.yandex-ads {
    width: 100%;
    max-width: 400px;
    margin: 0 auto 30px;
}

@media (max-width: 949px) {
    .yandex-ads--pc {
        display: none;
    }
}

@media (min-width: 950px) {
    .yandex-ads--mob {
        display: none;
    }
}