body {
    margin-left: 30%;
    margin-right: 30%;
}

.header_img {
    display: block;
    margin-left: auto;
    margin-right: auto;
    width: 65%;
}

nav {
    background-color: #000000;
    display: block;
}

nav a {
    margin-left: 5px;
    color: white;
    font-weight: bold;
}

nav a:visited {
    color: white;
}

nav a:hover {
    background-color: white;
    color: black;
}

.navbar {
    overflow: hidden;
}


.navbar-right {
    float:right;
}

.art_sbar {
    border-width: 1px;
    border-left-style: dashed;
}

.art_bbar {
    border-width: 1px;
    border-bottom-style:dashed;
}

article {
    margin-left: 10px;
    margin-bottom: 10px;
}

footer{
    bottom: 0;
    position: fixed;
    width: 40%;
}

.footer {
    background-color: black;
    color: white;
}