.chart {
         width: 500px;
         height: 500px;
        }
        
#loading-indicator {
  position: absolute;
  left: 50%;
  right: 50%;
  top: 50%;
  bottom: 50%;
  width: 100px;
  height: 100px;
  margin-left: -32px;
  margin-top: -32px;
  border: 0;
}
