body{
    background-color: #e9e9e9;
    padding: 0px;
    margin: 0px;
}
.menu{
    background-color: white;
    display: flex;
    align-items: center;
    justify-content: space-evenly;
}
.lien{
    margin-left:10px ;
    text-decoration: none;
    color: #7a7a7a;
    font-weight: 500;
    text-align: center;
    font-size: .8125em;
    letter-spacing: .1em;
    text-transform: uppercase;
    -webkit-transition: color .5s;
    transition: color .5s;
}
.principal{
    background-color: white;
    margin-left: 5%;
    margin-right: 5%;
    padding: 5%;
}