body, html {height: 100%; width: 100%;}
#mainHeader{
    padding-top: 7em;
    padding-bottom: 7em;
}
body {

    background-color: #111;
    background-image: -webkit-radial-gradient(circle , #222, #000);
    background-image:    -moz-radial-gradient(circle , #222, #000);
    background-image:         radial-gradient(circle , #222, #000);
    margin: 0;
}

#contenu p{
    font-size: 1.3em;
    display: grid;
    text-align: center;
    background: rgba(0, 0, 0, 0.4);
    border: 0 none;
    padding: 2em;
    box-sizing: border-box;
    margin: 5% 5%;
    z-index: 4;
    color: #ddd;
    font-weight: 300;
    line-height: 1.8em;
    overflow: hidden;
}
em {
    font-weight: 700;
    font-style: italic;
    font-size: 1.5em;
    text-transform: capitalize;
    color: rgb(236, 20, 20);
    letter-spacing: .3em;
    padding: 1em;
}
#menu a{
    color: #f9f9f9;
}
@media (max-width: 1300px) {
    button a {
        font-size: 0.9rem;
    }
}

@media (max-width: 1200px) {
    .contenu em {
        font-size: 1.5rem;
    }
    .contenu p {
        margin: -15% 4% 2% 4%;
    }
    .contenu em {
        font-size: 1.5rem;
    }
    button a {
        font-size: 0.8rem;
    }
}
@media (max-width: 600px){
    .contenu em {
        font-size: 1.2rem;
    }
    button a {
        font-size: 0.6rem;
    }
    #contenu p{
        padding: 1%;
        text-align: center;
        word-spacing: 0;
        font-size: .9em;
        margin: 10% 5%;
        background: rgba(0, 0, 0, 0.1);
    }
}