body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.memory-container {
    text-align: center;
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.board {
    display: grid;
    grid-template-columns: repeat(4, 70px);
    grid-gap: 10px;
    justify-content: center;
    margin-bottom: 1rem;
}

.card {
    width: 70px;
    height: 70px;
    background-color: #1f2937;
    color: white;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 2rem;
    cursor: pointer;
    border-radius: 5px;
    user-select: none;
}
.card.flipped {
    background-color: #10b981;
}