/* =========================================================================
   C++23 Course theme
   Paper and ink of a standards document; blue from the C++ logo;
   green only for passed checks.
   ========================================================================= */

:root {
	--paper: #f6f8fa;
	--paper-raised: #ffffff;
	--ink: #16243a;
	--ink-soft: #4b5b71;
	--rule: #d6dde6;
	--rule-strong: #b9c4d2;
	--blue: #00599c;
	--blue-deep: #004482;
	--blue-wash: #e6eff7;
	--ok: #2c7a3f;
	--ok-wash: #e8f3eb;
	--warn: #a8620a;
	--code-bg: #13213a;
	--code-ink: #d9e2ee;
	--code-dim: #7f93ad;
	--focus: #0a84ff;

	--serif: "Source Serif 4", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
	--mono: "JetBrains Mono", ui-monospace, "Cascadia Code", Consolas, monospace;

	--step--1: 0.889rem;  /* 16px */
	--step-0: 1.125rem;   /* 18px body */
	--step-1: 1.3125rem;  /* 21px */
	--step-2: 1.5rem;     /* 24px */
	--step-3: 2.25rem;    /* 36px */
	--step-4: 3rem;       /* 48px */

	--measure: 40rem;
	--gutter: 1rem;
	--radius: 4px;

	color-scheme: light;
}

@media (prefers-color-scheme: dark) {
	:root:not([data-theme="light"]) {
		--paper: #0f1a2b;
		--paper-raised: #142236;
		--ink: #dde5ef;
		--ink-soft: #9aabc0;
		--rule: #24344b;
		--rule-strong: #34486a;
		--blue: #6cb2ea;
		--blue-deep: #93c6f0;
		--blue-wash: #16304c;
		--ok: #63c07c;
		--ok-wash: #15301f;
		--warn: #e0a24a;
		--code-bg: #0a1322;
		color-scheme: dark;
	}
}
:root[data-theme="dark"] {
	--paper: #0f1a2b;
	--paper-raised: #142236;
	--ink: #dde5ef;
	--ink-soft: #9aabc0;
	--rule: #24344b;
	--rule-strong: #34486a;
	--blue: #6cb2ea;
	--blue-deep: #93c6f0;
	--blue-wash: #16304c;
	--ok: #63c07c;
	--ok-wash: #15301f;
	--warn: #e0a24a;
	--code-bg: #0a1322;
	color-scheme: dark;
}

/* The plugin's components take the theme's colors. html:root outranks the plugin's :root. */
html:root {
	--cpp23-accent: var(--blue);
	--cpp23-accent-soft: var(--blue-wash);
	--cpp23-ok: var(--ok);
	--cpp23-ok-soft: var(--ok-wash);
	--cpp23-border: var(--rule);
	--cpp23-muted: var(--ink-soft);
	--cpp23-radius: var(--radius);
}

/* ---------- Base ---------- */

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

html { -webkit-text-size-adjust: 100%; }

body {
	margin: 0;
	background: var(--paper);
	color: var(--ink);
	font-family: var(--serif);
	font-size: var(--step-0);
	line-height: 1.65;
	font-optical-sizing: auto;
	text-rendering: optimizeLegibility;
	-webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
	margin: 2em 0 0.5em;
	font-weight: 640;
	line-height: 1.2;
	letter-spacing: -0.01em;
	text-wrap: balance;
}
h1 { font-size: var(--step-3); line-height: 1.12; }
h2 { font-size: var(--step-2); }
h3 { font-size: var(--step-1); }
h4 { font-size: var(--step-0); }

p, ul, ol, pre, figure, table, blockquote { margin: 0 0 1.1em; }

a { color: var(--blue); text-decoration-thickness: 1px; text-underline-offset: 0.18em; }
a:hover { color: var(--blue-deep); text-decoration-thickness: 2px; }

:focus-visible {
	outline: 2px solid var(--focus);
	outline-offset: 2px;
	border-radius: 2px;
}

img { max-width: 100%; height: auto; }
hr { border: 0; border-top: 1px solid var(--rule); margin: 2.5em 0; }

code, kbd, samp {
	font-family: var(--mono);
	font-size: 0.86em;
}
:not(pre) > code {
	padding: 0.08em 0.32em;
	border-radius: 3px;
	background: var(--blue-wash);
	color: var(--ink);
	overflow-wrap: break-word;
}
@media (min-width: 720px) {
	:not(pre) > code { white-space: nowrap; }
}

pre,
pre.cpp23-code,
.cpp23-lesson pre.cpp23-code,
.cpp23-forum-body pre.cpp23-code,
.comment-content pre.cpp23-code {
	background: var(--code-bg);
	color: var(--code-ink);
	border-radius: var(--radius);
	padding: 1em 1.15em;
	overflow-x: auto;
	font-family: var(--mono);
	font-size: 0.88rem;
	line-height: 1.6;
	tab-size: 4;
}
pre code,
pre.cpp23-code code {
	padding: 0;
	background: none;
	color: inherit;
	font-size: inherit;
}
/* Prism tokens tuned to the navy panel. */
pre .token.comment { color: var(--code-dim); font-style: italic; }
pre .token.keyword, pre .token.directive-hash, pre .token.directive { color: #8fc1f2; }
pre .token.string, pre .token.char { color: #a8d8a0; }
pre .token.number, pre .token.boolean { color: #f0c37a; }
pre .token.function { color: #e8e1b3; }
pre .token.class-name { color: #9ad8e6; }
pre .token.operator, pre .token.punctuation { color: #b5c3d6; }
pre .token.macro, pre .token.property { color: #c9a8ef; }

blockquote {
	margin-left: 0;
	padding-left: 1.1em;
	border-left: 3px solid var(--rule-strong);
	color: var(--ink-soft);
}

table { width: 100%; border-collapse: collapse; font-size: var(--step--1); }
th, td { text-align: left; padding: 0.5em 0.75em; border-bottom: 1px solid var(--rule); vertical-align: top; }
th { font-weight: 640; border-bottom-color: var(--rule-strong); }

.muted { color: var(--ink-soft); }
.screen-reader-text {
	position: absolute !important;
	width: 1px; height: 1px;
	overflow: hidden;
	clip: rect(1px, 1px, 1px, 1px);
	white-space: nowrap;
}
.skip-link {
	position: absolute;
	left: 1rem; top: -3rem;
	z-index: 100;
	padding: 0.5em 0.9em;
	background: var(--ink);
	color: var(--paper);
	border-radius: var(--radius);
}
.skip-link:focus { top: 1rem; }

.wrap {
	width: 100%;
	max-width: 74rem;
	margin: 0 auto;
	padding: 0 var(--gutter);
}
.wrap.narrow { max-width: calc(var(--measure) + 2 * var(--gutter)); }

@media (min-width: 720px) { :root { --gutter: 2rem; } }

/* ---------- Buttons ---------- */

.button,
button[type="submit"],
input[type="submit"],
.cpp23-button {
	display: inline-flex;
	align-items: center;
	gap: 0.4em;
	padding: 0.55em 1.05em;
	border: 1px solid var(--rule-strong);
	border-radius: var(--radius);
	background: var(--paper-raised);
	color: var(--ink) !important;
	font: 600 var(--step--1)/1.3 var(--serif);
	text-decoration: none;
	cursor: pointer;
}
.button:hover { border-color: var(--ink-soft); }
.button-primary,
button[type="submit"],
input[type="submit"],
.cpp23-button,
.cpp23-forum-form button[type="submit"] {
	background: var(--blue);
	border-color: var(--blue);
	color: #fff !important;
}
.button-primary:hover,
button[type="submit"]:hover,
input[type="submit"]:hover,
.cpp23-button:hover { background: var(--blue-deep); border-color: var(--blue-deep); }
:root[data-theme="dark"] .button-primary,
:root[data-theme="dark"] button[type="submit"],
:root[data-theme="dark"] input[type="submit"],
:root[data-theme="dark"] .cpp23-button { color: #0f1a2b !important; }
@media (prefers-color-scheme: dark) {
	:root:not([data-theme="light"]) .button-primary,
	:root:not([data-theme="light"]) button[type="submit"],
	:root:not([data-theme="light"]) input[type="submit"],
	:root:not([data-theme="light"]) .cpp23-button { color: #0f1a2b !important; }
}

input[type="text"], input[type="email"], input[type="url"], input[type="search"], input[type="password"], textarea, select {
	width: 100%;
	padding: 0.55em 0.7em;
	border: 1px solid var(--rule-strong);
	border-radius: var(--radius);
	background: var(--paper-raised);
	color: var(--ink);
	font: inherit;
	font-size: var(--step--1);
}
textarea { font-family: var(--mono); font-size: 0.84rem; line-height: 1.55; }

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

.site-header {
	border-bottom: 1px solid var(--rule);
	background: var(--paper);
}
.header-inner {
	display: flex;
	align-items: center;
	gap: 1.5rem;
	min-height: 4rem;
}
.brand {
	display: inline-flex;
	align-items: center;
	gap: 0.6rem;
	color: var(--ink);
	text-decoration: none;
	font-weight: 700;
	font-size: var(--step-1);
	letter-spacing: -0.015em;
	margin-right: auto;
}
.brand:hover { color: var(--ink); }
.brand-logo { width: auto; height: 2rem; }

.site-nav { display: flex; align-items: center; gap: 1.5rem; }
.nav-list {
	display: flex;
	gap: 1.4rem;
	list-style: none;
	margin: 0;
	padding: 0;
}
.nav-list a {
	color: var(--ink);
	text-decoration: none;
	font-size: var(--step--1);
	padding: 0.35em 0;
	border-bottom: 2px solid transparent;
}
.nav-list a:hover,
.nav-list .current-menu-item > a,
.nav-list a[aria-current="page"] { border-bottom-color: var(--blue); }

.account { display: flex; align-items: center; gap: 1rem; font-size: var(--step--1); }
.account a { color: var(--ink-soft); text-decoration: none; }
.account a:hover { color: var(--ink); }
.account-name { color: var(--ink-soft); }
.account .account-join {
	color: var(--blue);
	border: 1px solid var(--blue);
	border-radius: var(--radius);
	padding: 0.25em 0.7em;
}

.mode-toggle,
.nav-toggle {
	display: inline-grid;
	place-items: center;
	width: 2.25rem;
	height: 2.25rem;
	border: 1px solid var(--rule);
	border-radius: var(--radius);
	background: transparent;
	color: var(--ink-soft);
	cursor: pointer;
	padding: 0;
}
.mode-toggle .icon-sun { display: none; }
:root[data-theme="dark"] .mode-toggle .icon-moon { display: none; }
:root[data-theme="dark"] .mode-toggle .icon-sun { display: block; }
@media (prefers-color-scheme: dark) {
	:root:not([data-theme="light"]) .mode-toggle .icon-moon { display: none; }
	:root:not([data-theme="light"]) .mode-toggle .icon-sun { display: block; }
}
.mode-toggle:hover { color: var(--ink); border-color: var(--rule-strong); }
.nav-toggle { display: none; }
.nav-toggle-bars,
.nav-toggle-bars::before,
.nav-toggle-bars::after {
	display: block;
	width: 1rem;
	height: 2px;
	background: currentColor;
	position: relative;
	transition: transform 0.2s ease;
}
.nav-toggle-bars::before, .nav-toggle-bars::after { content: ""; position: absolute; left: 0; }
.nav-toggle-bars::before { top: -5px; }
.nav-toggle-bars::after { top: 5px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { transform: translateY(5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { transform: translateY(-5px) rotate(-45deg); }

@media (max-width: 760px) {
	.nav-toggle { display: inline-grid; }
	.site-nav {
		display: none;
		position: absolute;
		left: 0; right: 0; top: 4rem;
		z-index: 50;
		flex-direction: column;
		align-items: stretch;
		gap: 0;
		padding: 0.5rem var(--gutter) 1rem;
		background: var(--paper);
		border-bottom: 1px solid var(--rule);
	}
	.site-header { position: relative; }
	.site-nav.is-open { display: flex; }
	.nav-list { flex-direction: column; gap: 0; }
	.nav-list a { display: block; padding: 0.7em 0; border-bottom: 1px solid var(--rule); font-size: var(--step-0); }
	.account { padding: 0.9rem 0; justify-content: space-between; }
	.mode-toggle { align-self: flex-start; }
}

/* ---------- Footer ---------- */

.site-footer {
	margin-top: 5rem;
	border-top: 1px solid var(--rule);
	padding: 2rem 0 3rem;
	color: var(--ink-soft);
	font-size: var(--step--1);
}
.footer-inner { display: grid; gap: 0.75rem; }
.footer-note { max-width: var(--measure); margin: 0; }
.footer-list { display: flex; flex-wrap: wrap; gap: 1.2rem; list-style: none; margin: 0; padding: 0; }
.footer-list a { color: var(--ink-soft); }
.footer-copy { margin: 0; }

/* ---------- Page scaffolding ---------- */

.page-body { padding-top: 3rem; }
.page-header { margin-bottom: 1.75rem; }
.page-title { margin: 0; }
.entry > :first-child { margin-top: 0; }
.entry h2 { margin-top: 2.2em; }
.entry li { margin-bottom: 0.35em; }

/* ---------- Home: hero ---------- */

.hero {
	border-bottom: 1px solid var(--rule);
	padding: 4rem 0 4.5rem;
}
.hero-inner {
	display: grid;
	grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
	gap: 3.5rem;
	align-items: center;
}
.hero-title {
	margin: 0 0 0.45em;
	font-size: clamp(2.4rem, 1.6rem + 3vw, 3.75rem);
	font-weight: 700;
	line-height: 1.04;
	letter-spacing: -0.028em;
	font-variation-settings: "opsz" 60;
}
.hero-intro {
	max-width: 32rem;
	color: var(--ink-soft);
	font-size: var(--step-1);
	line-height: 1.55;
}
.hero-actions { display: flex; flex-wrap: wrap; gap: 0.75rem; margin: 1.75rem 0 0; }

.hero-program {
	margin: 0;
	outline: 1px solid var(--rule);
	outline-offset: -1px;
	background: var(--code-bg);
	border-radius: 6px;
	overflow: hidden;
	box-shadow: 0 1px 0 var(--rule), 0 18px 40px -24px rgba(19, 33, 58, 0.55);
}
.program-file {
	padding: 0.6rem 1.15rem;
	border-bottom: 1px solid rgba(255, 255, 255, 0.08);
	color: var(--code-dim);
	font: 0.78rem/1.4 var(--mono);
}
.hero-program pre.cpp23-code.program-source {
	margin: 0;
	border-radius: 0;
	padding: 1.1rem 1.15rem 1.2rem;
	font-size: 0.92rem;
	background: transparent;
}
.hero-program .cpp23-copy { display: none; }
.program-run {
	padding: 0.85rem 1.15rem 1rem;
	background: rgba(0, 0, 0, 0.22);
	border-top: 1px solid rgba(255, 255, 255, 0.06);
	font: 0.86rem/1.7 var(--mono);
}
.program-cmd { color: var(--code-dim); }
.program-cmd .prompt { color: #6f8db3; margin-right: 0.4em; }
.program-out { color: #e8f2ff; min-height: 1.7em; }
.program-out.is-typing::after {
	content: "";
	display: inline-block;
	width: 0.55em;
	height: 1.05em;
	margin-left: 1px;
	vertical-align: -0.15em;
	background: #8fc1f2;
	animation: cpp23t-caret 0.9s steps(1) infinite;
}
@keyframes cpp23t-caret { 50% { opacity: 0; } }

@media (max-width: 900px) {
	.hero { padding: 2.5rem 0 3rem; }
	.hero-inner { grid-template-columns: 1fr; gap: 2.25rem; }
}

/* ---------- Home: sections ---------- */

.home-section { padding: 3.5rem 0 0; }
/* Sections line up with the hero's left edge rather than centering. */
.home-section .wrap.narrow { max-width: 74rem; }
.home-section .wrap.narrow > * { max-width: var(--measure); }
.section-title { margin: 0 0 0.35em; }
.section-lede { color: var(--ink-soft); margin-bottom: 1.5rem; }

.method {
	counter-reset: step;
	list-style: none;
	margin: 1.25rem 0 0;
	padding: 0;
	display: grid;
	gap: 1.4rem;
}
.method li {
	counter-increment: step;
	display: grid;
	grid-template-columns: 2.75rem 1fr;
	column-gap: 1rem;
}
.method li::before {
	content: counter(step);
	grid-row: span 2;
	font-size: var(--step-3);
	font-weight: 300;
	line-height: 1;
	color: var(--blue);
	font-variation-settings: "opsz" 60;
}
.method h3 { margin: 0.1em 0 0.15em; }
.method p { margin: 0; color: var(--ink-soft); }

.recent-topics { list-style: none; margin: 0 0 1.25rem; padding: 0; border-top: 1px solid var(--rule); }
.recent-topics li {
	display: flex;
	flex-wrap: wrap;
	justify-content: space-between;
	gap: 0.25rem 1rem;
	padding: 0.75rem 0;
	border-bottom: 1px solid var(--rule);
}
.recent-topics a { font-weight: 600; text-decoration: none; }
.recent-topics .muted { font-size: var(--step--1); }

/* ---------- Lesson list (plugin tracker) ---------- */

.cpp23-tracker__summary {
	font-weight: 400;
	color: var(--ink-soft);
	font-size: var(--step--1);
	margin-bottom: 0.75rem;
}
.cpp23-tracker__list {
	border-top: 1px solid var(--rule);
	margin: 0 0 1.25rem;
}
.cpp23-tracker__list .cpp23-lesson-row {
	margin: 0;
	padding: 0.95rem 0;
	border: 0;
	border-bottom: 1px solid var(--rule);
	border-radius: 0;
	gap: 1rem;
}
.cpp23-lesson-row__status {
	flex: 0 0 1.25rem;
	height: 1.25rem;
	margin-top: 0.25em;
	border: 1.5px solid var(--rule-strong);
}
.cpp23-lesson-row.is-complete .cpp23-lesson-row__status::after { left: 0.36em; top: 0.12em; width: 0.32em; height: 0.6em; }
.cpp23-lesson-row__title { color: var(--ink); font-weight: 600; font-size: var(--step-1); }
.cpp23-lesson-row__title:hover { color: var(--blue); }
.cpp23-lesson-row__num {
	display: inline-block;
	min-width: 1.75rem;
	color: var(--ink-soft);
	font-weight: 400;
	font-variant-numeric: tabular-nums;
}
.cpp23-lesson-row__excerpt { font-size: var(--step--1); margin-top: 0.2em; padding-left: calc(1.75rem + 0.3em); }
.cpp23-lesson-row__count { font-variant-numeric: tabular-nums; margin-top: 0.35em; }

/* ---------- Lesson page ---------- */

.lesson-layout {
	display: grid;
	grid-template-columns: 17rem minmax(0, var(--measure));
	gap: 3.5rem;
	justify-content: center;
	padding-top: 2.5rem;
}
.lesson-aside { position: relative; }
.lesson-index {
	position: sticky;
	top: 1.5rem;
	max-height: calc(100vh - 3rem);
	overflow-y: auto;
	font-size: var(--step--1);
}
.lesson-index-summary {
	list-style: none;
	font-weight: 640;
	color: var(--ink);
	padding-bottom: 0.6rem;
	border-bottom: 1px solid var(--rule);
	cursor: default;
}
.lesson-index-summary::-webkit-details-marker { display: none; }
.lesson-index .cpp23-tracker__list { border-top: 0; margin: 0; }
.lesson-index .cpp23-lesson-row { padding: 0.55rem 0; gap: 0.6rem; border-bottom: 0; }
.lesson-index .cpp23-lesson-row__status { flex-basis: 0.95rem; height: 0.95rem; margin-top: 0.3em; }
.lesson-index .cpp23-lesson-row.is-complete .cpp23-lesson-row__status::after { left: 0.24em; top: 0.06em; width: 0.26em; height: 0.48em; border-width: 0 1.5px 1.5px 0; }
.lesson-index .cpp23-lesson-row__title { font-size: var(--step--1); font-weight: 500; line-height: 1.4; }
.lesson-index .cpp23-lesson-row__num { min-width: 1.3em; }
.lesson-index .cpp23-lesson-row.is-current .cpp23-lesson-row__title { font-weight: 700; color: var(--ink); }
.lesson-index .cpp23-lesson-row__count { font-size: 0.8rem; margin-top: 0.15em; }

.lesson-sections {
	list-style: none;
	margin: 0.45rem 0 0.2rem;
	padding: 0 0 0 1.3em;
	border-left: 1px solid var(--rule);
}
.lesson-sections li { margin: 0; }
.lesson-sections a {
	display: block;
	padding: 0.2rem 0 0.2rem 0.7rem;
	margin-left: -1px;
	border-left: 2px solid transparent;
	color: var(--ink-soft);
	text-decoration: none;
	line-height: 1.35;
}
.lesson-sections a:hover { color: var(--ink); }
.lesson-sections a.is-active { color: var(--blue); border-left-color: var(--blue); }

.lesson-header {
	display: flex;
	flex-wrap: wrap;
	align-items: baseline;
	justify-content: space-between;
	gap: 0.25rem 1.5rem;
	padding-bottom: 0.75rem;
	border-bottom: 2px solid var(--ink);
	margin-bottom: 1rem;
}
.lesson-title { margin: 0; flex: 1 1 20rem; }
.stable-name {
	font-family: var(--mono);
	font-size: 0.95rem;
	color: var(--ink-soft);
	white-space: nowrap;
}
.lesson-summary { color: var(--ink-soft); font-size: var(--step-1); line-height: 1.5; }

/* Plugin's progress strip under the title */
.cpp23-lesson-progress {
	border: 0;
	border-radius: 0;
	padding: 0;
	margin: 0 0 2.25rem;
	color: var(--ink-soft);
}
.cpp23-lesson-progress__row { font-size: var(--step--1); margin-bottom: 0.4rem; }
.cpp23-bar { height: 3px; border-radius: 0; background: var(--rule); }

.cpp23-lesson h2 { scroll-margin-top: 1.5rem; }
.cpp23-lesson pre.cpp23-code { margin: 1.25em 0 1.5em; }

/* Checks: a ruled block that turns green when passed */
.cpp23-check {
	margin: 2em 0;
	padding: 1rem 1.15rem 1.05rem;
	border: 1px solid var(--rule);
	border-left: 3px solid var(--blue);
	border-radius: 0 var(--radius) var(--radius) 0;
	background: var(--paper-raised);
}
.cpp23-check.is-done { border-left-color: var(--ok); background: var(--ok-wash); }
.cpp23-check__head { display: flex; align-items: baseline; gap: 0.6rem; margin-bottom: 0.45rem; }
.cpp23-check__badge {
	padding: 0;
	border-radius: 0;
	background: none;
	color: var(--blue);
	font: 600 0.82rem/1.4 var(--mono);
	letter-spacing: 0;
}
.cpp23-check.is-done .cpp23-check__badge { background: none; color: var(--ok); }
.cpp23-check__title { font-size: var(--step-0); }
.cpp23-check__toggle {
	margin-top: 0.4rem;
	font-weight: 600;
	font-size: var(--step--1);
}
.cpp23-check__box { accent-color: var(--ok); width: 1.1rem; height: 1.1rem; }

.cpp23-ask { font-size: var(--step--1); color: var(--ink-soft); margin-top: 3rem; }
.cpp23-lesson-nav a {
	border-radius: var(--radius);
	font-size: var(--step--1);
	color: var(--ink);
	background: var(--paper-raised);
}
.cpp23-lesson-nav a:hover { border-color: var(--blue); color: var(--blue); }

.cpp23-copy {
	font: 500 0.72rem/1.4 var(--mono);
	border-radius: 3px;
	color: var(--code-ink);
	border-color: rgba(255, 255, 255, 0.18);
	opacity: 0;
	transition: opacity 0.15s ease;
}
pre.cpp23-code:hover .cpp23-copy,
pre.cpp23-code:focus-within .cpp23-copy { opacity: 1; }
@media (hover: none) { .cpp23-copy { opacity: 1; } }

@media (max-width: 960px) {
	.lesson-layout { grid-template-columns: minmax(0, 1fr); gap: 1.5rem; padding-top: 1.25rem; }
	.lesson-index {
		position: static;
		max-height: none;
		border: 1px solid var(--rule);
		border-radius: var(--radius);
		padding: 0.6rem 0.9rem;
		background: var(--paper-raised);
	}
	.lesson-index-summary { border-bottom: 0; padding: 0.15rem 0; cursor: pointer; }
	.lesson-index-summary::after { content: " ▾"; color: var(--ink-soft); }
	.lesson-index[open] .lesson-index-summary { border-bottom: 1px solid var(--rule); padding-bottom: 0.5rem; margin-bottom: 0.2rem; }
}

/* ---------- Forum ---------- */

.cpp23-forum__bar { font-size: var(--step--1); color: var(--ink-soft); }
.cpp23-topics { border: 0; border-top: 1px solid var(--rule); border-radius: 0; }
.cpp23-topic { padding: 0.95rem 0; border-bottom: 1px solid var(--rule); }
.cpp23-topic:last-child { border-bottom: 1px solid var(--rule); }
.cpp23-topic__title { color: var(--ink); font-size: var(--step-0); }
.cpp23-topic__title:hover { color: var(--blue); }
.cpp23-topic__stats { font-variant-numeric: tabular-nums; }
.cpp23-notice { border-radius: var(--radius); background: var(--ok-wash); }
.cpp23-forum-form label { font-size: var(--step--1); }
.cpp23-forum-form textarea { min-height: 16rem; }

.topic-title { font-size: var(--step-3); }
.cpp23-topic-meta { font-size: var(--step--1); }

/* Replies */
.comments { margin-top: 3rem; padding-top: 1.5rem; border-top: 2px solid var(--ink); }
.comments-title { margin: 0 0 1.25rem; font-size: var(--step-1); }
.comment-list, .comment-list .children { list-style: none; margin: 0; padding: 0; }
.comment-list .children { margin-left: 1.5rem; padding-left: 1.25rem; border-left: 1px solid var(--rule); }
.comment-body { padding: 1.1rem 0; border-bottom: 1px solid var(--rule); }
.comment-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 0.25rem 0.75rem; font-size: var(--step--1); margin-bottom: 0.5rem; }
.comment-author { display: flex; align-items: center; gap: 0.6rem; }
.comment-author .avatar { border-radius: 50%; }
.comment-author .says { display: none; }
.comment-author .fn { font-style: normal; font-weight: 640; }
.comment-metadata a { color: var(--ink-soft); text-decoration: none; }
.comment-awaiting-moderation { color: var(--warn); font-size: var(--step--1); }
.comment-content > :last-child { margin-bottom: 0; }
.reply { font-size: var(--step--1); margin-top: 0.4rem; }
.comment-respond { margin-top: 2.5rem; }
.comment-reply-title { font-size: var(--step-1); margin: 0 0 0.75rem; }
.comment-reply-title small { margin-left: 0.75rem; font-size: var(--step--1); font-weight: 400; }
.comment-form label { display: block; font-size: var(--step--1); font-weight: 600; margin-bottom: 0.3rem; }
.comment-form textarea { min-height: 10rem; }
.logged-in-as, .must-log-in { font-size: var(--step--1); color: var(--ink-soft); }

/* ---------- Lists, search, 404 ---------- */

.post-list { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--rule); }
.post-item { padding: 1rem 0; border-bottom: 1px solid var(--rule); }
.post-item-title { font-weight: 640; font-size: var(--step-1); text-decoration: none; color: var(--ink); }
.post-item-excerpt { margin: 0.25em 0 0; color: var(--ink-soft); font-size: var(--step--1); }
.nav-links { display: flex; justify-content: space-between; gap: 1rem; margin-top: 1.5rem; font-size: var(--step--1); }
.search-form { display: flex; gap: 0.5rem; margin-top: 1.25rem; }
.search-form label { flex: 1; }
pre.cpp23-code.not-found-diag { color: #f0b6b0; margin-bottom: 2rem; white-space: pre-wrap; }
.not-found .page-title { margin-bottom: 0.5em; }

/* ---------- Motion ---------- */

@media (prefers-reduced-motion: reduce) {
	*, *::before, *::after { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}
@media print {
	.site-header, .site-footer, .lesson-aside, .cpp23-lesson-nav, .cpp23-ask, .comment-respond, .cpp23-copy { display: none !important; }
	.lesson-layout { display: block; }
	body { background: #fff; color: #000; }
}