.caja {
    border-radius: 4px;
    border: solid 1px;
    margin-bottom: 2rem;
    padding: 1.5rem;
    text-align: center;
}

#submit_mensaje:disabled{
    background-color: grey;
    pointer-events: none;}

.rojo{color: #ff473e;}
.oculto{display: none;}
.verde{color: #28a454;}