLineAndShapeRenderer();
        lineRenderer.setDefaultShapesVisible(false);
        lineRenderer.setSeriesStroke(0, new BasicStroke(2f));
        lineRenderer.setSeriesPaint(0, throttleColor);

        XYAreaRenderer areaRenderer = new XYAreaRenderer();
        areaRenderer.setSeriesVisible(0, true);
        areaRenderer.setSeriesPaint(0, throttleColor);

        var areaChart = ChartFactory.createTimeSeriesChart("", "", "", timeSeriesCollection, false, false, false);
        var lineChart = ChartFactory.createTimeSeriesChart("", "", "", timeSeriesCollection, false, false, false);

        setJFreeChartStyle(lineChart);
        lineChart.getXYPlot().setRenderer(lineRenderer);

        setJFreeChartStyle(areaChart);
        areaChart.getXYPlot().setRenderer(areaRenderer);

        StackPane stackPane = new StackPane();
        stackPane.setStyle("-fx-background-color: black;");

        ChartViewer bottomChart = new ChartViewer(areaChart);
        bottomChart.setOpacity(0.3);
        bottomChart.setPadding(Insets.EMPTY);
        bottomChart.setOpaqueInsets(Insets.EMPTY);
        bottomChart.setBorder(Border.EMPTY);
        bottomChart.setStyle("-fx-background-color: transparent;");

        stackPane.getChildren().add(bottomChart);
        StackPane.setAlignment(bottomChart, Pos.CENTER);

        ChartViewer topChart = new ChartViewer(lineChart);
        topChart.setPadding(Insets.EMPTY);
        topChart.setOpaqueInsets(Insets.EMPTY);
        topChart.setBorder(Border.EMPTY);
        topChart.setStyle("-fx-background-color: transparent;");

        stackPane.getChildren().add(topChart);
        StackPane.setAlignment(topChart, Pos.CENTER);

        Scene scene = new Scene(stackPane, 400, 150);
        primaryStage.setScene(scene);
        primaryStage.show();

        Thread thread = new Thread(() -> {

            int counter = 0;
            while (true)
            {
                try
                {
                    Thread.sleep(33);
                }
                catch (InterruptedException ignored)
                {
                }

                int finalCounter = counter;
                Platform.runLater(() -> throttleSeries.addOrUpdate(new FixedMillisecond(),
                                                                   Math.sin(2 * Math.PI * 0.25 * (finalCounter * 0.033)) *
                                                                   0.5 +
                                                                   0.5));

                counter++;
            }
        });

        thread.setDaemon(true);
        thread.start();
    }

    protected void setJFreeChartStyle(JFreeChart chart)
    {
        chart.setBackgroundPaint(new java.awt.Color(0, 0, 0, 0));
        chart.setBorderVisible(false);
        chart.getXYPlot().getRangeAxis().setRange(0, 1);
        chart.getXYPlot().setOutlineVisible(false);

        chart.getXYPlot().getDomainAxis().setLowerMargin(0.0);
        chart.getXYPlot().getDomainAxis().setUpperMargin(0.0);
        chart.setPadding(RectangleInsets.ZERO_INSETS);
        chart.getXYPlot().setBackgroundAlpha(0);
        chart.getXYPlot().setInsets(RectangleInsets.ZERO_INSETS);

        chart.getXYPlot().setRangeCrosshairVisible(false);
        chart.getXYPlot().setRangeZeroBaselineVisible(false);
        chart.getXYPlot().setRangeGridlinesVisible(false);
        chart.getXYPlot().setRangeMinorGridlinesVisible(false);

        chart.getXYPlot().setDomainCrosshairVisible(false);
        chart.getXYPlot().setDomainZeroBaselineVisible(false);
        chart.getXYPlot().setDomainGridlinesVisible(false);
        chart.getXYPlot().setDomainMinorGridlinesVisible(false);

        chart.getXYPlot().getDomainAxis().setVisible(false);
        chart.getXYPlot().getRangeAxis().setVisible(false);
    }

As shown here for an XYPlot and here for a CategoryPlot, you can remove the plot's axis offset like this:

var plot = chart.getXYPlot();
plot.setAxisOffset(RectangleInsets.ZERO_INSETS);