:root {
  --bg-color: #050508;
  --neon-cyan: #0ff;
  --neon-pink: #f0f;
  --neon-purple: #b026ff;
  --card-bg: #11111a;
  --text-color: #fff;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: "Orbitron", sans-serif;
  background-color: var(--bg-color);
  color: var(--text-color);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow-x: hidden;
  background-image: radial-gradient(
    circle at center,
    #1a0b2e 0%,
    var(--bg-color) 100%
  );
}

header {
  text-align: center;
  margin: 2rem 0 1rem 0;
  z-index: 10;
}

h1 {
  font-size: 2.5rem;
  font-weight: 900;
  text-transform: uppercase;
  letter-spacing: 4px;
  color: #fff;
  text-shadow:
    0 0 5px #fff,
    0 0 10px var(--neon-cyan),
    0 0 20px var(--neon-cyan);
  margin-bottom: 1.5rem;
}

.hud {
  display: flex;
  gap: 2rem;
  justify-content: center;
  background: rgba(17, 17, 26, 0.8);
  padding: 15px 30px;
  border-radius: 12px;
  border: 1px solid rgba(0, 255, 255, 0.2);
  box-shadow: 0 0 20px rgba(0, 255, 255, 0.1);
  backdrop-filter: blur(10px);
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 80px;
}

.stat-label {
  font-size: 0.8rem;
  color: var(--neon-pink);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 5px;
}

.stat-value {
  font-size: 1.8rem;
  font-weight: 700;
  color: #fff;
  text-shadow: 0 0 10px var(--neon-pink);
}

.game-board {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 15px;
  padding: 20px;
  perspective: 1000px; /* Essential for 3D flip */
  width: 100%;
  max-width: 500px;
  z-index: 10;
}

.card {
  width: 100%;
  aspect-ratio: 1 / 1;
  position: relative;
  cursor: pointer;
  transform-style: preserve-3d; /* Required for backface visibility to work */
  transition: transform 0.6s cubic-bezier(0.4, 0.2, 0.2, 1);
}

/* This is the class Javascript will toggle */
.card.flipped {
  transform: rotateY(180deg);
}

.card.matched {
  transform: rotateY(180deg) scale(0.95);
  pointer-events: none;
}

.card-face {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden; /* Hides the reverse side when flipped */
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 3rem;
  border-radius: 12px;
  box-shadow: inset 0 0 20px rgba(0, 0, 0, 0.9);
}

/* The starting face with the question mark */
.card-front {
  background: linear-gradient(135deg, var(--card-bg), #000);
  border: 2px solid var(--neon-purple);
  box-shadow: 0 0 10px rgba(176, 38, 255, 0.3);
}

.card:hover:not(.flipped) .card-front {
  border-color: var(--neon-pink);
  box-shadow: 0 0 20px rgba(240, 0, 255, 0.6);
}

.card-front::after {
  content: "?";
  font-size: 2.5rem;
  color: rgba(176, 38, 255, 0.5);
  text-shadow: 0 0 10px var(--neon-purple);
}

/* The hidden face with the symbol */
.card-back {
  background: #0a0a0f;
  transform: rotateY(180deg); /* This flips it initially so it's on the back */
  border: 2px solid var(--neon-cyan);
  box-shadow:
    0 0 15px rgba(0, 255, 255, 0.4),
    inset 0 0 20px rgba(0, 255, 255, 0.2);
}

.card.matched .card-back {
  border-color: #39ff14;
  box-shadow:
    0 0 20px rgba(57, 255, 20, 0.6),
    inset 0 0 20px rgba(57, 255, 20, 0.2);
  animation: pulse-glow 2s infinite;
}

@keyframes pulse-glow {
  0% {
    box-shadow: 0 0 15px rgba(57, 255, 20, 0.4);
  }
  50% {
    box-shadow: 0 0 30px rgba(57, 255, 20, 0.8);
  }
  100% {
    box-shadow: 0 0 15px rgba(57, 255, 20, 0.4);
  }
}

.controls {
  margin: 2rem 0;
  z-index: 10;
}

.btn {
  background: transparent;
  color: var(--neon-cyan);
  border: 2px solid var(--neon-cyan);
  padding: 12px 35px;
  font-size: 1.2rem;
  font-weight: 700;
  border-radius: 8px;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 2px;
  transition: all 0.3s ease;
  box-shadow: 0 0 10px rgba(0, 255, 255, 0.2);
  font-family: "Orbitron", sans-serif;
}

.btn:hover {
  background: var(--neon-cyan);
  color: #000;
  box-shadow:
    0 0 20px var(--neon-cyan),
    0 0 40px var(--neon-cyan);
}

.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.9);
  display: flex;
  justify-content: center;
  align-items: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.4s ease;
  z-index: 500;
  backdrop-filter: blur(8px);
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: all;
}

.modal-box {
  background: #0a0a0f;
  padding: 40px 60px;
  border-radius: 16px;
  text-align: center;
  border: 2px solid var(--neon-pink);
  box-shadow: 0 0 40px rgba(240, 0, 255, 0.4);
  transform: translateY(50px) scale(0.9);
  transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.modal-overlay.active .modal-box {
  transform: translateY(0) scale(1);
}

.modal-box h2 {
  font-size: 3rem;
  color: #fff;
  text-shadow:
    0 0 10px var(--neon-pink),
    0 0 20px var(--neon-pink);
  margin-bottom: 20px;
}

.modal-box p {
  font-size: 1.5rem;
  margin-bottom: 20px;
  color: #ccc;
}

.highlight {
  color: var(--neon-cyan);
  font-weight: 700;
  text-shadow: 0 0 10px var(--neon-cyan);
}

.record-banner {
  display: none;
  color: #39ff14;
  font-size: 1.2rem;
  font-weight: bold;
  margin-bottom: 25px;
  text-shadow: 0 0 10px #39ff14;
  animation: pulse-glow 1s infinite alternate;
}

canvas#confetti {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: 499;
}

@media (max-width: 600px) {
  .game-board {
    gap: 10px;
    padding: 10px;
    max-width: 95vw;
  }
  .card-face {
    font-size: 2rem;
  }
  h1 {
    font-size: 2rem;
  }
  .hud {
    gap: 1rem;
    padding: 10px;
  }
  .stat-value {
    font-size: 1.4rem;
  }
  .modal-box {
    padding: 30px 20px;
    width: 90%;
  }
}