html
{
    font-family: sans-serif;
}

body
{
    margin: 0;
    display: flex;
    flex-direction: column;
    height: 100vh;
}

pre
{
    padding: 12px 16px;
    font-size: 14px;
    border: 1px solid lightgrey;
    background-color: whitesmoke;
}

span.code
{
    font-family: Courier New, sans-serif;
    background-color: whitesmoke;
}

a:link, a:visited
{
    text-decoration: none;
    color: slategray;
}

a:focus, a:hover, a:active
{
    text-decoration: none;
    color: lightslategrey;
}

header
{
    display: flex;
    flex-direction: row;
    width: 100%;
    border-bottom: 1px solid lightgray;
}

header > #banner
{
    text-align: right;
    width: 25%;
    padding: 12px 16px;
}

header > #banner > a
{
    text-decoration: none;
}

header > #menu
{
    width: 75%;
    height: 100%;
}

#menu > ul
{
    display: flex;
    flex-direction: row;
    height: 100%;
}

#menu > ul > li
{
    align-content: center;
    list-style-type: none;
}

#center
{
    flex-grow: 1;
    display: flex;
    flex-direction: row;
}

#center > nav
{
    display: flex;
    flex-direction: row;
    padding: 12px 16px;
    width: 25%;
}

#center > nav > #nav-margin
{
    flex-grow: 1;
}

#center > nav > ul > li
{
    list-style-type: none;
    margin: 0 0 12px 0;
    font-weight: bold;
}

#center > nav > ul > li > ul
{
    list-style-type: none;
}

#center > nav > ul > li > ul > li
{
    font-weight: normal;
    color: lightslategrey;
}

section
{
    padding: 12px 16px;
    flex-grow: 1;
    width: 75%;
    border-left: 1px solid lightgray;
}

footer
{
    padding: 12px 16px;
    text-align: center;
    border-top: 1px solid lightgray;
}