Highcharts.getJSON(
    'https://cdn.jsdelivr.net/gh/highcharts/highcharts@v7.0.0/samples/data/usdeur.json',
    data => {
        let detailChart;

        // create the detail chart
        function createDetail(masterChart) {
            // prepare the detail chart
            var detailData = [],
                detailStart = data[0][0];

            masterChart.series[0].data.forEach(point => {
                if (point.x >= detailStart) {
                    detailData.push(point.y);
                }
            });

            // create a detail chart referenced by a global variable
            detailChart = Highcharts.chart('detail-container', {
                chart: {
                    marginBottom: 120,
                    reflow: false,
                    marginLeft: 50,
                    marginRight: 20,
                    style: {
                        position: 'absolute'
                    }
                },
                credits: {
                    enabled: false
                },
                title: {
                    text: 'Historical USD to EUR Exchange Rate',
                    align: 'left'
                },
                subtitle: {
                    text: 'Select an area by dragging across the lower chart',
                    align: 'left'
                },
                xAxis: {
                    type: 'datetime'
                },
                yAxis: {
                    title: {
                        text: null
                    },
                    maxZoom: 0.1
                },
                tooltip: {
                    formatter: function () {
                        var point = this.points[0];
                        return '<b>' + point.series.name + '</b><br/>' + Highcharts.dateFormat('%A %B %e %Y', this.x) + ':<br/>' +
                            '1 USD = ' + Highcharts.numberFormat(point.y, 2) + ' EUR';
                    },
                    shared: true
                },
                legend: {
                    enabled: false
                },
                plotOptions: {
                    series: {
                        marker: {
                            enabled: false,
                            states: {
                                hover: {
                                    enabled: true,
                                    radius: 3
                                }
                            }
                        }
                    }
                },
                series: [{
                    name: 'USD to EUR',
                    pointStart: detailStart,
                    pointInterval: 24 * 3600 * 1000,
                    data: detailData
                }],

                exporting: {
                    enabled: false
                }

            }); // return chart
        }

        // create the master chart
        function createMaster() {
            Highcharts.chart('master-container', {
                chart: {
                    reflow: false,
                    borderWidth: 0,
                    backgroundColor: null,
                    marginLeft: 50,
                    marginRight: 20,
                    zoomType: 'x',
                    events: {

                        // listen to the selection event on the master chart to update the
                        // extremes of the detail chart
                        selection: function (event) {
                            var extremesObject = event.xAxis[0],
                                min = extremesObject.min,
                                max = extremesObject.max,
                                detailData = [],
                                xAxis = this.xAxis[0];

                            // reverse engineer the last part of the data
                            this.series[0].data.forEach(point => {
                                if (point.x > min && point.x < max) {
                                    detailData.push([point.x, point.y]);
                                }
                            });

                            // move the plot bands to reflect the new detail span
                            xAxis.removePlotBand('mask-before');
                            xAxis.addPlotBand({
                                id: 'mask-before',
                                from: data[0][0],
                                to: min,
                                color: 'rgba(0, 0, 0, 0.2)'
                            });

                            xAxis.removePlotBand('mask-after');
                            xAxis.addPlotBand({
                                id: 'mask-after',
                                from: max,
                                to: data[data.length - 1][0],
                                color: 'rgba(0, 0, 0, 0.2)'
                            });


                            detailChart.series[0].setData(detailData);

                            return false;
                        }
                    }
                },
                title: {
                    text: null
                },
                accessibility: {
                    enabled: false
                },
                xAxis: {
                    type: 'datetime',
                    showLastTickLabel: true,
                    maxZoom: 14 * 24 * 3600000, // fourteen days
                    plotBands: [{
                        id: 'mask-before',
                        from: data[0][0],
                        to: data[data.length - 1][0],
                        color: 'rgba(0, 0, 0, 0.2)'
                    }],
                    title: {
                        text: null
                    }
                },
                yAxis: {
                    gridLineWidth: 0,
                    labels: {
                        enabled: false
                    },
                    title: {
                        text: null
                    },
                    min: 0.6,
                    showFirstLabel: false
                },
                tooltip: {
                    formatter: function () {
                        return false;
                    }
                },
                legend: {
                    enabled: false
                },
                credits: {
                    enabled: false
                },
                plotOptions: {
                    series: {
                        fillColor: {
                            linearGradient: [0, 0, 0, 70],
                            stops: [
                                [0, Highcharts.getOptions().colors[0]],
                                [1, 'rgba(255,255,255,0)']
                            ]
                        },
                        lineWidth: 1,
                        marker: {
                            enabled: false
                        },
                        shadow: false,
                        states: {
                            hover: {
                                lineWidth: 1
                            }
                        },
                        enableMouseTracking: false
                    }
                },

                series: [{
                    type: 'area',
                    name: 'USD to EUR',
                    pointInterval: 24 * 3600 * 1000,
                    pointStart: data[0][0],
                    data: data
                }],

                exporting: {
                    enabled: false
                }

            }, masterChart => {
                createDetail(masterChart);
            }); // return chart instance
        }

        // make the container smaller and add a second container for the master chart
        const container = document.getElementById('container');
        container.style.position = 'relative';
        container.innerHTML += '<div id="detail-container"></div><div id="master-container"></div>';

        // create master and in its callback, create the detail chart
        createMaster();
    }
);
