.main_frame {
    width: 70vw;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: flex-start;
    height: 100vh;
}

@media screen and (max-width: 999px) {
    .main_frame {
        width: 100%;
    }
}

.main_frame.center {
    justify-content: center;
}