body {
    margin: 0;
    font-family: Arial;
    background-image: url("../img/wallpaper.png");
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-position: center;
    background-size: cover;
    height: 100%;
}

/* TOP NAV */

header {
    background-color: #373737;
}

.topnav {
    overflow: hidden;
}

.topnav form {
    display: none;
    float: right;
    padding-top: 40px;
    padding-right: 20px;
}

#messagebvn {
    float: right;
    padding-top: 40px;
    padding-right: 50px;
    font-size: larger;
    color: #f2f2f2;
}



.principal {
    margin-left: 10%;
    margin-right: 10%;
    padding-top: 0.01%;
    padding-left: 15px;
    padding-right: 15px;
    color: rgb(244, 244, 244);
    text-shadow: 0 0 1px transparent;
    line-height: 24px;
    text-align: justify;
    font-size: large;
    background-color: #777777df;
    min-height: 89.5vh;
}

.topnav a {
    float: left;
    display: block;
    color: #f2f2f2;
    font-size: 17px;
    text-align: center;
    padding: 14px 16px;
    text-decoration: none;
}

.topnav a:hover {
    background-color: #ddd;
    color: black;
}

.topnav .icon {
    display: none;
}

@media screen and (max-width: 600px) {

    .topnav a:not(:first-child),
    .dropdown .dropbtn {
        display: none;
    }

    .topnav a.icon {
        float: right;
        display: block;
    }
}

@media screen and (max-width: 600px) {
    .topnav.responsive {
        position: relative;
    }

    .topnav.responsive .icon {
        position: absolute;
        right: 0;
        top: 0;
    }

    .topnav.responsive a {
        float: none;
        display: block;
        text-align: left;
    }

    .topnav.responsive .dropdown {
        float: none;
    }

    .topnav.responsive .dropdown-content {
        position: relative;
    }

    .topnav.responsive .dropdown .dropbtn {
        display: block;
        width: 100%;
        text-align: left;
    }
}

#contenu {
    display: flex;
    flex-wrap: wrap;
}

#contenu img {
    width: 100%;
}

.jeu {
    flex: 0 0 23%;
    margin: 10px;
}

.jeu titre {
    text-decoration: underline;
}

.jeu prix {
    font-weight: bold;
}