#container-main {
    width: 30vw;
    margin-left: 35vw;
    margin-top: 30vh;
    text-align: center;
}

#center-img {
    width: 30vw;
}

#center-txt {
    font-family: Arial;
}

@media only screen and (max-width: 768px) {
    #container-main {
        margin-left: 5vw;
        margin-top: 30vh;
        align-content: center;
    }

    #center-img {
        width: 80vw;
    }
}