/* Import Google Font - Poppins */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600;700&display=swap');
*{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
}
body{
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  background: #010630;
}
/* Overlay styles */
.overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5); /* Semi-transparent black */
  z-index: 1000;
}

/* Modal styles */
.modal {
  width: 100%;
  display: none;
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  background-color: #fff;
  padding: 20px;
  border-radius: 10px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
  z-index: 1001;
  font-size: 22px;
}

/* Close button styles */
.close-btn {
  position: absolute;
  top: 10px;
  right: 10px;
  cursor: pointer;
  background-color: #ff0000; /* Red */
  color: #fff; /* White */
  border: none;
  padding: 5px 10px;
  border-radius: 5px;
  font-size: 14px;
}

.close-btn:hover {
  background-color: #cc0000; /* Darker Red */
}

/* Next Page button styles */
#nextRoundBtn {
  background-color: #4CAF50; /* Green */
  color: #fff; /* White */
  border: none;
  padding: 10px 20px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 16px;
  margin-top: 20px;
  border-radius: 5px;
  cursor: pointer;
}

#nextRoundBtn:hover {
  background-color: #45a049; /* Darker Green */
}
.wrapper{
  padding: 25px;
  border-radius: 10px;
  background: #F8F8F8;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}
#game-info {
  margin-bottom: 20px;
  text-align: center;
}
header h1 {
  margin: 0;
  font-size: 2.5em;
  color: #343a40;
}
#game-info div {
  margin-bottom: 5px;
  color: #444;
}
#game-info #countdown {
  font-size: 20px;
  font-weight: bold;
}
#startGameBtn {
  font-size: 1.2em;
  padding: 10px 20px;
  background-color: #007bff;
  color: #ffffff;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}
#startGameBtn:hover {
background-color: #0056b3;
}
#flips {
  font-weight: bold;
}
#pairs {
  font-weight: bold;
}
.cards, .card, .view{
  display: flex;
  align-items: center;
  justify-content: center;
}
.cards{
  height: 400px;
  width: 400px;
  flex-wrap: wrap;
  justify-content: space-between;
  margin: 0 auto;
}
.cards .card{
  cursor: pointer;
  list-style: none;
  user-select: none;
  position: relative;
  perspective: 1000px;
  transform-style: preserve-3d;
  height: calc(100% / 4 - 10px);
  width: calc(100% / 4 - 10px);
}
.card.shake{
  animation: shake 0.35s ease-in-out;
}
@keyframes shake {
  0%, 100%{
    transform: translateX(0);
  }
  20%{
    transform: translateX(-13px);
  }
  40%{
    transform: translateX(13px);
  }
  60%{
    transform: translateX(-8px);
  }
  80%{
    transform: translateX(8px);
  }
}
.card .view{
  width: 100%;
  height: 100%;
  position: absolute;
  border-radius: 7px;
  background: #fff;
  pointer-events: none;
  backface-visibility: hidden;
  box-shadow: 0 3px 10px rgba(0,0,0,0.1);
  transition: transform 0.25s linear;
}
.card .front-view img{
  width: 90px;
}
.card .back-view img{
  max-width: 45px;
}
.card .back-view{
  transform: rotateY(-180deg);
}
.card.flip .back-view{
  transform: rotateY(0);
}
.card.flip .front-view{
  transform: rotateY(180deg);
}

@media screen and (max-width: 700px) {
  .cards{
    height: 350px;
    width: 350px;
    margin: 0 auto;
  }
  .card .front-view img{
    width: 75px;
  }
  .card .back-view img{
    max-width: 40px;
  }
}

@media screen and (max-width: 530px) {
  .cards{
    height: 300px;
    width: 300px;
    margin: 0 auto;
  }
  .card .front-view img{
    width: 70px;
  }
  .card .back-view img{
    max-width: 35px;
  }
}