* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  height: 100vh;
  background-color: rgb(66, 66, 66);
  display: flex;
}

#loader-background{
  position: fixed;
  top: 0;
  width: 100%;
  height: 100%;
  background: rgb(66, 66, 66);
  z-index: 1000;
}

#loader{
  position: absolute;
  left: 50%;
  top: 50%;
  z-index: 1001;
  width: 150px;
  height: 150px;
  margin: -75px 0 0 -75px;
  border: 16px solid #f3f3f3;
  border-radius: 50%;
  border-top: 16px solid #3498db;
  width: 120px;
  height: 120px;
  animation: spin 2s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

#gameOver{
  top: 50%;
  left: 25%;
  display: none;
  position: absolute;
  width: 50%;
  background: rgb(66, 66, 66);
  z-index: 900;
}

#playAgain{
  top: -8%;
  left: 78%;
  position: absolute;
  width: 50%;
  z-index: 950;
}

.gameContainer {
  width: 500px;
  height: 500px;
  margin: auto;
  display: flex;
  flex-wrap: wrap;
  perspective: 1000px;
}

.card {
  width: 23%;
  height: 23%;
  margin: 5px;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.3s;
  cursor: pointer;
  background-color: transparent;
}

.card:active {
  transform: scale(0.95);
  transition: transform 0.2s ease-in-out;
}

.card.flip {
  transform: rotateY(180deg);
  cursor: pointer;
}

.front,
.back {
  background-color: #807f7f;
  width: 100%;
  height: 100%;
  padding: 10px;
  border-radius: 4px;
  position: absolute;
  backface-visibility: hidden;
}

.front {
  transform: rotateY(180deg);
}