body {
    font-family: 'Arial', sans-serif;
    background-image: url(img/peta.png);
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center center;
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.btn-start-container{
    background-color: rgba(0, 0, 0, 0.7);
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    position: absolute;
    z-index: 99;
}

.btn-start-container button{
    outline: none;
    border: none;
    padding: 10px 25px;
    border-radius: 10px;
    background: linear-gradient(red, white);
    font-weight: 900;
    color: #000;
    cursor: pointer;
    transition: 0.5s;
}

.btn-start-container button:hover{
    box-shadow: 0px 0px 10px #fff;
}

.game-container {
    text-align: center;
    position: relative;
}

.flag-container{
    position: absolute;
    top: -60px;
    left: 50%;
    transform: translate(-50%, -50%);
    animation: flag 1.5s infinite;
}

.flag-container img{
    width: 150px;
}

.game-board {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    max-width: 600px;
    margin: 0 auto;
}

.card {
    width: 100px;
    height: 100px;
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    cursor: pointer;
    perspective: 1000px;
    transform-style: preserve-3d;
    transition: transform 0.3s ease;
}

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

.card-inner {
    width: 100%;
    height: 100%;
    position: relative;
    transform-style: preserve-3d;
    transition: transform 0.3s ease;
}

.card-front,
.card-back {
    width: 100%;
    height: 100%;
    position: absolute;
    backface-visibility: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    color: transparent;
    box-shadow: 0px 0px 10px grey;
    border-radius: 5px;
}

.card-front {
    background: #ff0909;
    background-image: url(img/hut.png);
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    border: 1px solid #ffffff;
}

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

.matched {
    visibility: hidden;
}

@keyframes flag {
    50%{
        top: -40px;
    }
    100%{
        top: -60px;
    }
}

@media(max-width:480px) {
    .card {
        width: 60px;
        height: 60px;
    }
    .game-board {
        max-width: 400px;
    }
}