.applet {
  background-color: #eeeee0;
  border-radius: 5px;
  box-shadow: 1px 1px 2px gray;
  display: grid;
  grid-template-columns: auto;
  grid-template-rows: 256px;
  margin: 0 auto;
  width: 256px;
}

@media screen and (min-width: 640px) {
  .applet {
    background-color: #eeeee0;
    border-radius: 5px;
    box-shadow: 1px 1px 2px gray;
    display: grid;
    grid-template-columns: auto;
    grid-template-rows: 512px;
    margin: 0 auto;
    width: 512px;
  }
}

.applet div {
  text-align: center;
}

#canvas_div {
  width: 100%;
  height: 100%;
}

canvas {
  width: 100%;
  height: 100%;
  touch-action: none;
}