:root {
    --primary-color: #4CAF50;
    --secondary-color: #2196F3;
    --accent-color: #FF4081;
    --background-color: #f5f5f5;
    --text-color: #333;
}
/* Estilos para la carta animada */
.card-container {
    display: block;
    perspective: 1000px;
    width: 100%;
    max-width: 400px;
    margin: 10px auto;
    height: 70px;
}

.card {
    position: relative;
    width: 100%;
    height: 100%;
    transform-style: preserve-3d;
    transition: transform 1.5s;
    transform: rotateY(180deg);
}

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

.card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    /* padding: 20px;
    border-radius: 15px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.2); */
}

.card-front {
    /* background: linear-gradient(135deg, var(--primary-color), var(--secondary-color)); */
    color: var(--primary-color);
    font-size: 24px;
    text-align: center;
}

.card-back {
    /* background: linear-gradient(135deg, var(--primary-color), var(--secondary-color)); */
    transform: rotateY(180deg);
    font-size: 36px;
    color: white;
}

.question-reveal {
    opacity: 0;
    transform: translateY(0px);
    animation: revealQuestion 1s forwards;
    animation-delay: 1.5s;
}

@keyframes revealQuestion {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}