body {
    background: linear-gradient(to right, rgba(255, 253, 171, 0.89), rgba(219, 192, 246, 0.99));
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

h2 {
    font-family: 'Merriweather', serif;
    text-align: center;
    font-size: 2.5rem;
    color: #343a40;
    margin-bottom: 30px;
}

.title{
    background-color: rgba(219, 192, 246, 0.63);
}

.d-flex {
    justify-content: center;
    flex-wrap: wrap;
}

/* Estilos de las tarjetas flip */
.flip-card {
    background-color: transparent;
    width: 265px;
    height: 265px;
    margin: 10px;
    perspective: 1000px;
    display: flex;
    justify-content: center;
    align-items: center;

    /* Añadir animación de inicio */
    animation: zoomIn 0.8s ease-in-out;
}

/* Animación de zoom-in al cargar */
@keyframes zoomIn {
    from {
        transform: scale(0.5);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

.flip-card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.8s;
    transform-style: preserve-3d;
}

.flip-card-front, .flip-card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    padding: 20px;
}

/* Color común para todas las caras frontales */
.flip-card-front {
    background-color: rgba(255, 214, 3, 0.99);
    color: black;
    transform: rotateY(0deg);
}

/* Colores diferentes para cada tarjeta (trasera) */
.flip-card-back {
    transform: rotateY(180deg);
}

.flip-card:nth-child(1) .flip-card-back {
    background-color: rgba(219, 192, 246, 0.99);
}

.flip-card:nth-child(2) .flip-card-back {
    background-color: #87CEEB;
}

.flip-card:nth-child(3) .flip-card-back {
    background-color: #90EE90;
}

.flip-card:nth-child(4) .flip-card-back {
    background-color: #FF6347;
}

/* Efecto interactivo del giro */
.flip-card.girar .flip-card-inner {
    transform: rotateY(180deg);
}

/* Estilo del resultado */
#resultado {
    font-size: 18px;
    color: black;
    margin-bottom: 20px;
}

.calcular-btn {
    background-color: rgba(255, 181, 98, 0.86);
    color: white;
    border: none;
    padding: 10px 0;
    font-size: 18px;
    transition: background-color 0.3s ease;
    margin-top: auto;
    width: 80%;
    border-radius: 10px;
}

.calcular-btn:hover {
    background-color: #dcd01d;
    color: white;
}

/* Footer */
footer {
    background: linear-gradient(to right, rgba(66, 121, 255, 0.87), rgba(144, 95, 181, 0.99));
    color: white;
    padding: 30px 0;
    border-top: 15px solid rgba(219, 192, 246, 0.99);
    text-align: center;
    width: 100%;
    position: relative;
    bottom: 0;
    margin-top: auto;
}