body {
    background-image: url('../images/strasbourg.jpg');
    background-size: cover;
    background-attachment: fixed;
    background-repeat: no-repeat;
    background-position: center;
    margin: 0;
    padding: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    word-break: normal;

}
h1{

    text-align: center;
}
p{
    text-align: justify;
}
.contenu {
    flex: 1;
    padding: 20px;
    background-color: rgba(255, 255, 255, 0.6);
    display: flex;
    flex-flow: row wrap;
    /*justify-content: space-between;*/
}
.centrer {
    /*background-color: rgba(255, 255, 255, 0.6);*/
}
.contenu > *{
    flex:100%;
}
@media (min-height: 900px) {
    .aside {
        flex: 1 auto;
    }
}
@media (min-height: 900px) {
.contenu {
    margin-top: 100px;
}
    .centrer {
        flex: 3 0px;
        /*flex-grow: 2;*/
    }
    p {
        font-size: large;
    }
}
footer {
    background-color: rgba(0, 0, 0, 0.7);
    color: white;
    padding: 20px;
    text-align: center;
}
footer p {
    text-align: center;
}