#main_img {
    width: 100%;
    padding-bottom: 30px;
}

#main_img ul {
    padding-top: 50px;
    width: 100%;
    display: flex;
}

#main_img ul li {
    width: 200px;
    margin-right: 10px;
    margin-left: 10px;
    text-align: center;
}

#main_img ul li img {
    width: 200px;
    height: 300px;
}

video {
    width: 900px;
    margin-top: 30px;
}