default.css

:root {
	--main-font: Palatino, 'Palatino Linotype', 'Times New Roman', 'Droid Serif',
		Times, 'Source Serif Pro', serif, 'Apple Color Emoji', 'Segoe UI Emoji',
		'Segoe UI Symbol';
	--alt-font: 'helvetica neue', ubuntu, roboto, noto, 'segoe ui', arial,
		sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol';
	--code-font: Menlo, Consolas, monospace;
	--accent-color: black;
}

@page {
	size: A5 portrait;
	margin: 1cm 1cm 2cm;
}

html {
	font-size: 12pt;
	line-height: 1.3;
	font-family: var(--main-font);
	-webkit-print-color-adjust: exact;
	tab-size: 2;
}

h1,
h2,
h3,
h4,
h5,
h6 {
	margin-bottom: 0.5em;
	font-family: var(--alt-font);
	font-weight: bold;
	page-break-after: avoid;
	page-break-inside: avoid;
}

/*
	Prevent dangling headings at the end of the page.

	See:
	
	* https://github.com/danburzo/percollate/issues/110
	* https://stackoverflow.com/a/53742871/21613
 */
h1::after,
h2::after,
h3::after,
h4::after,
h5::after,
h6::after {
	content: '';
	display: block;
	height: 5rem;
	margin-bottom: -5rem;
}

a {
	color: inherit;
	text-decoration: underline;
}

/*
	Going on a limb here,
	but a.anchor in heading elements
	is most likely a '#' or '§' anchor
	we don't want to display in the PDF.
 */
h1 a.anchor,
h2 a.anchor,
h3 a.anchor,
h4 a.anchor,
h5 a.anchor,
h6 a.anchor {
	visibility: hidden;
	position: absolute;
}

th {
	font-family: var(--alt-font);
}

code,
pre {
	font-size: 0.85em;
}

pre code {
	font-size: 1em;
}

/*
	Don't display hidden elements
 */
[hidden],
[aria-hidden] {
	display: none;
}

/*
	Table of Contents page
	----------------------------------------------------
 */

.toc {
	page-break-before: always;
	page-break-after: always;
}

/*
	Article formatting
	----------------------------------------------------
 */

article {
	font-size: 1em;
	hyphens: auto;
}

article:not(:last-of-type) {
	page-break-after: always;
}

/*
	Article Header
	--------------
 */

.article__header {
	margin: 0 0 1.3em;
}

.article__title {
	font-size: 2.4em;
	margin: 0 0 0.25em;
	letter-spacing: -0.03em;
	line-height: 1.1;
}

.article__url {
	font-style: italic;
	font-size: 0.9em;
}

/*
	Article Content
	---------------
 */

.article__content img {
	max-width: 100%;
	display: block;
	margin: 0 auto;
}

.article__content figure {
	display: block;
	margin: 1.5em 0;
	padding: 0;
	text-align: center;
}

.article__content figcaption {
	font-size: 0.8em;
	font-family: var(--alt-font);
	margin: 0.81em 0;
	line-height: 1.625;
}

.article__content figure blockquote,
.article__content figure pre {
	text-align: left;
}

.article__content table,
.article__content figure {
	page-break-inside: avoid;
}

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

.article__content pre {
	border: 0.25pt solid #000;
	padding: 0.75em;
	font-size: 0.9em;
	white-space: pre-wrap;
	word-wrap: break-word;
}

.article__content kbd,
.article__content var,
.article__content samp {
	padding: 0 0.5em;
	box-shadow: 2pt 2pt 0 #ccc;
	border: 0.5pt solid #000;
	border-radius: 0.25em;
	font-size: 0.9em;
}

.article__content p {
	margin: 0;
	orphans: 3;
	widows: 3;
}

/*
	Indent all subsequent paragraphs.
 */
.article__content p + p {
	text-indent: 2em;
}

/*
	Fixes the text indent for images
	that get wrapped in a <p> tag
	by Readability.

	Reference:
	https://github.com/danburzo/percollate/issues/48
 */
.article__content p + p > img:only-child {
	margin-left: -2em;
}

.article__content hr {
	border: none;
	height: 0.5pt;
	margin: 1.3em 0;
	background: #000;
}

.article__content blockquote {
	font-size: 0.9em;
	line-height: 1.44;
	padding-left: 2em;
	border-left: 3pt solid #000;
	margin-left: 0;
}

.article__content table {
	width: 100%;
	border-collapse: collapse;
	page-break-inside: auto;
	font-size: 0.9em;
	line-height: 1.44;
	margin: 1.44em 0;
}

.article__content th {
}

.article__content th,
.article__content td {
	text-align: left;
	vertical-align: top;
	padding: 0.36em 1em 0.36em 0;
}

.article__content tr {
	border-bottom: 0.25pt solid #000;
	page-break-inside: avoid;
	page-break-after: auto;
}

.article__content dt {
	font-weight: bold;
}

.article__content ol,
.article__content ul {
	padding-left: 2em;
	list-style-position: outside;
	margin: 0.65em 0;
}

.article__content aside {
	font-family: var(--alt-font);
	font-size: 0.9em;
	line-height: 1.44;
	padding-left: 2em;
}

.article__content details {
	margin: 0.65em 0;
}

.article__content details > summary {
	font-weight: bold;
	font-size: 0.9em;
	font-family: var(--alt-font);
}

/*
	Page header / footer
	--------------------

	These are extracted when generating the PDF
	and are not subject to the page's CSS cascade.

	They're just placed here for easier style coordination
 */

.header-template {
}

.footer-template {
	font-size: 10pt;
	font-weight: bold;
}

/*
	Cover page
	----------
 */

.cover {
	color: var(--accent-color);
	border: 0.5em solid;
	font-family: var(--cover-font, var(--alt-font));
	padding: 2em;
}

.cover__author {
	margin: 1em 0;
	font-weight: bold;
}

.cover__title {
	font-size: 2.4em;
	margin: 0;
	line-height: 1.1;
}

.cover__subtitle {
	margin: 1em 0;
}

.cover__date {
	font-weight: bold;
}

/*
	Filetype specific
	-----------------
 */

.type--pdf body {
	margin: 0;
	padding: 0;
}

.type--pdf a:not(.no-href)::after {
	content: ' → ' attr(href) '';
	font-size: 0.8em;
	word-break: break-all;
	word-wrap: break-word;
	font-family: var(--alt-font);
}

.type--pdf .cover,
.type--epub .cover {
	position: absolute;
	overflow: hidden;
}

.type--pdf .cover {
	top: 0;
	left: 0;
	right: 0;
	bottom: 0;
}

.type--epub .cover {
	top: 2em;
	left: 2em;
	right: 2em;
	bottom: 2em;
}

.type--pdf .cover__content,
.type--epub .cover__content {
	position: absolute;
	top: 30%;
	left: 2em;
	right: 2em;
	transform: translate(0, -50%);
}

.type--pdf .cover__sentinel {
	page-break-after: always;
}