body {
  margin: 0;
  font-family: 'Segoe UI', sans-serif;
  background: radial-gradient(circle, #1e1e2f, #0f0f1a);
  color: white;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
}

/* Container */
.container {
  text-align: center;
  padding: 20px;
  border-radius: 20px;
  backdrop-filter: blur(25px);
  background: rgba(255,255,255,0.05);
  box-shadow: 0 0 40px rgba(0, 198, 255, 0.2);
}

/* Top Bar */
.top-bar {
  display: flex;
  justify-content: space-between;
  margin-bottom: 10px;
}

/* Info */
.info {
  display: flex;
  justify-content: space-around;
  margin-bottom: 15px;
}

/* Board */
.game-board {
  display: grid;
  gap: 10px;
  justify-content: center;
}

/* Card */
.card {
  width: 70px;
  height: 70px;
  perspective: 1000px;
}

.card-inner {
  width: 100%;
  height: 100%;
  transition: transform 0.5s;
  transform-style: preserve-3d;
  position: relative;
}

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

.card-front, .card-back {
  position: absolute;
  width: 100%;
  height: 100%;
  border-radius: 12px;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 28px;
  backface-visibility: hidden;
}

.card-front {
  background: #222;
  box-shadow: 0 0 10px #000;
}

.card-back {
  background: linear-gradient(135deg, #00c6ff, #0072ff);
  transform: rotateY(180deg);
  box-shadow: 0 0 15px #00c6ff;
}

/* Glow when matched */
.card.matched .card-back {
  box-shadow: 0 0 25px #00ffcc, 0 0 40px #00ffcc;
}

/* Button */
button, select {
  padding: 8px 12px;
  border-radius: 10px;
  border: none;
  background: #00c6ff;
  color: white;
  cursor: pointer;
}

button:hover {
  background: #0072ff;
}

/* Popup */
.popup {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: none;
  justify-content: center;
  align-items: center;
  background: rgba(0,0,0,0.8);
}

.popup-content {
  background: white;
  color: black;
  padding: 20px;
  border-radius: 15px;
}