body {
    font-family: Arial, sans-serif;
    margin: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    flex: 1 0 auto;
}

.conteneur {
    flex: 1 0 auto;
    margin: 100px;
}

h2{
    text-align: center;
}
.conteneur div{
    display: flex;
    border: solid;
    margin: 3% 10%;
}
.conteneur img{
    display: block;
    height: 150px;
    width: auto;
}
.position_body{
    display: flex;
    align-items: center;
    justify-content: center;
}
.conteneur > div{
    justify-content: space-between; 
}