.main_contents {
    width: 100%;
    margin: 30px auto 0 auto;
}

@media (min-width:1024px) {

    .video_grid {
        display: grid;
        grid-template-columns: repeat(2,1fr);
        gap: 60px;
        max-width: 1200px;
        margin: 0 auto;
    }
}