:root {
  --primary-color: #667eea;
  --secondary-color: #764ba2;
  --accent-color: #f093fb;
  --success-color: #4facfe;
  --error-color: #f093fb;
  --background-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --card-bg: rgba(255, 255, 255, 0.1);
  --card-border: rgba(255, 255, 255, 0.2);
  --text-primary: #ffffff;
  --text-secondary: rgba(255, 255, 255, 0.8);
  --shadow-light: rgba(255, 255, 255, 0.25);
  --shadow-dark: rgba(0, 0, 0, 0.25);
  --card-size: clamp(70px, 12vw, 120px);
  --border-radius: 20px;
  --transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: "Inter", sans-serif;
  background: var(--background-gradient);
  min-height: 100vh;
  overflow-x: hidden;
  position: relative;
}

body::before {
  content: "";
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(
      circle at 20% 80%,
      rgba(120, 119, 198, 0.3) 0%,
      transparent 50%
    ),
    radial-gradient(
      circle at 80% 20%,
      rgba(255, 255, 255, 0.1) 0%,
      transparent 50%
    ),
    radial-gradient(
      circle at 40% 40%,
      rgba(240, 147, 251, 0.2) 0%,
      transparent 50%
    );
  pointer-events: none;
  z-index: -1;
}

.container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  padding: 20px;
  gap: 20px;
}

/* Header Styles */
.header {
  background: rgba(255, 255, 255, 0.1);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  border: 1px solid var(--card-border);
  border-radius: var(--border-radius);
  padding: 20px;
  text-align: center;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.header h1 {
  font-family: "Poppins", sans-serif;
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  font-weight: 700;
  color: var(--text-primary);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
  margin-bottom: 10px;
}

.header p {
  color: var(--text-secondary);
  font-size: clamp(0.9rem, 2vw, 1.1rem);
  font-weight: 400;
}

/* Game Info Styles */
.game-info {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 30px;
  flex-wrap: wrap;
}

.info-card {
  background: rgba(255, 255, 255, 0.15);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  border: 1px solid var(--card-border);
  border-radius: 15px;
  padding: 15px 25px;
  text-align: center;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.2);
  transition: var(--transition);
}

.info-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

.info-card h3 {
  color: var(--text-primary);
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 5px;
}

.info-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.attempts-count {
  font-size: 1.5rem !important;
  font-weight: 700 !important;
  color: var(--accent-color) !important;
}

/* Game Board Styles */
.game-board {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px 0;
}

.cards-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: clamp(10px, 2vw, 20px);
  max-width: 600px;
  width: 100%;
  justify-content: center;
  align-items: center;
}

/* Card Styles - Completely Redesigned */
.memory-card {
  position: relative;
  width: var(--card-size);
  height: var(--card-size);
  perspective: 1000px;
  cursor: pointer;
}

.card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.memory-card.flipped .card-inner {
  transform: rotateY(180deg);
}

.card-face {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: var(--border-radius);
  display: flex;
  justify-content: center;
  align-items: center;
  overflow: hidden;
}

/* Front Face (Question Mark) */
.card-front {
  background: linear-gradient(
    145deg,
    rgba(255, 255, 255, 0.2),
    rgba(255, 255, 255, 0.05)
  );
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  border: 1px solid var(--card-border);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.3), inset 0 -1px 0 rgba(0, 0, 0, 0.1);
  transition: var(--transition);
}

.card-front::before {
  content: "";
  position: absolute;
  top: 2px;
  left: 2px;
  right: 2px;
  bottom: 2px;
  background: linear-gradient(
    145deg,
    rgba(255, 255, 255, 0.1),
    rgba(255, 255, 255, 0.02)
  );
  border-radius: calc(var(--border-radius) - 2px);
  pointer-events: none;
}

.card-front i {
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  color: var(--text-primary);
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  transition: var(--transition);
}

/* Back Face (Content) */
.card-back {
  background: linear-gradient(
    145deg,
    rgba(255, 255, 255, 0.25),
    rgba(255, 255, 255, 0.1)
  );
  -webkit-backdrop-filter: blur(25px);
  backdrop-filter: blur(25px);
  border: 1px solid rgba(255, 255, 255, 0.3);
  transform: rotateY(180deg);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.4), inset 0 -1px 0 rgba(0, 0, 0, 0.1);
}

.card-back::before {
  content: "";
  position: absolute;
  top: 3px;
  left: 3px;
  right: 3px;
  bottom: 3px;
  background: linear-gradient(
    145deg,
    rgba(255, 255, 255, 0.15),
    rgba(255, 255, 255, 0.05)
  );
  border-radius: calc(var(--border-radius) - 3px);
  pointer-events: none;
}

.card-content {
  font-size: clamp(1.8rem, 5vw, 3rem);
  z-index: 1;
  position: relative;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

/* Card Hover Effects */
.memory-card:hover .card-front {
  transform: translateY(-3px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.4), inset 0 -1px 0 rgba(0, 0, 0, 0.1);
}

.memory-card:hover .card-front i {
  transform: scale(1.1);
  color: var(--accent-color);
}

/* Card States */
.memory-card.matched .card-back {
  background: linear-gradient(
    145deg,
    rgba(79, 172, 254, 0.3),
    rgba(79, 172, 254, 0.1)
  );
  border: 2px solid var(--success-color);
  box-shadow: 0 0 30px rgba(79, 172, 254, 0.4), 0 12px 40px rgba(0, 0, 0, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.4);
}

.memory-card.error .card-back {
  background: linear-gradient(
    145deg,
    rgba(240, 147, 251, 0.3),
    rgba(240, 147, 251, 0.1)
  );
  border: 2px solid var(--error-color);
  box-shadow: 0 0 30px rgba(240, 147, 251, 0.4), 0 12px 40px rgba(0, 0, 0, 0.15),
    inset 0 1px 0 rgba(255, 255, 255, 0.4);
  animation: shake 0.5s ease-in-out;
}

.memory-card.disabled {
  pointer-events: none;
  opacity: 0.7;
}

/* Animations */
@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-5px);
  }
  75% {
    transform: translateX(5px);
  }
}

@keyframes pulse {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
}

.memory-card.matched {
  animation: pulse 0.6s ease-in-out;
}

/* Toast Notification */
.toast {
  position: fixed;
  bottom: 30px;
  right: 30px;
  background: rgba(255, 255, 255, 0.95);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  color: #333;
  padding: 15px 25px;
  border-radius: 15px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.3);
  transform: translateX(100%);
  transition: transform 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  z-index: 1000;
  font-weight: 500;
}

.toast.show {
  transform: translateX(0);
}

/* Footer */
.footer {
  background: rgba(255, 255, 255, 0.1);
  -webkit-backdrop-filter: blur(20px);
  backdrop-filter: blur(20px);
  border: 1px solid var(--card-border);
  border-radius: var(--border-radius);
  padding: 20px;
  text-align: center;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1),
    inset 0 1px 0 rgba(255, 255, 255, 0.2);
}

.footer p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 10px;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--text-primary);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
  padding: 5px 10px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.1);
}

.footer-links a:hover {
  color: var(--accent-color);
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

/* Responsive Design */
@media (max-width: 768px) {
  .container {
    padding: 15px;
    gap: 15px;
  }

  .cards-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
  }

  .game-info {
    gap: 15px;
  }

  .info-card {
    padding: 12px 20px;
  }

  .toast {
    bottom: 20px;
    right: 20px;
    left: 20px;
    transform: translateY(100%);
  }

  .toast.show {
    transform: translateY(0);
  }
}

@media (max-width: 480px) {
  .cards-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .header {
    padding: 15px;
  }

  .footer-links {
    gap: 15px;
  }
}

/* Responsive Design */
@media (max-width: 768px) {
  .cards-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}