phone_app/app/assets/stylesheets/3-components/_chart.scss

.chart {
  margin: auto;
  position: relative;
  width: 100%;
  min-height: 300px;

  &-xs {
    min-height: 200px;
  }

  &-sm {
    min-height: 250px;
  }

  &-lg {
    min-height: 350px;
  }

  canvas {
    max-width: 100%;
  }
}