@media screen and (min-width: 320px) and (max-width: 568px) {
    .box_404 {
        flex-direction: column-reverse; 
    }
    .er404 {
        width: 100%;
    }
    .n_404_img_block {
        width: 100%;
    }
    .img_404 {
        width: 100%;
    }
    .er404 b {
        font-size: 48px;
        margin-bottom: 20px;
        margin-top: 30px;
    }
    .er404 strong {
        font-size: 20px;
    }
    .er404 .or {
        font-size: 14px;
        align-self: center;
        align-items: center;
    }
    .er404 .begin {
        margin: 30px 0;
    }
}