.board {
  display: grid;
  grid-template-columns: repeat(4, 80px);
  grid-gap: 8px;
  justify-content: center;
  margin: 20px auto;
}
.card {
  width: 80px;
  height: 80px;
  background: #f0f0f0;
  border: 2px solid #999;
  font-size: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  user-select: none;
}
.card.flipped {
  background: #fff;
}
.card.matched {
  background: #cfc;
  cursor: default;
}
#status {
  text-align: center;
  font-size: 1.2em;
  margin-top: 10px;
}