.jumbotron{
    text-align: center;
    font-family: sans-serif;
}

ul {
    list-style-type: none;
    margin: 0px;
    padding: 0px;
    overflow: hidden;
    background-color: #333;

}

li {
    float: left;
}

li a {
    display: block;
    color: white;
    text-align: center;
    padding: 14px 16px;
    font-family: sans-serif;
    text-decoration: none;
}

li a:hover {
    background-color: #111;
} 

.form_group {
    font-family: sans-serif;
    padding: 5px;
}