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

header {
    h1 {
        font-size: 3rem;
        margin: 0;
    }
    background-color: #6a1b9a;
    color: white;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

button {
    padding: 0.5rem 1rem;
    font-weight: bold;
    background-color: #fff;
    border: 2px solid #6a1b9a;
    border-radius: 4px;
    cursor: pointer;
}

.game {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    max-width: 600px;
    margin: 2rem auto;
}

.card {
    perspective: 1000px;
    width: 100%;
    aspect-ratio: 1 / 1;
    cursor: pointer;
}

.card-inner {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.6s;
}

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

.card-front,
.card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 8px;
}

.card-front {
    background-color: #d1c4e9;
}

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

/* ----------------------------------------------------MediaQuery-------------------------------------------------- */

/* screen < 480px */
@media (max-width: 480px) {
    header h1 {
        font-size: 1.5rem;
    }

    .card {
        width: 80%;
        margin: 0 auto;
    }

    .game {
        gap: 8px;
        max-width: 350px;
        margin: 2rem auto;
    }
}

/* screen 481 - 768px */
@media (min-width: 481px) and (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .card {
        
        perspective: 1000px;
        width: 80%;
        margin: 0 auto;
    }

    .game {
        gap: 20px 0px;
        max-width: 600px;
        margin: 4rem auto;
    }
}

/* screen 768px - 1024px */
@media (min-width:768px) and (max-width: 1024px) {
    .game {
        grid-template-columns: repeat(4, 1fr);
    }

    .card {
        width: 90%;
        margin: 0 auto;
    }

    
}

/* screen > 1025px */
@media (min-width: 1025px) {
    header h1 {
        font-size: 3rem;
    }

    .game {
        grid-template-columns: repeat(4, 1fr);
    }

    .card {
        width: 100%;
        margin: 0 auto;
    }
}