:root {
	--light-fg-color: black;
	--light-bg-color: white;
	--light-outer-shadow-color: #BBBBBB;
	--light-outer-bg-color: #E4E4E4;
	--light-alt-bg-color: #FFFFD0;
	--light-field-hover-bg-color: #F0F0F0;
	--light-field-active-bg-color: #E0E0E0;
	--light-link-idle-color: blue;
	
	--dark-fg-color: white;
	--dark-bg-color: #202020;
	--dark-outer-shadow-color: #000000;
	--dark-outer-bg-color: black;
	--dark-alt-bg-color: #101010;
	--dark-field-hover-bg-color: #000000;
	--dark-field-active-bg-color: #404040;
	--dark-link-idle-color: lightblue;
}

:root {
	color-scheme: light dark;

	--nav-fg-color: white;
	--nav-bg-color: darkred;
	--nav-bg-color-selected: #C00000;
	--sep-color: gray;
}

/* Vím, že by se dalo použít light-dark(...). Ale to funguje jen v nejnovějších prohlížečích. */
@media (prefers-color-scheme: light) {
	:root {
		--fg-color: var(--light-fg-color);
		--bg-color: var(--light-bg-color);
		--outer-shadow-color: var(--light-outer-shadow-color);
		--outer-bg-color: var(--light-outer-bg-color);
		--alt-bg-color: var(--light-alt-bg-color);
		--field-hover-bg-color: var(--light-field-hover-bg-color);
		--field-active-bg-color: var(--light-field-active-bg-color);
		--link-idle-color: var(--light-link-idle-color);

		--theme-switch-icon: var(--light-theme-switch-icon);
		--narrow-layout-switch-icon: var(--light-narrow-layout-switch-icon);
		--wide-layout-switch-icon: var(--light-wide-layout-switch-icon);
		--fg-gnu-head: var(--dark-gnu-head);
		--bg-gnu-head: var(--light-gnu-head);
	}

	[data-color-scheme="invert"] {
		--fg-color: var(--dark-fg-color);
		--bg-color: var(--dark-bg-color);
		--outer-shadow-color: var(--dark-outer-shadow-color);
		--outer-bg-color: var(--dark-outer-bg-color);
		--alt-bg-color: var(--dark-alt-bg-color);
		--field-hover-bg-color: var(--dark-field-hover-bg-color);
		--field-active-bg-color: var(--dark-field-active-bg-color);
		--link-idle-color: var(--dark-link-idle-color);

		--theme-switch-icon: var(--dark-theme-switch-icon);
		--narrow-layout-switch-icon: var(--dark-narrow-layout-switch-icon);
		--wide-layout-switch-icon: var(--dark-wide-layout-switch-icon);
		--fg-gnu-head: var(--light-gnu-head);
		--bg-gnu-head: var(--dark-gnu-head);
	}
}

@media (prefers-color-scheme: dark) {
	:root {
		--fg-color: var(--dark-fg-color);
		--bg-color: var(--dark-bg-color);
		--outer-shadow-color: var(--dark-outer-shadow-color);
		--outer-bg-color: var(--dark-outer-bg-color);
		--alt-bg-color: var(--dark-alt-bg-color);
		--field-hover-bg-color: var(--dark-field-hover-bg-color);
		--field-active-bg-color: var(--dark-field-active-bg-color);
		--link-idle-color: var(--dark-link-idle-color);

		--theme-switch-icon: var(--dark-theme-switch-icon);
		--narrow-layout-switch-icon: var(--dark-narrow-layout-switch-icon);
		--wide-layout-switch-icon: var(--dark-wide-layout-switch-icon);
		--fg-gnu-head: var(--light-gnu-head);
		--bg-gnu-head: var(--dark-gnu-head);
	}
	
	[data-color-scheme="invert"] {
		--fg-color: var(--light-fg-color);
		--bg-color: var(--light-bg-color);
		--outer-shadow-color: var(--light-outer-shadow-color);
		--outer-bg-color: var(--light-outer-bg-color);
		--alt-bg-color: var(--light-alt-bg-color);
		--field-hover-bg-color: var(--light-field-hover-bg-color);
		--field-active-bg-color: var(--light-field-active-bg-color);
		--link-idle-color: var(--light-link-idle-color);

		--theme-switch-icon: var(--light-theme-switch-icon);
		--narrow-layout-switch-icon: var(--light-narrow-layout-switch-icon);
		--wide-layout-switch-icon: var(--light-wide-layout-switch-icon);
		--fg-gnu-head: var(--dark-gnu-head);
		--bg-gnu-head: var(--light-gnu-head);
	}
}

:root {
	--layout-switch-icon: var(--narrow-layout-switch-icon);
}

[data-layout="wide"] {
	--layout-switch-icon: var(--wide-layout-switch-icon)
}

html {
	margin: 0;
	background-color: var(--outer-bg-color);
	min-height: calc(100% - 32px);
}

body {
	font-family: "Noto Sans", sans-serif; /* Svobodný font. */
	font-size: 16px;
	display: flex;
	flex-direction: column;
	color: var(--fg-color);
	background-color: var(--bg-color);
}

header {
	padding: calc(16px - 8px) 16px;
	position: relative;
	background-color: var(--bg-color);
}

.light-dark-switch {
	position: absolute;
	top: 16px;
	right: 16px;
	cursor: pointer;
	content: var(--theme-switch-icon);
	width: 20px;
}

.layout-switch {
	position: absolute;
	top: 48px;
	right: 16px;
	cursor: pointer;
	content: var(--layout-switch-icon);
	width: 20px;
}

a {
	color: var(--link-idle-color);
}

header * {
	margin: 8px 0;
}

.header-title {
	font-size: 32px;
}

.header-subtitle {
	font-size: 24px;
}

.full-width {
	width: 100%;
}

.img-text-container {
	position: relative;
}

.img-text {
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	display: flex;
	justify-content: center;
	align-items: center;
	opacity: 100%;
	color: var(--fg-color);
	z-index: 1;
	pointer-events: none;
}

.countdown {
	font-family: monospace;
	font-weight: bold;
	font-size: 48px;
	text-align: center;
}

.countdown-bg {
	opacity: 40%;
	z-index: 0;
}

nav {
	background-color: var(--nav-bg-color);
	color: var(--nav-fg-color);
	user-select: none;
}

main {
	flex-grow: 1;
	padding: 16px;
}

.gnu-head {
	content: var(--fg-gnu-head);
}

footer {
	border-top: 2px solid var(--sep-color);
	padding: calc(16px - 8px) 16px;
	text-align: center;
}

footer>* {
	margin: 8px 0;
}

h1 {
	font-size: 32px;
}

h2 {
	font-size: 26px;
}

h3 {
	font-size: 20px;
}

table {
	border-spacing: 0;
	border: 1px solid var(--sep-color);
}

th, td {
	background-color: var(--alt-bg-color);
	border: 1px solid var(--sep-color);
	padding: 4px;
}

ul li {
	margin: 8px 0;
}

ol li {
	margin: 8px 0;
}

@media (width >= 500px) {
	figure.aside {
		width: 200px;
		margin: 0 0 16px 16px;
		float: right;
	}

	/* Jinak to neudělá nic. */
}

figure img,svg,inserted-svg {
	width: 100%;
	height: auto;
}

figcaption {
	font-style: italic;
}

nav ul {
	width: 100%;
	height: 100%;
	display: flex;
	flex-direction: row;
	margin: 0;
	padding: 0;
	list-style-type: none;
}

@media (width < 750px) {
	nav ul {
		flex-direction: column;
	}
}

nav ul li {
	flex-grow: 1;
	flex-basis: 0;
	display: flex;
	margin: 0;
}

nav ul li a {
	display: flex;
	flex-direction: column;
	justify-content: center;
	
	flex-grow: 1;
	padding: 8px 16px;

	text-align: center;
	text-decoration: none;
	color: var(--nav-fg-color);

	transition: background-color .3s;
}

nav ul li a:hover {
	background-color: var(--nav-bg-color-selected);
	color: var(--nav-fg-color);
}

nav ul li a:active {
	color: var(--nav-fg-color);
}

nav ul li a:visited {
	color: var(--nav-fg-color);
}

@media (width >= 900px) {
	html:not([data-layout="wide"]) {
		padding: 16px 0;
	}

	:not([data-layout="wide"]) body {
		margin: 0 auto;
		max-width: 800px;
		box-shadow: 0 0 5px 5px var(--outer-shadow-color);
	}
	
	[data-layout="wide"] body {
		margin: 0;
	}
}

@media (width < 900px) {
	body {
		margin: 0;
	}
	.img-text {
		position: relative;
		margin-bottom: 32px;
	}
	.layout-switch {
		display: none;
	}
}

@media print {
	.light-dark-switch {
		display: none;
	}
	.layout-switch {
		display: none;
	}
	nav {
		display: none;
	}
}