.card-action {
    flex-direction: column;
    /* impila verticalmente */
    align-items: stretch;
    /* allinea a tutta larghezza */
    gap: 10px;
    /* spazio tra pulsante e link */
}

.card-action a.btn-flat {
    text-align: center;
    /* centra il link */
    width: 100%;
    /* occupa tutta la riga */
}

@media only screen and (max-width: 600px) {
    h5.activation-title {
        font-size: 12px !important;
        line-height: 1.3em !important;
        display: block;
        margin-top: 10px !important;
        /* 🔽 riduce lo spazio sopra */
        margin-bottom: 5px !important;
        /* 🔽 riduce lo spazio sotto */
    }

    .card-content p.login-subtitle {
        font-size: 18px !important;
        color: #1565c0 !important;
        /* blu elegante */
        font-weight: 600 !important;
        margin-top: 5px !important;
        margin-bottom: 10px !important;
    }
}