body {
    font-family: serif;
}

h1,
h2,
h3 {
    font-family: sans-serif;
}

h1 {
    background-color: #def;
    padding: 10px;
    margin-left: 10px;
}

h2 {
    background-color: #abc;
    padding: 10px;
    margin-left: 60px;
}

h3 {
    background-color: #789;
    padding: 10px;
    margin-left: 110px;
}

div {
    background-color: #ddd;
    padding: 20px;
    margin-left: 110px;
}

p {
    background-color: #eee;
    padding: 20px;
}

.red {
    background-color: rgb(184, 12, 40);
}

#imgMelou,
#butMelou {
    display: block;
    margin-left: auto;
    margin-right: auto;
}