body {
    font-family: Arial, sans-serif;
    background-color: #f0f0f0;
    text-align: center;
    margin: 0;
    padding: 0;
}

.game-container {
    width: 800px;
    margin: 0 auto;
    background-color: #fff;
    padding: 20px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
}

h1 {
    margin: 0;
}

#game {
    width: 600px;
    margin: 20px auto;
    text-align: left;
}

#cards {
    display: grid;
    grid-template-columns: repeat(4, 100px);
    grid-template-rows: repeat(3, 100px);
    gap: 10px;
    margin-bottom: 20px;
}

.card {
    width: 100px;
    height: 100px;
    background-color: #007bff;
    color: #fff;
    font-size: 1.2em;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    user-select: none;
    perspective: 1000px;
    transform-style: preserve-3d;
    transition: transform 0.5s;
}

.card .back,
.card .front {
    width: 100%;
    height: 100%;
    position: absolute;
    display: flex;
    align-items: center;
    justify-content: center;
    backface-visibility: hidden;
}

.card .back {
    transform: rotateY(0deg);
    background-color: #007bff;
}

.card .front {
    transform: rotateY(180deg);
    background-color: #007bff;
    color: #fff;
    font-size: 1.2em;
}

.card.flipped .back {
    transform: rotateY(180deg);
}

.card.flipped .front {
    transform: rotateY(0deg);
}

button {
    padding: 10px 20px;
    background-color: #007bff;
    color: #fff;
    border: none;
    cursor: pointer;
}

button:hover {
    background-color: #0056b3;
}