body{
    background-color: aliceblue;

}
div{
    background: url(../images/saut-en-longueur.jpg);
    background-size: cover;
    background-position: center;
    height: 400px;
}
h1{
    color: white;
}
#hauteur{
    background: url(../images/hauteur.jpg);
    background-size: cover;
    background-position: center;
}