body
{
    margin: 0px;
    margin: auto;
    max-width: 50rem;
    overflow: hidden;
}

section
{
    height: 100vh;
    max-width: 50rem;
}

p
{
    text-align: center;
    margin-top: 50vh; /* poussé de la moitié de hauteur de viewport */
}

nav
{
    text-align: center;
}

a
{
    text-decoration: none;
    padding: 5px;
    margin: 5px;
}

li:nth-child(2n+1) > a
{
    background-color: lightgreen;
    border-radius: 60px;
}
li:nth-child(2n) > a
{
    background-color: lightblue;
    border-radius: 60px;
}