body {
  font-family: sans-serif;
  text-align: center;
  background: #f0f0f0;
}

h1 {
  margin-top: 20px;
}

#restartBtn {
  padding: 10px 20px;
  font-size: 16px;
  margin: 10px;
  cursor: pointer;
}

.game-board {
  display: grid;
  grid-template-columns: repeat(4, 100px);
  gap: 10px;
  justify-content: center;
  margin-top: 20px;
}

.card {
  width: 100px;
  height: 100px;
  background: #3498db;
  border-radius: 8px;
  cursor: pointer;
  position: relative;
  overflow: hidden;
  transition: transform 0.2s;
}

.card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: none;
}

.card.flipped img {
  display: block;
}