body {
    margin: 0;
    padding: 0;
    background: linear-gradient(135deg, #002f4b, #006494, #00b4d8, #90e0ef);
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
    min-height: 100vh;
    height: auto;
    overflow-y: auto;
    font-family: sans-serif;
}

.titulo {
    margin-top: 30px;
    width: 100%;
    text-align: center;
    font-size: 55px;
    font-weight: bold;
    color: white;
    text-shadow: 2px 2px 5px #000;
    z-index: 10;
}

.game-container {
    display: grid;
    grid-template-columns: repeat(4, 226.36px);
    grid-gap: 20px;
    padding: 20px;
    border-radius: 12px;
}

.card {
    width: 226.36px;
    height: 347.99px;
    perspective: 1000px;
    cursor: pointer;
}

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

.card:not(.flipped):hover .card-back {
    animation: shine 2s infinite linear;
}

@keyframes shine {
    0% { filter: brightness(1); }
    50% { filter: brightness(1.2); }
    100% { filter: brightness(1); }
}

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

.card-front,
.card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 10px;
    overflow: hidden;
    top: 0;
    left: 0;
}

.card-front {
    transform: rotateY(180deg);
    z-index: 2;
}

.card-back {
    transform: rotateY(0deg);
    z-index: 1;
}

.card-back img,
.card-front img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

/* Banner de victoria centrado */
#victoryBox {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: #cceeff;
    color: #003973;
    padding: 40px 60px;
    border-radius: 20px;
    font-size: 24px;
    font-weight: bold;
    text-align: center;
    z-index: 999;
    animation: fadePop 0.5s ease-out;
    box-shadow: 0 0 25px rgba(0,0,0,0.3);
}

#victoryBox h2 {
    margin-bottom: 10px;
    font-size: 32px;
}

#victoryBox p {
    margin: 10px 0;
    font-size: 22px;
}

@keyframes fadePop {
    0% {
        transform: translate(-50%, -50%) scale(0.8);
        opacity: 0;
    }
    100% {
        transform: translate(-50%, -50%) scale(1);
        opacity: 1;
    }
}

/* Cronómetro */
#timer {
    position: fixed;
    top: 20px;
    right: 30px;
    font-size: 20px;
    color: white;
    background: rgba(0,0,0,0.4);
    padding: 8px 16px;
    border-radius: 8px;
    z-index: 999;
}