[Solved]-highcharts redraw and reflow not working-Highcharts

Just remove the width of the chart from

$('#container').highcharts({
  chart: {
      type: 'line',
      width: 300
  },

so that it is like this

$('#container').highcharts({
  chart: {
      type: 'line'
  },

and set the container width to 300 like this

#container {
   width: 300px;
}

then just resize the container div as you are already doing. the chart will resize according to the width of the container div.

hope this helps.