.piece {
  cursor: grab;
}
/* #board is absolutely positioned, so it is out of normal flow: anything placed
   after it in the markup would paint underneath the board rather than below it.
   Pinning the credits to the bottom of the viewport keeps them out of the way
   without having to touch the board's own layout. */
.credits {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 4px 8px;
  background: rgba(255, 255, 255, .85);
  font-size: x-small;
  line-height: 1.4;
}
#board {
  position: absolute;
  width: 98%;
  height: 70%;
  display: flex;
  flex-direction: column;
}