.sponsors-grid {
    margin: 0 auto;
    display: grid;
    grid-template-columns: auto;
}


/* .sponsors--default .sponsors__sponsor__image .mm-box-letter {
    position: relative;
    top: 0px;
    width: 40px;
    height: 40px;
    font-size: 16px;
    transition: all 300ms ease-out;
} */


/*  ---  640px  --- */

@media screen and (min-width: 640px) {
    .sponsors-grid {
        grid-template-columns: 1fr 1fr;
    }
    .card-box:nth-child(4n - 3) {
        border-right: 2px solid #e8e7e7;
        border-bottom: 2px solid #e8e7e7;
    }
    .card-box:nth-child(4n - 3):nth-last-child(1),
    .card-box:nth-child(4n - 3):nth-last-child(2),
    .card-box:nth-child(4n - 3):nth-last-child(3),
    .card-box:nth-child(4n - 3):nth-last-child(4) {
        border-bottom: 0;
    }
    .card-box:nth-child(4n - 2) {
        border-right: 2px solid #e8e7e7;
        border-bottom: 2px solid #e8e7e7;
    }
    .card-box:nth-child(4n - 2):nth-last-child(1),
    .card-box:nth-child(4n - 2):nth-last-child(2),
    .card-box:nth-child(4n - 2):nth-last-child(3) {
        border-bottom: 0;
    }
    .card-box:nth-child(4n - 1) {
        border-right: 2px solid #e8e7e7;
        border-bottom: 2px solid #e8e7e7;
    }
    .card-box:nth-child(4n - 1):nth-last-child(1),
    .card-box:nth-child(4n - 1):nth-last-child(2) {
        border-bottom: 0;
    }
    .card-box:nth-child(4n) {
        border-bottom: 2px solid #e8e7e7;
    }
    .card-box:nth-child(4n):last-child {
        border-bottom: 0;
        border-right: 0;
    }
}


/*  ---  998px  --- */

@media screen and (min-width: 998px) {
    .sponsors-grid {
        grid-template-columns: 1fr 1fr 1fr 1fr;
    }
}