.responsive-heading {
    font-size: 3em;
    text-align: center;
    text-shadow: 2px 3px 2px black;
    font-weight: bold;
    margin-bottom: 30px;
}

@media only screen and (max-width: 768px) {
    .responsive-heading {
        font-size: 2em;
   /*     text-align: center;*/
    }
}