:root {
    --gutter: 1rem;
    --panel-padding: 1rem;
    --main-width: 80ch;
    --color-background-page: #f4f1ed;
    --background-image-tile: url("image/bats.gif");
    --color-text-primary: #363432;
    --color-text-secondary: #6c6054;
    --color-text-title: #264583;
    --color-background-panel: #dbd8d1;
    --color-border-highlight: #fafcf6;
    --color-border-shadow: #bcb4ac;
    --color-accent-primary: #456db0;
    --color-accent-secondary: #383127;
    --radius: 0;
}

*,
*::after,
*::before {
    box-sizing: border-box;
}

body,
html {
    height: 100%;
    margin: 0;
    font-family: Tahoma, Verdana, Arial, sans-serif;
    font-size: 15px;
    line-height: 1.5;
    color: var(--color-text-primary);
    background-color: var(--color-background-page);
    background-image: var(--background-image-tile);
    background-repeat: repeat;
    text-rendering: optimizeSpeed;
    -webkit-font-smoothing: none;
    image-rendering: pixelated;
}

html {
    min-height: 100%;
}

body {
    display: flex;
    flex-direction: column;
    align-items: center;
}

mark {
    background-color: var(--color-border-shadow);
    border-left: 4px solid var(--color-border-shadow);
    border-right: 4px solid var(--color-border-shadow);
    border-bottom: 2px solid var(--color-border-shadow);
}

.stage {
    flex: 1;
    width: 100%;
    min-height: 100vh;
    padding: calc(var(--gutter) * 1.5);
}

.skip-link {
    position: absolute;
    top: -9999px;
    left: 0;
    background: #000;
    color: #fff;
    padding: 0.5rem;
    z-index: 1000;
}

.skip-link:focus {
    top: var(--gutter);
    left: var(--gutter);
}

.threeD {
    border-top: 2px solid var(--color-border-highlight);
    border-left: 2px solid var(--color-border-highlight);
    border-right: 2px solid var(--color-border-shadow);
    border-bottom: 2px solid var(--color-border-shadow);
    background: var(--color-background-panel);
    border-radius: var(--radius);
}

.inset {
    border-top: 2px solid var(--color-border-shadow);
    border-left: 2px solid var(--color-border-shadow);
    border-right: 2px solid var(--color-border-highlight);
    border-bottom: 2px solid var(--color-border-highlight);
}

.titlebar {
    width: var(--main-width);
    margin: 1rem auto;
    padding: 1rem;
    background: var(--color-background-panel);
    color: var(--color-text-primary);
    text-align: center;
    border: 2px solid var(--color-border-shadow);
    border-top-color: var(--color-border-highlight);
    border-left-color: var(--color-border-highlight);
}

.site-title {
    font-size: 2rem;
    margin: 0;
    color: var(--color-text-title);
    font-variant: small-caps;
}

.site-description {
    margin: 0.25rem 0 0.75rem;
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

.navbar {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 0.5rem;
}

.navbar a {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    text-decoration: none;
    color: var(--color-text-primary);
    background: #e9e9e9;
    border-top: 2px solid var(--color-border-highlight);
    border-left: 2px solid var(--color-border-highlight);
    border-right: 2px solid var(--color-border-shadow);
    border-bottom: 2px solid var(--color-border-shadow);
    font-weight: bold;
    text-shadow: 0 1px var(--color-border-highlight);
}

.navbar a:hover {
    border-top: 2px solid var(--color-border-shadow);
    border-left: 2px solid var(--color-border-shadow);
    border-right: 2px solid var(--color-border-highlight);
    border-bottom: 2px solid var(--color-border-highlight);
    background: #e9e9e9;
    color: var(--color-text-primary);
}

.center {
    width: min(100%, calc(var(--main-width) + 2 * var(--gutter)));
    margin: 0 auto;
    position: relative;
}

.site-main {
    width: var(--main-width);
    margin: 0 auto;
    padding: 1rem;
    background: var(--color-background-panel);
    color: var(--color-text-primary);
    border-top: 2px solid var(--color-border-highlight);
    border-left: 2px solid var(--color-border-highlight);
    border-right: 2px solid var(--color-border-shadow);
    border-bottom: 2px solid var(--color-border-shadow);
    transition: opacity 0.2s ease;
}

.site-main h1,
.site-main h2,
.site-main h3 {
    color: var(--color-accent-secondary);
    font-weight: bold;
    border-bottom: 1px solid var(--color-border-shadow);
    margin-top: 1rem;
    padding-bottom: 0.25rem;
}

.site-main h4 {
    color: var(--color-accent-secondary);
    font-weight: bold;
    margin-top: 1rem;
}

.site-main p {
    margin-bottom: 1rem;
    color: var(--color-text-primary);
}

a {
    color: var(--color-accent-primary);
    text-decoration: underline;
    border: 1px solid var(--color-background-panel);
}

a:hover {
    color: var(--color-accent-secondary);
    text-decoration: none;
    border: 1px solid var(--color-accent-secondary);
}

.footer {
    width: var(--main-width);
    margin: 1rem auto;
    padding: 0.5rem;
    background: var(--color-background-panel);
    color: var(--color-text-primary);
    text-align: center;
    border: 2px solid var(--color-border-shadow);
    border-top-color: var(--color-border-highlight);
    border-left-color: var(--color-border-highlight);
}

.footer a {
    color: var(--color-accent-primary);
    text-decoration: none;
    border: none;
}

.footer a:hover {
    color: var(--color-accent-secondary);
    text-decoration: none;
    border: none;
}

.footer hr {
    border: none;
    border-top: 1px solid var(--color-border-shadow);
    margin: 0.75rem 0;
}

.box {
    padding: 0.5rem;
    background: var(--color-background-panel);
    border-top: 2px solid var(--color-border-highlight);
    border-left: 2px solid var(--color-border-highlight);
    border-right: 2px solid var(--color-border-shadow);
    border-bottom: 2px solid var(--color-border-shadow);
    margin-bottom: 1rem;
}

code,
pre {
    font-family: "Courier New", Courier, monospace;
    background: #f0f0f0;
    border: 2px inset var(--color-border-shadow);
    padding: 0.25rem 0.5rem;
    color: #111111;
    display: inline-block;
}

table {
    border-collapse: collapse;
    width: auto;
    margin: 1em auto;
    border-top: 1px solid var(--color-text-primary);
    border-bottom: 1px solid var(--color-text-primary);
}

table caption {
    caption-side: top;
    text-align: center;
    padding-bottom: 0.8em;
}

table th {
    padding: 0.2em 1.0em;
    border-top: 1px solid var(--color-text-primary);
    border-bottom: 1px solid var(--color-text-primary);
}

table td {
    vertical-align: middle;
}

@media (max-width: 960px) {
    .footer,
    .site-main,
    .titlebar {
        width: 100%;
    }
}

@media print {
    body {
        background: #fff;
        color: #000;
    }
    .navbar {
        display: none;
    }
    .site-main {
        border: none;
    }
}