body {
  background-color: #f8f9fa;
}
.shape {
  cursor: move;
}

#canvas1 {
  width: 324px;
  height: auto;
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  border: 2px solid #000;
  background-color: #f0f0f0;
}
.chess-tile {
  box-sizing: border-box;
}
.highlight {
  outline: 2px solid yellow !important;
}
button {
  display: block;
  margin: 20px auto;
}