#lien {
    display: flex;
    text-align: center;
    align-items: center;
    justify-content: center;
}

#lien div {
    margin: 10px;

}

#lien a {
    position: relative;
    text-decoration: none;
    display: block;
    color: black;
    padding: 10px 5px;
    margin: 1em;
    text-align: center;
    transition: transform 0.3s ease;

}

#lien a::after {
    content: "";
    position: absolute;
    left: 50%;
    bottom: -3px;
    width: 0;
    height: 2px;
    background: goldenrod;
    transition: width 0.3s ease, left 0.3s ease;

}

#lien a:hover::after {
    width: 100%;
    left: 0;


}


#lien a:hover {
    transform: translateY(-5px);
}



#lien a.first {
    margin-left: 10em;
}



#lien a.last {
    margin-right: 10em;
}

main img {
    width: 35%;
    margin: 5px;
}

.favicone {
    width: 32px;
}

ul li {
    list-style: none;
}

.W3C {
    transition-duration: 300ms;
}

.W3C:hover {
    transform: scale(2);
}

.arbo {
    width: 15%;
}