* {
    padding: 0;
    margin: 0;
}

#MenuEntete li {
    font-size: 1.2em;
    list-style-type: none;
    text-align: center;
}

#MenuEntete a {
    color: black;
    text-decoration: none;
    display: block;
    width: 100%;
    /* height: 4.375em; */
}

@media screen and (max-width:580px) {
    /* Petit écran */
    .GrandFormat,
    .TitreGrandFormat {
        display: none;
        float: left;
    }
    #ImgMenu,
    li {
        font-size: 0.875em;
        width: 100%;
        text-align: center;
        margin: 0 auto;
        margin-bottom: 0.313em;
        background-color: silver;
        cursor: pointer;
    }
    #ImgMenu {
        padding-top: 0.625em;
        padding-bottom: 0.625em;
    }
    #MenuEntete ul {
        display: none;
    }
    #MenuEntete li {
        padding-top: 1.250em;
        height: 2.938em;
    }
    #MenuEntete li:hover,
    #MenuEntete li:active {
        background-color: gray;
    }
}

@media screen and (min-width: 581px) and (max-width: 1023px) {
    /* Moyen écran */
    header {
        background-color: #f5f5f5;
        background-size: contain;
        height: 5.500em;
        margin: 0 auto;
        width: 100%;
    }
    .TitreGrandFormat,
    .PetitFormat,
    footer.GrandFormat {
        display: none;
    }
    #MenuEntete ul {
        display: block;
    }
    #MenuEntete li {
        width: 20%;
        float: left;
        background-image: url("../images/bouton.png");
        padding-top: 0.625em;
        height: 3.938em;
    }
    #MenuEntete li a:hover,
    #MenuEntete li a:active {
        color: #FF4E11;
        box-shadow: 0 -0.625em 0 0 #FF4E11;
    }
    li#logo a:hover,
    li#logo a:active {
        box-shadow: 0 -0.625em 0 0 transparent;
    }
    /* Styles pour la rubrique en cours */
    nav #en-cours a {
        color: #FF4E11;
        box-shadow: 0 -0.625em 0 0 #FF4E11;
    }
    #MenuEntete li.smallissime {
        width: 10%;
    }
    #nav {
        width: 100%;
        height: 5.500em;
        background-color: rgba(230, 230, 230, 0.9);
        margin: 0 auto;
        position: fixed;
        z-index: 9999;
    }
    #nav img {
        vertical-align: middle;
    }
}

@media screen and (min-width:1024px) {
    /* Grand écran */
    header {
        background-color: #f5f5f5;
        background-size: contain;
        height: 5.500em;
        margin: 0 auto;
        width: 100%;
    }
    .PetitFormat {
        display: none;
        float: left;
    }
    #MenuEntete ul {
        display: block;
        background-image: url("../images/bouton.png");
    }
    #MenuEntete li {
        float: left;
        padding-top: 0.625em;
        height: 3.938em;
    }
    #MenuEntete li a:hover,
    #MenuEntete li a:active {
        color: #FF4E11;
        box-shadow: 0 -0.625em 0 0 #FF4E11;
    }
    li#logo a:hover,
    li#logo a:active {
        box-shadow: 0 -0.625em 0 0 transparent;
    }
    /* Styles pour la rubrique en cours */
    nav #en-cours a {
        color: #FF4E11;
        box-shadow: 0 -0.625em 0 0 #FF4E11;
    }
    #MenuEntete li.large {
        width: 50%;
        text-align: left;
        padding-left: 0.938em;
    }
    #MenuEntete li.small {
        width: 13%;
    }
    #MenuEntete li.smallissime {
        width: 4.5%;
    }
    #nav {
        width: 100%;
        background-color: rgba(230, 230, 230, 0.9);
        margin: 0 auto;
        position: fixed;
        z-index: 9999;
    }
    #nav img {
        vertical-align: middle;
    }
}