/* subsystem.co. Tokens are composed from static/themes; nothing below names a colour. */

:root, [data-theme="dark"] {
	color-scheme: dark;
	--page: #0A0A0B;
	--surface: #141313;
	--raised: #1D1C1A;
	--sunken: #1D1C1A;
	--head-ground: #262421;
	--code-inline: #1D1C1A;
	--rule: #302D29;
	--rule-strong: #807A70;
	--focus: #7FB0EC;
	--ink: #F2EFE6;
	--ink-body: #E3E0D7;
	--ink-quiet: #A9A399;
	--ink-faint: #7C766D;
	--link: #7FB0EC;
	--link-visited: #5A87BE;
	--zebra: #101010;
	--select-ground: #1F3A5C;
	--target-ground: #3A3113;
	--syn-text: #D6D2C8;
	--syn-comment: #BCB5A6;
	--syn-keyword: #EFE0BC;
	--syn-string: #E8A247;
	--syn-name: #7FB0EC;
	--syn-number: #6FD08A;
	--syn-meta: #9A948A;
	--syn-error: #F07070;
	--syn-linenum: #969086;
	--syn-emph-ground: #262420;
	--syn-add-ground: #1B2A1E;
	--syn-del-ground: #2A1C1B;
}

[data-theme="light"] {
	color-scheme: light;
	--page: #F7F5F0;
	--surface: #EDEAE2;
	--raised: #FFFFFF;
	--sunken: #060606;
	--head-ground: #E2DED4;
	--code-inline: #EDEAE2;
	--rule: #DCD7CB;
	--rule-strong: #767065;
	--focus: #1F5AA8;
	--ink: #17140D;
	--ink-body: #231F18;
	--ink-quiet: #5C564A;
	--ink-faint: #7C766D;
	--link: #1F5AA8;
	--link-visited: #0E3466;
	--zebra: #F1EEE7;
	--select-ground: #CBDCF2;
	--target-ground: #F6E7B0;
	--syn-text: #D6D2C8;
	--syn-comment: #BCB5A6;
	--syn-keyword: #EFE0BC;
	--syn-string: #E8A247;
	--syn-name: #7FB0EC;
	--syn-number: #6FD08A;
	--syn-meta: #9A948A;
	--syn-error: #F07070;
	--syn-linenum: #969086;
	--syn-emph-ground: #1C1A15;
	--syn-add-ground: #0B1A0E;
	--syn-del-ground: #1C0B0B;
}

@media (prefers-color-scheme: light) {
	:root:not([data-theme]) {
		color-scheme: light;
		--page: #F7F5F0;
		--surface: #EDEAE2;
		--raised: #FFFFFF;
		--sunken: #060606;
		--head-ground: #E2DED4;
		--code-inline: #EDEAE2;
		--rule: #DCD7CB;
		--rule-strong: #767065;
		--focus: #1F5AA8;
		--ink: #17140D;
		--ink-body: #231F18;
		--ink-quiet: #5C564A;
		--ink-faint: #7C766D;
		--link: #1F5AA8;
		--link-visited: #0E3466;
		--zebra: #F1EEE7;
		--select-ground: #CBDCF2;
		--target-ground: #F6E7B0;
		--syn-text: #D6D2C8;
		--syn-comment: #BCB5A6;
		--syn-keyword: #EFE0BC;
		--syn-string: #E8A247;
		--syn-name: #7FB0EC;
		--syn-number: #6FD08A;
		--syn-meta: #9A948A;
		--syn-error: #F07070;
		--syn-linenum: #969086;
		--syn-emph-ground: #1C1A15;
		--syn-add-ground: #0B1A0E;
		--syn-del-ground: #1C0B0B;
	}
}

/* Layout and type. Every colour is a token from static/themes; naming one here fails the build. */

@font-face {
	font-family: "IBM Plex Mono";
	src: url("/s/fonts/ibm-plex-mono-latin-400-normal.08949f728d.woff2") format("woff2");
	font-weight: 400;
	font-style: normal;
	font-display: swap;
}

@font-face {
	font-family: "IBM Plex Mono";
	src: url("/s/fonts/ibm-plex-mono-latin-400-italic.0840095faa.woff2") format("woff2");
	font-weight: 400;
	font-style: italic;
	font-display: swap;
}

@font-face {
	font-family: "IBM Plex Mono";
	src: url("/s/fonts/ibm-plex-mono-latin-600-normal.0d1f0b8d07.woff2") format("woff2");
	font-weight: 600;
	font-style: normal;
	font-display: swap;
}

:root {
	--sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
	--mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;
	--measure: 70ch;
	--space-1: 0.25rem;
	--space-2: 0.5rem;
	--space-3: 0.75rem;
	--space-4: 1rem;
	--space-6: 1.5rem;
	--space-8: 2rem;
	--space-12: 3rem;
}

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

html {
	background-color: var(--page);
	color: var(--ink-body);
	font-family: var(--sans);
	-webkit-text-size-adjust: 100%;
	text-size-adjust: 100%;
}

body {
	margin: 0;
	font-size: 1rem;
	line-height: 1.62;
}

::selection {
	background-color: var(--select-ground);
	color: var(--ink);
}


/* Links. Always underlined, so colour is never the only sign; hover thickens the line. */

a {
	color: var(--link);
	text-decoration-line: underline;
	text-decoration-thickness: 1px;
	text-underline-offset: 0.18em;
}

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

a:hover {
	text-decoration-thickness: 2px;
}

/* A visited link is never drawn on the target ground: no ground that dark stays visible. */
:target a,
:target a:visited {
	color: var(--link);
}

/* The focus ring is the link blue, so its offset and thickness carry what colour cannot. */
:focus-visible {
	outline: 2px solid var(--focus);
	outline-offset: 3px;
	border-radius: 2px;
}

.skip {
	position: absolute;
	left: -9999px;
}

.skip:focus {
	left: var(--space-4);
	top: var(--space-4);
	z-index: 10;
	padding: var(--space-2) var(--space-4);
	background-color: var(--raised);
	color: var(--ink);
}


/* Masthead */

.masthead {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: var(--space-3) var(--space-8);
	padding: var(--space-4) var(--space-6);
	background-color: var(--surface);
	border-bottom: 1px solid var(--rule);
}

.wordmark,
.wordmark:visited {
	color: var(--ink);
	font-weight: 600;
	letter-spacing: 0.02em;
	text-decoration: none;
}

.apps ul {
	display: flex;
	flex-wrap: wrap;
	gap: var(--space-2) var(--space-6);
	margin: 0;
	padding: 0;
	list-style: none;
}

.apps a,
.apps a:visited,
.sidebar a,
.sidebar a:visited {
	color: var(--ink-quiet);
	text-decoration: none;
}

.apps a:hover,
.sidebar a:hover {
	color: var(--ink);
	text-decoration: underline;
}

.apps a[aria-current="page"],
.sidebar a[aria-current="page"] {
	color: var(--ink);
	text-decoration: underline;
	text-decoration-color: var(--link);
	text-decoration-thickness: 2px;
}

.theme-slot {
	margin-left: auto;
}

.theme-toggle {
	padding: var(--space-1) var(--space-3);
	border: 1px solid var(--rule-strong);
	border-radius: 4px;
	background-color: transparent;
	color: var(--ink-quiet);
	font: inherit;
	font-size: 0.875rem;
	cursor: pointer;
}

.theme-toggle:hover {
	color: var(--ink);
}


/* Page layout */

.layout {
	display: grid;
	grid-template-columns: minmax(10rem, 15rem) minmax(0, 1fr);
	gap: var(--space-12);
	max-width: 76rem;
	margin: 0 auto;
	padding: var(--space-8) var(--space-6);
}

.sidebar ul {
	position: sticky;
	top: var(--space-6);
	display: grid;
	gap: var(--space-2);
	margin: 0;
	padding: 0;
	list-style: none;
	font-size: 0.9375rem;
	line-height: 1.4;
}

@media (max-width: 52rem) {

	.layout {
		grid-template-columns: minmax(0, 1fr);
		gap: var(--space-6);
		padding: var(--space-6) var(--space-4);
	}

	.sidebar ul {
		position: static;
		display: flex;
		flex-wrap: wrap;
		gap: var(--space-2) var(--space-6);
	}
}


/* Prose. Siblings are spaced by gap, so a block dropped in never doubles a margin. */

.prose {
	display: flex;
	flex-direction: column;
	gap: var(--space-4);
	min-width: 0;
	max-width: var(--measure);
}

.prose > * {
	margin: 0;
}

.prose h1,
.prose h2,
.prose h3,
.prose h4 {
	color: var(--ink);
	font-weight: 600;
	line-height: 1.25;
	text-wrap: balance;
}

.prose h1 {
	font-size: 2.125rem;
}

.prose h2 {
	margin-top: var(--space-6);
	padding-top: var(--space-4);
	border-top: 1px solid var(--rule);
	font-size: 1.375rem;
}

.prose h3 {
	margin-top: var(--space-2);
	font-size: 1.0625rem;
}

.prose h4 {
	font-size: 1rem;
}

.prose :target {
	background-color: var(--target-ground);
}

.prose ul,
.prose ol {
	padding-left: 1.5rem;
}

.prose li + li {
	margin-top: var(--space-1);
}

.prose blockquote {
	padding: var(--space-3) var(--space-4);
	border-left: 3px solid var(--rule-strong);
	background-color: var(--surface);
}

.prose blockquote > * {
	margin: 0;
}

.prose blockquote > * + * {
	margin-top: var(--space-3);
}

.prose hr {
	width: 100%;
	border: 0;
	border-top: 1px solid var(--rule);
}

.prose sub {
	color: var(--ink-quiet);
	font-size: 0.8125rem;
	line-height: 1.5;
	vertical-align: baseline;
}


/* Code */

code,
pre {
	font-family: var(--mono);
}

:not(pre) > code {
	padding: 0.1em 0.35em;
	border-radius: 3px;
	background-color: var(--code-inline);
	color: var(--ink);
	font-size: 0.875em;
}

a > code {
	color: inherit;
}

.prose pre.code {
	padding: var(--space-4);
	overflow-x: auto;
	border-radius: 6px;
	background-color: var(--sunken);
	color: var(--syn-text);
	font-size: 0.875rem;
	line-height: 1.55;
	tab-size: 4;
}


/* Tables. Wide ones scroll inside their own box rather than widening the page. */

.table-scroll {
	max-width: 100%;
	overflow-x: auto;
}

.prose table {
	border-collapse: collapse;
	font-size: 0.9375rem;
	line-height: 1.5;
	font-variant-numeric: tabular-nums;
}

.prose th,
.prose td {
	padding: var(--space-2) var(--space-3);
	border-bottom: 1px solid var(--rule);
	text-align: left;
	vertical-align: top;
}

.prose th {
	border-bottom-color: var(--rule-strong);
	background-color: var(--head-ground);
	color: var(--ink);
	font-weight: 600;
}

.prose tbody tr:nth-child(even) {
	background-color: var(--zebra);
}

.prose .align-left {
	text-align: left;
}

.prose .align-center {
	text-align: center;
}

.prose .align-right {
	text-align: right;
}


/* Where a page came from */

.page-source {
	margin-top: var(--space-8);
	padding-top: var(--space-4);
	border-top: 1px solid var(--rule);
	color: var(--ink-quiet);
	font-size: 0.875rem;
}


/* Home */

.home {
	max-width: 76rem;
	margin: 0 auto;
	padding: var(--space-12) var(--space-6);
}

.home h1 {
	margin: 0 0 var(--space-8);
	color: var(--ink);
	font-size: 2.125rem;
	line-height: 1.25;
}

.app-list {
	display: grid;
	grid-template-columns: repeat(auto-fill, minmax(16rem, 1fr));
	gap: var(--space-4);
	margin: 0;
	padding: 0;
	list-style: none;
}

.app-list li {
	padding: var(--space-4) var(--space-6);
	border: 1px solid var(--rule);
	border-radius: 6px;
	background-color: var(--raised);
}

.app-list a {
	font-size: 1.0625rem;
	font-weight: 600;
}

.app-list p {
	margin: var(--space-2) 0 0;
	color: var(--ink-quiet);
}

.code .syn-comment { color: var(--syn-comment); }
.code .syn-keyword { color: var(--syn-keyword); }
.code .syn-string { color: var(--syn-string); }
.code .syn-name { color: var(--syn-name); }
.code .syn-number { color: var(--syn-number); }
.code .syn-meta { color: var(--syn-meta); }
.code .syn-error { color: var(--syn-error); }
.code .syn-comment { font-style: italic; }
.code .syn-keyword { font-weight: 600; }