/* por causa do fixed-top do navbar*/
body {
    padding-top: 56px;
    background: url('../imagens/background.webp') center / cover no-repeat fixed;
}

/* transparência da imagem*/
body::before {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6); /* transparência */
    z-index: -1;
}

/* caixa central */
.main {
    min-height: calc(100vh - 112px); /* 56px topo + 56px rodapé */
    display: flex;
    justify-content: center;
    align-items: center;
}

/* links exemplos */
.imagem-card {
    position: relative;
}

.descricao {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;

    padding: 10px;
    background: rgba(0, 0, 0, 0.6);
    color: #fff;
    text-align: center;

    opacity: 0;
    transition: opacity 0.3s ease;
}

.galeria a:hover .descricao {
    opacity: 1;
}