.conteneur-flexible{
    display: flex;
    font-size: 20px;
    background-color: #0AD; /*Bleu*/
    border: 2px solid blue;
    box-sizing: border-box;
    margin: 10px 0px;
}
.ligne{
    flex-flow: row wrap;
}
.ligne-reverse{
    flex-flow: row-reverse wrap;
}
.debut{
    justify-content: flex-start;
}
.fin{
    justify-content: flex-end;
}
.element-flexible{
    flex: 0 0 10%;
    width: 25%;
    height: 25%;
    background-color: #0DA; /*Vert*/
    padding: 10px 0px;
    text-align: center;
    border: 2px solid green;
    box-sizing: border-box;
    margin: 5px;
}