:root {
  --size: min(16vh, 16vw);
  --transition-time: 1s;
}

.container {
  display: flex;
  align-items: center;
  flex-direction: column;
}

.game {
  display: inline-grid;
  grid-template-rows: repeat(4, var(--size));
  grid-template-columns: repeat(4, var(--size));
  gap: min(2vh, 2vw);
}

.game-front {
  position: absolute;
}

.tile {
  height: var(--size);
  width: var(--size);
  background-color: aquamarine;
  border-radius: 4px;
  border: 1px solid rgb(214, 214, 214);
  box-shadow: 0 2px 2px 0 rgba(0, 0, 0, 0.15);
  cursor: pointer;
  font-size: calc(var(--size) / 2);
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  transition: var(--transition-time) transform;
  display: flex;
  justify-content: center;
  align-items: center;
}

.reset .tile {
  animation: bubbleEffect 1.5s;
}

@keyframes bubbleEffect {
  25% {
    scale: 0.4;
  }
  100% {
    scale: 1;
  }
}

.tile.back-tile {
  transform: rotateY(180deg);
}

.tile.active {
  background-color: yellowgreen;
  transform: rotateY(180deg);
}

.tile.back-tile.active {
  background-color: yellowgreen;
  transform: rotateY(360deg);
}

.tile.match {
  transform: rotateY(180deg);
}

.tile.back-tile.match {
  transform: rotateY(360deg);
}