* {
  padding: 0;
  margin: 0;
  box-sizing: border-box; }

.wrapper {
  /* because canvas has position: absolute by default */
  position: relative;
  /* so that canvas is responsive */
  touch-action: pan-y pinch-zoom;
  /* so that canvas is responsive - overflow-x
    only works in mobile if set both on canvas
    and its wrapper 
    */
  overflow-x: hidden; }

#canvas {
  margin: 1.5rem auto 0;
  display: flex;
  justify-content: center;
  background: #cf1e92;
  width: 90%;
  max-width: 600px;
  /* so that canvas is responsive - overflow-x
    only works in mobile if set both on canvas
    and its wrapper 
    */
  overflow-x: hidden; }