body {
    font-family: Arial;
    padding: 3rem;
}

video {
    position: fixed;
    bottom: 0;
    right: 0;
    width: 100%;
}

.conteneur{
    z-index: 1;
    position: relative;
}

.contenu {
    position: sticky;
    top: 30%;
}

h1 {
    background-color: white;
    display: inline-block;
    padding: 10px;
    margin: 0;
}

/*
Liste des timecodes :
Boum : 00:21 7.78%
Feu : 01:02 11.85%
Fumée : 02:15 27.78%
Fin : 05:11 59.63%
Total : 09:00 100%
*/
section:nth-of-type(1) {
    height: 1200px;
}
section:nth-of-type(2) {
    height: 840px;
}
section:nth-of-type(3) {
    height: 1280px;
}
section:nth-of-type(4) {
    height: 3000px;
}
section:nth-of-type(5) {
    height: 4480px;
}