@media screen and (max-width: 600px) {
    .custom-caption {
        font-size: 2rem !important;
    }
}

.custom-caption{
    position: absolute;
    font: 700 3.5rem Raleway, Verdana, sans-serif;
    color: floralwhite;
    padding: 10px;
    text-shadow: 2px 2px 10px #000;
    left: 15px;
    bottom: 10px;
}