/*.jumbotron { background:center no-repeat; background-size: cover;}*/

.box {
    display: block; /*一応block要素にしておく*/
    padding-top: 35%; /* 縦 ÷ 横 x　100 */
}
#bg1 {
    background: url(../photo/GENIUS_HEAD.png) no-repeat;
    background-position: center center;
    background-size: cover;
}

.signature {
    display: flex;
    justify-content: flex-end;
}