.pbs-promo {
    margin: 1.5em 0;
    text-align: center;
}

.pbs-promo a {
    display: inline-block;
    line-height: 0;
    max-width: 100%;
}

.pbs-promo img {
    border: 0;
    display: block;
    height: auto;
    max-width: 100%;
}