theme/reference.css - rust-lang/reference - Git at Google

 /* Custom CSS for the Rust Specification. */

 /*
 .parenthetical class used to keep e.g. "less-than symbol (<)" from wrapping
 the end parenthesis onto its own line. Use in a span between the last word and
 the parenthetical. So for this example, you'd use
 ```less-than <span class="parenthetical">symbol (`<`)</span>```
 */
 .parenthetical {
     white-space: nowrap;
 }

 /*
 Warnings are defined using admonitions in blockquotes:

 > [!WARNING]
 > This is bad!

 */
 main .warning blockquote {
     padding: 0px;
 }

 main .warning blockquote p {
     padding: 0px 20px;
     margin: 10px 0;
 }

 main .warning blockquote p:first-child::before {
     content: "⚠️ ";
 }

 .light main .warning blockquote,
 .rust main .warning blockquote {
     border: 2px solid red;
     background: #ffcece;
 }

 .rust main .warning blockquote {
     /* overrides previous declaration */
     border-color: #961717;
 }

 .coal main .warning blockquote,
 .navy main .warning blockquote,
 .ayu main .warning blockquote {
     background: #542626;
 }

 /* Make the links higher contrast on dark themes */
 .coal main .warning blockquote p a,
 .navy main .warning blockquote p a,
 .ayu main .warning blockquote p a {
     color: #80d0d0;
 }

 /* <kbd> tags can be used to highlight specific character elements. */
 kbd {
     border: 1px solid #999;
     display: inline-block;
     border-radius: 3px;
     padding: 0 0.6ex;
     background: #eee;
     box-shadow: inset -1px -1px 0 #999;
     vertical-align: baseline;
     color: #000;
     height: 1.55em;
     font-style: normal;
     font-weight: bold;
     font-family: inherit;
     font-size: revert;
     line-height: revert;
 }
 kbd.optional {
     border-style: dashed;
     background: #fff;
 }
 var.optional {
     border-style: dashed;
 }

 /* <var> tags can be used for non-terminals. */
 var {
     border: 1px solid #9c9;
     box-shadow: inset -1px -1px 0 #9c9;
     font-style: normal;
     display: inline-block;
     vertical-align: baseline;
     border-radius: 7px;
     padding: 0 4px;
     background: #dfd;
     margin: 2px;
 }
 var.type {
     box-shadow: inset -1px -1px 0 #c99;
     border-color: #c99;
     background: #fdd;
 }

 /* <span class="repeat"> can be used for a grammar production that repeats zero or more times. */
 span.repeat {
     position: relative;
     border: 1px dashed #393;
     border-radius: 10px;
     display: inline-block;
     padding: 6px;
     margin-left: 0.5ex;
     margin-top: 1em;
     margin-bottom: 0.5ex;
     min-width: 3.8em;
     text-align: center;
 }
 span.repeat::before {
     content: "zero or more";
     white-space: nowrap;
     display: block;
     text-align: center;
     font-size: 0.75em;
     position: absolute;
     left: 0;
     right: 0;
     top: -1.4em;
     color: #393;
 }
 var > span {
     display: inline-block;
     border-right: 1px dotted green;
     padding-right: 0.5ex;
     margin-right: 0.5ex;
     font-style: italic;
 }

 /* <span class="version"> can be used to highlight a specific version of Rust. */
 span.version {
     float: right;
     margin-left: 1em;
     margin-bottom: 1em;
     background: #f7c0eb;
     padding: 0.2ex 0.5ex;
     border-radius: 5px;
     display: block;
     box-shadow: inset -1px -1px 0 #a06894;
     font-size: 0.9em;
 }

 /* <dfn> tags are used to indicate a specific word or phrase is being defined. */
 dfn {
     font-style: italic;
     text-decoration: underline;
 }

 .content main {
     /* Provides space on the left for the rule call-outs. */
     padding-left: 4em;
 }

 /* Rules are generated via r[foo.bar] syntax, processed by mdbook-spec. */
 .rule {
     --font-size-mult: 0.8;
     --font-size: calc(1em * var(--font-size-mult));

     font-size: var(--font-size);
 }

 /* included in the grid below as 20px */
 .page, .content {
     padding-left: 0;
     padding-right: 0;
 }
 /* required to accomodate above, somehow... */
 #menu-bar {
     margin-left: 0;
 }

 main {
     /* To nicely display rules (`[a.b.c]`) on a side of the main text body we
        use grid layout. */
     display: grid;
     grid-template-columns:
         /* Left margin / place for rules */
         [rules] minmax(20px, 1fr)
         /* The main text body */
         [text] auto
         /* Right margin */
         [margin] minmax(20px, 1fr);

     /* We do these by hand via the grid */
     margin: 0;
     padding: 0 !important;
     max-width: none !important;
 }

 main > * {
     /* By default grid items can't be smaller than their content.
        That is, by default `min-width: auto`.
        We want to be able to force code blocks to be scrollable,
        so we need to overwrite `min-width`. */
     min-width: 0;
     max-width: var(--content-max-width);

     /* All elements should be in the main text body... */
     grid-column: text;
 }

 main > .rule {
     /* ... except the rules, which must be in the left margin */
     grid-column: rules;
 }

 /* Unset footnote margin,
    see below for more information about margins */
 /* FIXME: this doesn't work. `unset` can still break the margin of the next element,
           and since mdbook applies the margin to `:not(.footnore-definition)`,
           it can literally be anything, so there is no way to properly fix it,
           without changing mdbook... */
 :not(.footnote-definition) + .footnote-definition,
 .footnote-definition + :not(.footnote-definition) {
     margin-block-start: unset;
 }

 :not(.footnote-definition) + .footnote-definition {
      margin-top: calc(2em - 16px);
 }

 .footnote-definition:has(+ :not(.footnote-definition)) {
     margin-bottom: calc(2em - 16px);
 }

 /* This is quite dumb, ugh.
    CSS doesn't allow margin colapsing between grid items and anything else
    (src: <https://stackoverflow.com/a/37837971>), which means that the margins
    of li's children are not collapsed with ul's margins, adding too much margins.

    Ideally we'd add `<div>`s for each grid cell, so that margin collapsing happens
    as-usual inside of them. But, we don't have that kind of control over mdbook. */
 main > ul > li > *:first-child,
 main > ul > li > pre:first-child > pre.playground {
     margin-top: 0;
 }
 main > ul > li > *:last-child,
 main > ul > li > pre:last-child > pre.playground {
     margin-bottom: 0;
 }

 /* Similarly to the above, margin collapse doesn't happen between grid items,
    so we have to replace it with grid gap. (p, pre, and ul had 16px vertical margins) */
 main {
     row-gap: 16px;
 }
 main > p,
 main > pre,
 main > pre > pre.playground,
 main > ul {
     margin-top: 0;
     margin-bottom: 0;
 }

 /* Values for header margin-top and blockquote margin are taken from mdbook's general.css,
    values for header margin-bottom are taken from <https://www.w3schools.com/cssref/css_default_values.php> */
 main > h2 {
     margin-top: calc(2.5em - 16px);
     margin-bottom: calc(0.83em - 16px);
 }
 main > h3 {
     margin-top: calc(2.5em - 16px);
     margin-bottom: calc(1em - 16px);
 }
 main > h4 {
     margin-top: calc(2em - 16px);
     margin-bottom: calc(1.33em - 16px);
 }
 main > h5 {
     margin-top: calc(2em - 16px);
     margin-bottom: calc(1.67em - 16px);
 }
 main > h6 {
     margin-top: calc(2em - 16px);
     margin-bottom: calc(2.33em - 16px);
 }
 main > blockquote {
     margin-top: calc(20px - 16px);
     margin-bottom: calc(20px - 16px);
 }

 main > .rule {
     max-width: unset;
     justify-self: right;
     width: 100%;
     /* We use a container query to know the size of the "left margin",
        so that we can hide rules is there is not enough space. */
     container-type: inline-size;
     container-name: rule;
 }

 .rule-link {
     float: right;
     text-align: right;
     padding-right: 10px;
     /* We add `<wbr>` ourselves and only want breaks there */
     word-break: keep-all;
     /* Remove the blue coloring of links on rules that mdbook normally sets. */
     color: #999 !important;
 }

 /* When clicking a rule, it is added as a URL fragment and the browser will
    navigate to it. This adds an indicator that the linked rule is the one that
    is "current", just like normal headers are in mdbook.
 */
 .rule:target a::before {
     display: inline-block;
     content: "»";
     padding-right: 5px;
 }

 /* Dodge » from headings */
 .rule:has(+ h1:target),
 .rule:has(+ h2:target),
 .rule:has(+ h3:target),
 .rule:has(+ h4:target),
 .rule:has(+ h5:target),
 .rule:has(+ h6:target) {
     padding-right: 24px;
 }

 /* Hide the rules if the width of the container is too small.
    The cutoff point is chosen semi-arbitrary, it felt that
    when `width < 14em`, there are too many breaks. */
 @container rule (width < 14em) {
     main > .rule a span {
         display: none;
     }

     main > .rule a::before {
         content: "[*]";
     }
 }

 /* Align rules to various siblings */
 .rule:has(+ p),
 .rule:has(+ ul) {
     margin-top: calc((1em - var(--font-size)) / var(--font-size-mult) / 2);
 }

 .rule:has(+ h1) {
     align-self: center;
 }

 .rule:has(+ h2) {
     /* multiplying by this turns h2's em into .rule's em*/
     --h2-em-mult: calc(
         (1 / var(--font-size-mult)) /* to main font size */
           * 1.5 /* to h2 font size */
     );

     margin-top: calc(
         /* h2 margin top */
         2.5em * var(--h2-em-mult) - 16px
         /* half of the font size difference */
         + (1em * var(--h2-em-mult) - 1em) / 2
     )
 }
 .rule:has(+ h3) {
     /* multiplying by this turns h3's em into .rule's em*/
     --h3-em-mult: calc(
         (1 / var(--font-size-mult)) /* to main font size */
           * 1.17 /* to h3 font size */
     );

     margin-top: calc(
         /* h3 margin top */
         2.5em * var(--h3-em-mult) - 16px
         /* half of the font size difference */
         + (1em * var(--h3-em-mult) - 1em) / 2
     )
 }

 .rule:has(+ h4) {
     /* multiplying by this turns h4's em into .rule's em*/
     --h4-em-mult: calc(
         (1 / var(--font-size-mult)) /* to main font size */
           * 1 /* to h4 font size */
     );

     margin-top: calc(
         /* h4 margin top */
         2em * var(--h4-em-mult) - 16px
         /* half of the font size difference */
         + (1em * var(--h4-em-mult) - 1em) / 2
     )
 }

 .rule:has(+ h5) {
     /* multiplying by this turns h5's em into .rule's em*/
     --h5-em-mult: calc(
         (1 / var(--font-size-mult)) /* to main font size */
           * 0.83 /* to h5 font size */
     );

     margin-top: calc(
         /* h5 margin top */
         2em * var(--h5-em-mult) - 16px
         /* half of the font size difference */
         + (1em * var(--h5-em-mult) - 1em) / 2
     )
 }

 .rule:has(+ h6) {
     /* multiplying by this turns h6's em into .rule's em*/
     --h6-em-mult: calc(
         (1 / var(--font-size-mult)) /* to main font size */
           * 0.67 /* to h6 font size */
     );

     margin-top: calc(
         /* h6 margin top */
         2em * var(--h6-em-mult) - 16px
         /* half of the font size difference */
         + (1em * var(--h6-em-mult) - 1em) / 2
     )
 }

 /* Sets the color for [!HISTORY] blockquote admonitions. */
 .history > blockquote {
     background: #f7c0eb;
 }

 /* Provides a anchor container for positioning popups. */
 .popup-container {
     position: relative;
 }
 /* In the test summary page, a convenience class for toggling visibility. */
 .popup-hidden {
     display: none;
 }
 /* In the test summary page, the styling for the uncovered rule popup. */
 .uncovered-rules-popup {
     position: absolute;
     left: -250px;
     width: 400px;
     background: var(--bg);
     border-radius: 4px;
     border: 1px solid;
     z-index: 1000;
     padding: 1rem;
 }

 /* The popup that shows when viewing tests for a specific rule. */
 .tests-popup {
     color: var(--fg);
     background: var(--bg);
     border-radius: 4px;
     border: 1px solid;
     z-index: 1000;
     padding: 1rem;
 }
	/* Custom CSS for the Rust Specification. */

	/*
	.parenthetical class used to keep e.g. "less-than symbol (<)" from wrapping
	the end parenthesis onto its own line. Use in a span between the last word and
	the parenthetical. So for this example, you'd use
	```less-than <span class="parenthetical">symbol (`<`)</span>```
	*/
	.parenthetical {
	white-space: nowrap;
	}

	/*
	Warnings are defined using admonitions in blockquotes:

	> [!WARNING]
	> This is bad!

	*/
	main .warning blockquote {
	padding: 0px;
	}

	main .warning blockquote p {
	padding: 0px 20px;
	margin: 10px 0;
	}

	main .warning blockquote p:first-child::before {
	content: "⚠️ ";
	}

	.light main .warning blockquote,
	.rust main .warning blockquote {
	border: 2px solid red;
	background: #ffcece;
	}

	.rust main .warning blockquote {
	/* overrides previous declaration */
	border-color: #961717;
	}

	.coal main .warning blockquote,
	.navy main .warning blockquote,
	.ayu main .warning blockquote {
	background: #542626;
	}

	/* Make the links higher contrast on dark themes */
	.coal main .warning blockquote p a,
	.navy main .warning blockquote p a,
	.ayu main .warning blockquote p a {
	color: #80d0d0;
	}

	/* <kbd> tags can be used to highlight specific character elements. */
	kbd {
	border: 1px solid #999;
	display: inline-block;
	border-radius: 3px;
	padding: 0 0.6ex;
	background: #eee;
	box-shadow: inset -1px -1px 0 #999;
	vertical-align: baseline;
	color: #000;
	height: 1.55em;
	font-style: normal;
	font-weight: bold;
	font-family: inherit;
	font-size: revert;
	line-height: revert;
	}
	kbd.optional {
	border-style: dashed;
	background: #fff;
	}
	var.optional {
	border-style: dashed;
	}

	/* <var> tags can be used for non-terminals. */
	var {
	border: 1px solid #9c9;
	box-shadow: inset -1px -1px 0 #9c9;
	font-style: normal;
	display: inline-block;
	vertical-align: baseline;
	border-radius: 7px;
	padding: 0 4px;
	background: #dfd;
	margin: 2px;
	}
	var.type {
	box-shadow: inset -1px -1px 0 #c99;
	border-color: #c99;
	background: #fdd;
	}

	/* <span class="repeat"> can be used for a grammar production that repeats zero or more times. */
	span.repeat {
	position: relative;
	border: 1px dashed #393;
	border-radius: 10px;
	display: inline-block;
	padding: 6px;
	margin-left: 0.5ex;
	margin-top: 1em;
	margin-bottom: 0.5ex;
	min-width: 3.8em;
	text-align: center;
	}
	span.repeat::before {
	content: "zero or more";
	white-space: nowrap;
	display: block;
	text-align: center;
	font-size: 0.75em;
	position: absolute;
	left: 0;
	right: 0;
	top: -1.4em;
	color: #393;
	}
	var > span {
	display: inline-block;
	border-right: 1px dotted green;
	padding-right: 0.5ex;
	margin-right: 0.5ex;
	font-style: italic;
	}

	/* <span class="version"> can be used to highlight a specific version of Rust. */
	span.version {
	float: right;
	margin-left: 1em;
	margin-bottom: 1em;
	background: #f7c0eb;
	padding: 0.2ex 0.5ex;
	border-radius: 5px;
	display: block;
	box-shadow: inset -1px -1px 0 #a06894;
	font-size: 0.9em;
	}

	/* <dfn> tags are used to indicate a specific word or phrase is being defined. */
	dfn {
	font-style: italic;
	text-decoration: underline;
	}

	.content main {
	/* Provides space on the left for the rule call-outs. */
	padding-left: 4em;
	}

	/* Rules are generated via r[foo.bar] syntax, processed by mdbook-spec. */
	.rule {
	--font-size-mult: 0.8;
	--font-size: calc(1em * var(--font-size-mult));

	font-size: var(--font-size);
	}

	/* included in the grid below as 20px */
	.page, .content {
	padding-left: 0;
	padding-right: 0;
	}
	/* required to accomodate above, somehow... */
	#menu-bar {
	margin-left: 0;
	}

	main {
	/* To nicely display rules (`[a.b.c]`) on a side of the main text body we
	use grid layout. */
	display: grid;
	grid-template-columns:
	/* Left margin / place for rules */
	[rules] minmax(20px, 1fr)
	/* The main text body */
	[text] auto
	/* Right margin */
	[margin] minmax(20px, 1fr);

	/* We do these by hand via the grid */
	margin: 0;
	padding: 0 !important;
	max-width: none !important;
	}

	main > * {
	/* By default grid items can't be smaller than their content.
	That is, by default `min-width: auto`.
	We want to be able to force code blocks to be scrollable,
	so we need to overwrite `min-width`. */
	min-width: 0;
	max-width: var(--content-max-width);

	/* All elements should be in the main text body... */
	grid-column: text;
	}

	main > .rule {
	/* ... except the rules, which must be in the left margin */
	grid-column: rules;
	}

	/* Unset footnote margin,
	see below for more information about margins */
	/* FIXME: this doesn't work. `unset` can still break the margin of the next element,
	and since mdbook applies the margin to `:not(.footnore-definition)`,
	it can literally be anything, so there is no way to properly fix it,
	without changing mdbook... */
	:not(.footnote-definition) + .footnote-definition,
	.footnote-definition + :not(.footnote-definition) {
	margin-block-start: unset;
	}

	:not(.footnote-definition) + .footnote-definition {
	margin-top: calc(2em - 16px);
	}

	.footnote-definition:has(+ :not(.footnote-definition)) {
	margin-bottom: calc(2em - 16px);
	}

	/* This is quite dumb, ugh.
	CSS doesn't allow margin colapsing between grid items and anything else
	(src: <https://stackoverflow.com/a/37837971>), which means that the margins
	of li's children are not collapsed with ul's margins, adding too much margins.

	Ideally we'd add `<div>`s for each grid cell, so that margin collapsing happens
	as-usual inside of them. But, we don't have that kind of control over mdbook. */
	main > ul > li > *:first-child,
	main > ul > li > pre:first-child > pre.playground {
	margin-top: 0;
	}
	main > ul > li > *:last-child,
	main > ul > li > pre:last-child > pre.playground {
	margin-bottom: 0;
	}

	/* Similarly to the above, margin collapse doesn't happen between grid items,
	so we have to replace it with grid gap. (p, pre, and ul had 16px vertical margins) */
	main {
	row-gap: 16px;
	}
	main > p,
	main > pre,
	main > pre > pre.playground,
	main > ul {
	margin-top: 0;
	margin-bottom: 0;
	}

	/* Values for header margin-top and blockquote margin are taken from mdbook's general.css,
	values for header margin-bottom are taken from <https://www.w3schools.com/cssref/css_default_values.php> */
	main > h2 {
	margin-top: calc(2.5em - 16px);
	margin-bottom: calc(0.83em - 16px);
	}
	main > h3 {
	margin-top: calc(2.5em - 16px);
	margin-bottom: calc(1em - 16px);
	}
	main > h4 {
	margin-top: calc(2em - 16px);
	margin-bottom: calc(1.33em - 16px);
	}
	main > h5 {
	margin-top: calc(2em - 16px);
	margin-bottom: calc(1.67em - 16px);
	}
	main > h6 {
	margin-top: calc(2em - 16px);
	margin-bottom: calc(2.33em - 16px);
	}
	main > blockquote {
	margin-top: calc(20px - 16px);
	margin-bottom: calc(20px - 16px);
	}

	main > .rule {
	max-width: unset;
	justify-self: right;
	width: 100%;
	/* We use a container query to know the size of the "left margin",
	so that we can hide rules is there is not enough space. */
	container-type: inline-size;
	container-name: rule;
	}

	.rule-link {
	float: right;
	text-align: right;
	padding-right: 10px;
	/* We add `<wbr>` ourselves and only want breaks there */
	word-break: keep-all;
	/* Remove the blue coloring of links on rules that mdbook normally sets. */
	color: #999 !important;
	}

	/* When clicking a rule, it is added as a URL fragment and the browser will
	navigate to it. This adds an indicator that the linked rule is the one that
	is "current", just like normal headers are in mdbook.
	*/
	.rule:target a::before {
	display: inline-block;
	content: "»";
	padding-right: 5px;
	}

	/* Dodge » from headings */
	.rule:has(+ h1:target),
	.rule:has(+ h2:target),
	.rule:has(+ h3:target),
	.rule:has(+ h4:target),
	.rule:has(+ h5:target),
	.rule:has(+ h6:target) {
	padding-right: 24px;
	}

	/* Hide the rules if the width of the container is too small.
	The cutoff point is chosen semi-arbitrary, it felt that
	when `width < 14em`, there are too many breaks. */
	@container rule (width < 14em) {
	main > .rule a span {
	display: none;
	}

	main > .rule a::before {
	content: "[*]";
	}
	}

	/* Align rules to various siblings */
	.rule:has(+ p),
	.rule:has(+ ul) {
	margin-top: calc((1em - var(--font-size)) / var(--font-size-mult) / 2);
	}

	.rule:has(+ h1) {
	align-self: center;
	}

	.rule:has(+ h2) {
	/* multiplying by this turns h2's em into .rule's em*/
	--h2-em-mult: calc(
	(1 / var(--font-size-mult)) /* to main font size */
	* 1.5 /* to h2 font size */
	);

	margin-top: calc(
	/* h2 margin top */
	2.5em * var(--h2-em-mult) - 16px
	/* half of the font size difference */
	+ (1em * var(--h2-em-mult) - 1em) / 2
	)
	}
	.rule:has(+ h3) {
	/* multiplying by this turns h3's em into .rule's em*/
	--h3-em-mult: calc(
	(1 / var(--font-size-mult)) /* to main font size */
	* 1.17 /* to h3 font size */
	);

	margin-top: calc(
	/* h3 margin top */
	2.5em * var(--h3-em-mult) - 16px
	/* half of the font size difference */
	+ (1em * var(--h3-em-mult) - 1em) / 2
	)
	}

	.rule:has(+ h4) {
	/* multiplying by this turns h4's em into .rule's em*/
	--h4-em-mult: calc(
	(1 / var(--font-size-mult)) /* to main font size */
	* 1 /* to h4 font size */
	);

	margin-top: calc(
	/* h4 margin top */
	2em * var(--h4-em-mult) - 16px
	/* half of the font size difference */
	+ (1em * var(--h4-em-mult) - 1em) / 2
	)
	}

	.rule:has(+ h5) {
	/* multiplying by this turns h5's em into .rule's em*/
	--h5-em-mult: calc(
	(1 / var(--font-size-mult)) /* to main font size */
	* 0.83 /* to h5 font size */
	);

	margin-top: calc(
	/* h5 margin top */
	2em * var(--h5-em-mult) - 16px
	/* half of the font size difference */
	+ (1em * var(--h5-em-mult) - 1em) / 2
	)
	}

	.rule:has(+ h6) {
	/* multiplying by this turns h6's em into .rule's em*/
	--h6-em-mult: calc(
	(1 / var(--font-size-mult)) /* to main font size */
	* 0.67 /* to h6 font size */
	);

	margin-top: calc(
	/* h6 margin top */
	2em * var(--h6-em-mult) - 16px
	/* half of the font size difference */
	+ (1em * var(--h6-em-mult) - 1em) / 2
	)
	}

	/* Sets the color for [!HISTORY] blockquote admonitions. */
	.history > blockquote {
	background: #f7c0eb;
	}

	/* Provides a anchor container for positioning popups. */
	.popup-container {
	position: relative;
	}
	/* In the test summary page, a convenience class for toggling visibility. */
	.popup-hidden {
	display: none;
	}
	/* In the test summary page, the styling for the uncovered rule popup. */
	.uncovered-rules-popup {
	position: absolute;
	left: -250px;
	width: 400px;
	background: var(--bg);
	border-radius: 4px;
	border: 1px solid;
	z-index: 1000;
	padding: 1rem;
	}

	/* The popup that shows when viewing tests for a specific rule. */
	.tests-popup {
	color: var(--fg);
	background: var(--bg);
	border-radius: 4px;
	border: 1px solid;
	z-index: 1000;
	padding: 1rem;
	}