:root {
    --text-color: #FFFFFF;
    --card-front-color: #1E1E2F;
    --card-back-color: #FF6F61;
    --highlight-color: #FFD700;
}

body {
    background: url('img/bg-desktop.webp') no-repeat center center fixed;
    background-size: cover;
    font-family: 'Montserrat', sans-serif;
    color: var(--text-color);
}

#container {
    display: flex; 
    flex-wrap: wrap;
    justify-content: space-between;
    padding: 4rem;
    gap: 2rem;
}

.cartao {
    margin: 1rem;
    height: 20rem;
    flex-grow: 1;
    flex-basis: calc(33% - 4rem);
    perspective: 1000px;
}

.cartao__conteudo {
    background-color: var(--card-front-color);
    text-align: center;
    height: 100%;
    transform-style: preserve-3d;
    transition: transform 400ms ease-in-out;
    border-radius: 1rem;
    box-shadow: 0 8px 20px rgba(0,0,0,0.4);
}

.cartao__conteudo h3 {
    color: var(--highlight-color);
    border: 1px solid var(--highlight-color);
    text-align: left;
    padding: 0.7rem;
    position: absolute;
    margin: 0.6rem;
    border-radius: 0.6rem;
    font-size: 1vw;
    backface-visibility: hidden;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.5);
}

.cartao__conteudo p {
    margin-top: 4rem;
    padding: 2rem;
    font-size: 1.4vw;
}

.cartao__conteudo__pergunta p {
    color: var(--text-color);
    font-weight: 600;
}

.cartao__conteudo__resposta p {
    color: var(--card-back-color);
    font-weight: 700;
}

.cartao.active .cartao__conteudo {
    transform: rotateY(180deg);
}

.cartao__conteudo__pergunta,
.cartao__conteudo__resposta {
    backface-visibility: hidden;
    position: absolute;
    height: 100%;
    width: 100%;
    box-sizing: border-box;
}

.cartao__conteudo__resposta {
    transform: rotateY(180deg);
    background-color: rgba(255, 111, 97, 0.2);
    border: 4px solid var(--card-back-color);
    border-radius: 1rem;
}

footer {
    background-color: #1E1E2F;
    color: var(--highlight-color);
    position: fixed;
    bottom: 0;
    width: 100%;
    height: 2.5rem;
    box-shadow: 0 -2px 10px rgba(0,0,0,0.5);
}

footer p {
    text-align: center;
    font-size: 0.7rem;
    margin-top: 0.6rem;
    font-family: 'Montserrat', sans-serif;
}

@media (max-width: 560px) {
    body {
        background: url('img/bg-mobile.webp') no-repeat center center;
        background-size: cover;
    }

    .cartao {
        flex: 1 0 calc(100% - 1rem);
    }

    .cartao__conteudo h3 {
        font-size: 3vw;
    }

    .cartao__conteudo p {
        font-size: 3.8vw;
    }
}