section > .content h2 {
    margin: 40px 0;
}



section#introduction > .content{
    max-width: none;
}

section#presentation > .content,
section#extra-1 > .content
 {
    margin: 40px 20px; 
    padding:10px;
}

main#index > section#presentation > .content {
    transition-delay: 0.5s;
    transition-duration: 4s;
}