@media screen and (min-width: 0px) {
    body {
        font-family: 'my_font', sans-serif;
    }
    .panel .sections>div {
        font-family: 'my_font', sans-serif;
        font-size: 14px;
        line-height: 1.3;
    }
}

@media screen and (min-width: 768px) {
    .panel .sections>div {
        font-size: 16px;
        line-height: 1.4;
    }
}