.navigation-bar {
    padding-bottom: 10px;
    border-bottom: 1px solid gray;
}

.navigation-bar a {
    margin-right: 25px;
} 

.main-content {
    padding-top: 10px;
    padding-bottom: 10px;
}

footer {
    padding-top: 10px;
    border-top: 1px solid gray;
    text-align: center;
}

body {
    max-width: 700px;
    margin-right: auto;
    padding-left: 10px;
    padding-right: 10px;
}