.countdown-container {
    /*color: #333;*/
    margin: 0 auto;
    text-align: center;
}

.countdown-li {
    /*display: inline-block;*/
    font-size: 1.5em;
    list-style-type: none;
    /*padding: 1em;*/
    text-transform: uppercase;
    /*width:10rem;*/
}

    .countdown-li span {
        display: block;
        font-size: 4.5rem;
    }


@media all and (max-width: 768px) {
    #headline {
        font-size: 1.5rem;
    }

    .countdown-li {
        font-size: 1.4rem;
        /*width: calc(10rem * var(--smaller))*/
    }

        .countdown-li span {
            font-size: 2.5rem;
        }
}