.conteneur {
    width: 830px;
    margin: auto
}

.bande1 {
    width: 800px;
    height: 150px;
    background: #093844;
    margin: auto
}

.bande2 {
    display: flex;
    float: left;
    margin: 15px 0px 15px 0px
}

.bande3 {
    display: flex;
    width: 880px;
}

.bande4 {
    width: 700px;
    height: 100px;
    background: #532736;
    margin: auto;
    margin-top: 15px;
}