/* CSS that adds the bare minimum for a simple, accessible,
 * touch-friendly layout.
 * Nothing here exists purely for aesthetics; everything addresses a
 * specific a11y, compatibility, or critical
 * usability need.
 *
 * One exception: I re-set the input styles so Safari wouldn't make them
 * pill-shaped.
 *
 * I also don't use any classes except for image presentation. (e.g. to
 * specify that an image should have pixelated rendering or be inverted
 * in dark mode).
 * My HTML contains microformats2 classnames for IndieWeb parsers, but I
 * don't actually use those for styling.
 *
 * To keep myself from caring about minute details, I limited myself to
 * only defining spacing in increments of .25em. Pixels are 1px or
 * multiples of 3px. This also improves compression. No more "finding
 * the perfect value".
 *
 * I cite WCAG 2.2 success criteria with "SC". I also tried to meet
 * the Google a11y requirement of 48px tap targets separated by atl
 * 8px, excluding inline links. This involved increasing font size,
 * padding, line-height, and margins. */

html {
	/* Mobile screens benefit from greater line-spacing so links are
	 * further apart. Dyslexic users prefer the spacing too.
	 * Necessary to meet SC 1.4.8.
	 * <100dpi screens: sans-serif is better. Why did browsers settle
	 * on serif being the default?? */
	font: 100%/1.5 sans-serif;
	/* Nearly every page on my site is taller than the viewport.
	 * Paint the scrollbar ASAP to prevent layout shifts. */
	overflow-y: scroll;
}

/* This should not take effect on printouts, to save paper. */
@media screen {
	body {
		/* Default font sizes are one-size-fits-all; they're optimized for a
		 * wide variety of complex pages. For single-column websites like
		 * mine, it's ideal to bump it up ever so slightly. This also makes
		 * <sup>, <sub>, <small>, etc. large enough to have decent contrast
		 * with minimal adjustment, and makes tap-targets larger.
		 * Only do this on screen, since printouts already improve legibility
		 * and cost paper + ink.
		 * 108.75% is the minimum required to get superscripts to reach 14.5
		 * CSS pixels with most default stylesheets. At that size, my dark
		 * color palette has sufficient contrast.*/
		font-size: 108.75%;

		/* Aligning to the center with space on both sides prevents accidental
		* link activation on tablets, and is a common practice that users are
		* more used to for articles. */
		margin: auto;

		/* WCAG recommends a max line width. Not everyone can resize the
		 * viewport. This isn't for large blocks of text yet, so we don't have
		 * to go by SC 1.4.8.
		 * 45em = lowest acceptable width for titles, nav, footers, etc */
		max-width: 45em;

		/* Phone cases can cover the edges. Swipe-from-edge navigations
		 * should not conflict with the page elements. Focus outlines for
		 * heavily-padded nav links should not be cut-off. All three concerns
		 * are addressed by adding some body padding.
		 * I followed Google's a11y recommendations of "at least 8px space
		 * between tappables" by creating margins/paddings between nav links;
		 * re-use that same amount of space here. 24px is what it takes to
		 * create atl 48px of non-interactive space on <ul> and <ol> elements
		 * containing lists of interactives, with 8px in between.
		 * Don't use relative units here; this margin shouldn't scale with
		 * zoom, or else text will get narrower with zoom. */
		padding: 0 24px;
	}

	/* 45em is too wide for long body text.
	 * Typically meets SC 1.4.8, plus or minus a few characters. */
	div[itemprop="articleBody"] {
		margin: auto;
		max-width: 35em;
	}

	summary {
		/* It's not obvious that a <summary> has button semantics.
		 * "cursor: pointer" is used on MDN, web.dev, GitHub, gov.uk, and
		 * others so it's not "novel" and won't surprise users. */
		cursor: pointer;
	}

	/* If we have a list of disclosure widgets, we need some
	 * non-interactive space on the screen that's safe to tap. */
	form,
	li details {
		margin: .5em 0;
	}

	/* Make superscripts a bit easier to tap. */
	sup > a {
		margin-left: .25em;
		padding-bottom: .25em;
	}

	/* SC 2.5.5, Google a11y: Increase tap target size a bit
	 * - Summary is a tappable button
	 * - standalone links in lists are usually parts of collections of
	 *   links that should be easy to fat-finger
	 * - links that directly follow h2 without being contained in a
	 *   paragraph are section permalinks. */

	input,
	div[itemprop="comment"] dd > a,
	dt > a,
	summary,
	nav[itemprop="breadcrumb"] a,
	nav[itemprop="breadcrumb"] > span,
	aside > a, /* Used for section permalinks */
	li > a {
		padding: .75em .25em;
	}

	/* Compensate for misalignment and wasted space caused by padding
	 * and margin adjustments in nav children made to meet SC 2.5.5
	 * Also prevent overlapping outlines on focus */

	/* We've increased the padding for dt > a, but dt without a link
	 * should take up as much space. */
	dt {
		margin: .75em 0;
	}

	dt > a {
		margin: -.75em 0 -.75em -.25em;
		display: inline-block;
	}

	/* <dt> should not be closer to the previous <dd> than the following <dd>.
	 * That can happen in webmentions. */
	dd {
		padding-bottom: .25em;
	}

	aside > a {
		margin: -.75em -.25em;
	}

	header a[href="#main"],
	div[itemprop="comment"] dd > a ,
	footer > nav,
	/* List items with direct hyperlink children should only have one hyperlink. */
	li > a,
	aside > a,
	nav ol a {
		margin-left: -.25em;
		display: inline-block;
	}

	/* The nav has to be distant-enough from the top to make room for a skip-link. */
	header > nav {
		margin: .75em 0 0 -.25em;
		display: block;
	}

	/* Multiple consecutive <dt> that share a <dd> shouldn't have tap targets overlap */
	dt + dt > a {
		padding-top: 0;
	}

	nav:not([itemprop="breadcrumb"]) li,
	ol li > a {
		margin: .25em;
	}

	/* Increase backlink tap target size */
	a[role="doc-backlink"] {
		padding: 0 1.75em 1.5em .25em;
	}

	/* Make room for those big backlink buttons so they don't overlap
	 * with links on the following endnote */
	section[role="doc-endnotes"] li {
		margin-bottom: 1.75em;
	}

	header a[href="#main"] {
		position: absolute;
		top: -2em;
		padding: 0 .25em;
	}

	header a[href="#main"]:focus {
		top: 0;
	}
}

/* narrow screens: reduce list indentation, hyphenate nested lists
 * touch screens: lists of links should be easy to tap so give them
 * some spacing (partial SC 2.5.5). There should be non-interactive
 * space to the left that's safe to tap. */
dd,
ol,
ul {
	margin: 0;
	padding-left: 1.5em;
}

blockquote,
ol ol,
ul ul {
	-webkit-hyphens: auto;
	hyphens: auto;
	margin: 0;
	padding-left: 1em;
}

/* Save some space and paper by making the site nav and footer links
 * single-line without bullets. The title should be visible in the fold
 * on most screens so users can identify the current page. */

/* Step 1 to making the single-line nav: remove the bullet padding. */
nav ul {
	padding: 0;
}

/* Make breadcrumbs inline, so they look familiar. */
nav[itemprop="breadcrumb"] ol,
nav[itemprop="breadcrumb"] li,
nav[itemprop="breadcrumb"] > span {
	display: inline-block;
}

nav[itemprop="breadcrumb"] ol {
	margin: -.25em 0;
	padding: 0;
}

nav[itemprop="breadcrumb"] li:not(:last-of-type)::after {
	content: "→";
}

/* step 2: remove bullets and make elements inline.
 * Also: bump up the line-height and margins to increase space
 * between tap-targets (SC 2.5.5). Google a11y guidelines require 8 CSS
 * pixels between tap targets. */
nav ul li {
	display: inline-block;
	margin-right: .5em;
}
/* narrow screens: we reduce margin for blockquotes a lot, using
 * a border instead. */
blockquote {
	border-left: 3px solid;
}

/* Narrow screens: allow hyphenating titles
 * I can't add soft hyphens to these. */
h1 {
	-webkit-hyphens: auto;
	hyphens: auto;
}

/* Very narrow screens: full hyphenation.
 * This is the typical width of a smart feature phone. */
@media (max-width: 15em) {
	body {
		font-size: 100%;
		-webkit-hyphens: auto;
		hyphens: auto;
		padding: 0 8px;
	}
}

/* <kbd> should be distinguished from <code> and surrounding text
 * in a way beyond font-face; at least two visual distinctions needed
 * Also, Small text is easier to read when slightly bolder.
 * This is important in the dark theme where I set my own colors and
 * try to maintain good perceptual contrast even for small text, but
 * I don't want toggling the theme to impact anything besides color so
 * I set the weight here. */
dt,
kbd {
	font-weight: bold;
}

/* <ins> should not be mistaken for hyperlinks.
 * "note" roles should look distinct. */
ins,
[role="note"],
[role="doc-tip"] {
	font-style: italic;
	text-decoration: none;
}

/* narrow screens: remove unused figure margins
 * figure captions shouldn't look like regular paragraphs; there should
 * be some extra space.
 * This does not hold true for figures in somewhat distinct sections; the
 * section should instead get the spacing. A section that constitutes a
 * separate schema.org object would qualify. */
section[itemprop="mentions"],
figure {
	margin: 1.5em 0;
}

section[itemprop="mentions"] > figure {
	margin: 0;
}

/* browsers make monospace small and unreadable for some dumb legacy
 * reason and this somehow fixes that without overriding the user's
 * font size preferences. */
code,
kbd,
pre, /* Needed for ancient browsers */
samp {
	font-family: monospace, monospace;
}

/* Some browsers don't support the hidden attr.
 * I use hidden spans in backlinks to provide ARIA labels.
 * Some ancient browsers don't support input[type="hidden"] */
span[hidden],
input[type="hidden"] {
	display: none;
}

/* Remove list style from data feeds. */
main[itemtype="https://schema.org/DataFeed"] > ol {
	padding: 0;
	list-style-type: none;
}

/* Narrow screens: long words can cause content to flow out of the
 * viewport, triggering horizontal scrolling. Allow breaking words in
 * content I don't control (comments, names). For content I do control,
 * I just add soft hyphens to the HTML. */
div[itemprop="comment"],
:not(pre) > code,
:not(pre) > samp,
span[itemtype="https://schema.org/Person"] {
	overflow-wrap: break-word;
}

/* Narrow screens: allow horizontal scroll in a pre block. */
pre {
	overflow: auto;
	padding: .5em;
}

/* Distinguish images from the background in case their color is
 * too similar to the page background color. Also put a border around
 * <pre> and <code> to distinguish them in ways besides font-family.
 * The tappable region of a <summary> extends across the page: we
 * need to tell users that the full space is interactive.
 * This is Technique C25 of SC 1.4.8 */
input,
img,
mark, /* borders provide a distinguishing factor besides color */
pre,
summary {
	border: 1px solid;
}

/* A black border is too harsh; the extra visual noise is distracting
 * to users with eye-tracking or ADHD. Only special items like headings
 * should draw gaze. */
:not(pre) > code,
:not(pre) > samp {
	border: 1px solid #999;

	/* borders shouldn't touch text */
	padding: 0 .25em;
}

/* center standalone images; same justification as
 * for centering the body contents. Also makes images easier to see
 * for people holding a device with one hand. */
div[itemprop="articleBody"] img {
	display: block;
	height: auto;
	margin: auto;
	max-width: 100%;
}

audio {
	width: 100%;
}

/* Some images look blurry when scaled; this makes them easier to
 * read. */
.pix {
	image-rendering: pixelated;
}

/* Make search box and submit button as wide as possible while keeping
 * them next to each other. */

/* Use table-style layout (no, not actual tables. eww.). It's like a
 * single-row flexbox that supports more browsers. Kanged this CSS from
 * ww.gov.uk. Give the entire width of the row to the search box, but
 * allow the minimum width for the submit button. */
legend, /* Makes the <legend> wrap text in some browsers. */
form > div {
	display: table;
	width: 100%
}

input {
	/* Browsers like Safari make the submit button pill-shaped which
	 * clashes with the input box. The only purely-cosmetic change on this
	 * site. */
	appearance: none;

	/* Don't shrink the size of the text in forms or make it system-ui. */
	font-family: sans-serif;
	font-size: inherit;
}

/* A text box should take all available width */
input:not([type="submit"]) {
	display: table-cell;
	width: 98%;
}

/* Pseudo-table-cell containing the submit button */
form > div > div {
	display: table-cell;
	vertical-align: top; /* IE and some botique browsers need this */
	width: 1%;
}


/* Some browser focus indicators are inaccessible; override them with
 * something more visible. See WCAG 2.x SC 2.4.12. I also tried to
 * match browser behavior; mainstream browsers use :focus-visible
 * instead of focus but older/simpler browsers only support :focus.
 * I borrowed these directives from
 * https://www.tempertemper.net/blog/refining-focus-styles-with-focus-visible
 * To my knowledge: <a>, <summary>, and <pre tabindex=0> are the only
 * focusable elements.
 * */

a:focus,
summary:focus,
pre[tabindex]:focus,
form :focus {
	outline: 3px solid;
}

/* Remove :focus styling for browsers that do support :focus-visible.
 * Leave it on for form stuff. */
@supports selector(:focus-visible) {
	a:focus:not(:focus-visible),
	summary:focus:not(:focus-visible),
	pre[tabindex]:focus:not(:focus-visible) {
		outline: none;
	}
}

/* Todo:
 * - Some browsers don't scale SVGs properly; the img container
 *   dimensions crop the image rather than scale it. Investigate
 *   if this only applies to Internet Explorer or if it applies to
 *   other uncommon browsers too. If any non-IE browsers do this and/or
 *   if the spec allows this behavior, try to correct it here.
 * - Wait till Webkit fixes its broken-ass default dark stylesheet
 *   then consider trimming the dark stylesheet I provide.
 * */