html,
body {
    height: 100%;
    margin: 0;
    overflow: hidden;
}

body {
    display: flex;
    flex-wrap: wrap;
    font-family: helvetica, arial, sans-serif;
    background: #EBF6F7;
}

.header-menu {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    width: 100%;
    height: 4vh;
    background: #4D8FAC;
    color: #fff;
}

h2 {
    margin: 0 0 0.3vh;
    color: #181B26;
}

aside {
    flex: 0.3;
    padding-left: 1vw;
    border-left: 1px solid #666;
    margin-top: 2vh;
}

section,
main {
    flex: 1;
    padding-right: 1vw;
    margin-left: 6vw;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

footer {
    display: flex;
    align-items: center;
    width: 100%;
    padding: 0 1.2vh;
    padding-left: 6vw;
    background: #C6C2B6;
    height: 3vh;
}

footer table td {
    width: 2.5vh;
    height: 2.5vh;
    padding: 0;
}

footer span.footer-label {
    font-size: 60%;
    color: #444;
    margin-left: 1em;
    font-style: italic;
}

a {
    text-decoration: none;
    color: #344D56;
}

a:hover {
    color: #C6C2B6;
}

.sidenav {
    height: 93vh;
    width: 4vw;
    position: fixed;
    z-index: 1;
    top: 4vh;
    left: 0;
    background-color: #181B26;
    overflow-x: hidden;
}

.categories {
    margin: 0;
    padding: 0;
    list-style: none;
    columns: 2;
    column-gap: 3vw;
}

.categories > li {
    break-inside: avoid;
    margin-bottom: 0.5vh;
}

.categories h3 {
    margin: 0 0 0.2vh;
    color: #4D8FAC;
}

.categories ol {
    margin: 0;
    padding-left: 1.5em;
}

.categories ol li {
    padding: 0.1vh 0;
}

.categories ol li .desc {
    color: #666;
    font-size: 70%;
    font-style: italic;
}

small {
    font-family: times, serif;
}

.skip-link {
    position: absolute;
    top: -100%;
    left: 0;
    background: #4D8FAC;
    color: #fff;
    padding: 0.5em 1em;
    z-index: 100;
    font-size: 14px;
}

.skip-link:focus {
    top: 0;
    color: #fff;
}

/* Responsive: hide sidebar on mobile */
@media (max-width: 600px) {
    .sidenav {
        display: none;
    }

    section,
    main {
        margin-left: 2vw;
    }

    footer {
        padding-left: 2vw;
    }

    .categories {
        columns: 1;
    }

    aside {
        display: none;
    }
}