body {
    padding: 0;
    margin: 0;
    background-color: whitesmoke;
}

.header_bar {
    background-color: green;
    width: 100%;
    color: whitesmoke;
    padding-bottom: 20px;
    padding-top: 20px;
    height: 30px;
}

.header_title {
    margin-top: auto;
    margin-bottom: auto;
    width: 25%;
    display: inline;
    font-size: 30px;
}

.header_link_list {
    list-style-type: none;
    margin: 0;
    padding: 0;
    width: 75%;
    display: inline;
}

.header_link_list li {
    display: inline-block;
}

.header_link_list a {
    text-decoration: none;
    color: inherit;
    background-color: darkgreen;
    padding: 10px;
}

.header_link_list a:hover {
    background-color: darkgray;
}