:root {
	color-scheme: light;
	font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
	--page-width: 76rem;
	--ink: #172033;
	--muted-ink: #586174;
	--page-background: #F5F2EA;
	--paper: #FFFDF8;
	--panel: #ECE8DC;
	--accent: #314F8F;
	--accent-dark: #233A6B;
	--border: #D5CFC1;
	--shadow: 0 0.8rem 2.2rem rgb(36 42 55 / 0.12);

	/* Main appearance controls. */
	/* --front-h1-size: clamp(2.5rem, 5.5vw, 4.25rem); */
	/* --hero-spacing: clamp(2.75rem, 6vw, 4.75rem); */
	/* --section-spacing: clamp(3.25rem, 6vw, 5rem); */
	--front-h1-size: clamp(2.3rem, 4.8vw, 3.75rem);
	--front-h2-size: clamp(1.75rem, 3vw, 2.35rem);
	--hero-spacing: clamp(2.25rem, 4vw, 3.5rem);
	--section-spacing: clamp(2.75rem, 5vw, 4rem);
	}

* {
	box-sizing: border-box;
}

html {
	scroll-behavior: smooth;
}

body {
	margin: 0;
	background: var(--page-background);
	color: var(--ink);
	font-size: 1.04rem;
	line-height: 1.7;
}

a {
	color: var(--accent);
}

a:hover {
	color: var(--accent-dark);
}

.site-header {
	border-bottom: 1px solid rgb(213 207 193 / 0.9);
	background: rgb(245 242 234 / 0.96);
}

.header-content {
	width: min(calc(100% - 2rem), var(--page-width));
	min-height: 4.5rem;
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 2rem;
	margin-inline: auto;
}

.site-name {
	color: var(--ink);
	font-size: 1.15rem;
	font-weight: 750;
	letter-spacing: 0.01em;
	text-decoration: none;
}

nav {
	display: flex;
	flex-wrap: wrap;
	gap: 1.4rem;
}

nav a {
	color: var(--muted-ink);
	font-size: 0.92rem;
	font-weight: 650;
	text-decoration: none;
}

main {
	overflow: hidden;
}

.hero,
.content-section,
.play-banner {
	width: min(calc(100% - 2rem), var(--page-width));
	margin-inline: auto;
}

.hero {
	display: grid;
	grid-template-columns: minmax(0, 1.05fr) minmax(19rem, 0.95fr);
	align-items: center;
	gap: clamp(2rem, 5vw, 4rem);
	padding-block: var(--hero-spacing);
}

.eyebrow,
.card-eyebrow {
	margin: 0 0 0.6rem;
	color: var(--accent);
	font-size: 0.78rem;
	font-weight: 800;
	letter-spacing: 0.14em;
	text-transform: uppercase;
}

h1,
h2,
h3,
p {
	text-wrap: pretty;
}

h1 {
	max-width: 14ch;
	margin: 0;
	font-size: var(--front-h1-size);
	line-height: 1.02;
	letter-spacing: -0.045em;
}

h2 {
	margin: 0 0 1rem;
	font-size: var(--front-h2-size);
	line-height: 1.15;
	letter-spacing: -0.025em;
}

h3 {
	margin: 0;
	font-size: 1.08rem;
	line-height: 1.35;
}

p {
	margin-block: 1rem;
}

.hero-summary {
	max-width: 40rem;
	margin: 1.4rem 0 0;
	color: var(--muted-ink);
	font-size: clamp(1.12rem, 2.2vw, 1.3rem);
	line-height: 1.55;
}

.hero-actions {
	display: flex;
	flex-wrap: wrap;
	gap: 0.8rem;
	margin-top: 1.6rem;
}

.primary-action,
.secondary-action {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	min-height: 3rem;
	border-radius: 999px;
	padding: 0.65rem 1.15rem;
	font-weight: 750;
	text-decoration: none;
}

.primary-action {
	background: var(--accent);
	color: white;
}

.primary-action:hover,
.primary-action:focus-visible {
	background: var(--accent-dark);
	color: white;
}

.secondary-action {
	border: 1px solid var(--border);
	background: var(--paper);
	color: var(--ink);
}

.secondary-action:hover,
.secondary-action:focus-visible {
	border-color: var(--accent);
	color: var(--accent);
}

a:focus-visible {
	outline: 3px solid #87A8E6;
	outline-offset: 3px;
}

.history-note {
	max-width: 39rem;
	margin: 1.25rem 0 0;
	color: var(--muted-ink);
	font-size: 0.93rem;
}

.puzzle-figure {
	margin: 0;
}

.puzzle-image {
	display: block;
	width: 100%;
	height: auto;
	border: 1px solid #2D3442;
	background: #11151E;
	box-shadow: 0 0 0 0.35rem #11151E, var(--shadow);
}

.solution-figure
{
	max-width: 32rem;
	margin: 2.4rem;
	margin-inline: auto;
}

figcaption {
	margin-top: 0.85rem;
	color: var(--muted-ink);
	font-size: 0.9rem;
	line-height: 1.45;
	text-align: center;
}

.content-section {
	padding-block: var(--section-spacing);
}

.alternate-section {
	position: relative;
}

.alternate-section::before {
	content: "";
	position: absolute;
	z-index: -1;
	top: 0;
	bottom: 0;
	left: 50%;
	width: 100vw;
	transform: translateX(-50%);
	background: var(--panel);
}

.section-heading {
	max-width: 47rem;
	margin-bottom: 2.1rem;
}

.section-heading > p:last-child {
	color: var(--muted-ink);
	font-size: 1.06rem;
}

.rules-layout {
	display: grid;
	grid-template-columns: minmax(0, 1fr) minmax(17rem, 0.7fr);
	align-items: center;
	gap: clamp(2rem, 5vw, 4rem);
}

.rules-copy p:first-child {
	margin-top: 0;
}

.rules-copy p:last-child {
	margin-bottom: 0;
}

.feature-grid,
.detail-grid,
.group-grid {
	display: grid;
	gap: 1rem;
}

.feature-grid,
.detail-grid {
	grid-template-columns: repeat(3, minmax(0, 1fr));
}

.feature-card,
.detail-card,
.group-grid article {
	border: 1px solid var(--border);
	border-radius: 0.8rem;
	padding: 1.3rem 1.4rem;
	background: var(--paper);
}

.feature-card p,
.detail-card p,
.group-grid p {
	margin-bottom: 0;
	color: var(--muted-ink);
}

.feature-symbol {
	margin-bottom: 0.8rem;
	color: var(--accent);
	font-size: 1.8rem;
	line-height: 1;
}

.group-grid {
	grid-template-columns: repeat(4, minmax(0, 1fr));
}

.group-number {
	display: grid;
	width: 2.2rem;
	height: 2.2rem;
	place-items: center;
	margin-bottom: 1rem;
	border-radius: 50%;
	background: var(--accent);
	color: white;
	font-weight: 800;
}

.card-eyebrow {
	margin-bottom: 0.7rem !important;
}

.card-link {
	display: inline-block;
	margin-top: 1rem;
	font-weight: 700;
}

.play-banner {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 1.5rem;
	margin-block: var(--section-spacing);
	border-radius: 1rem;
	padding: 1.4rem;
	background: var(--ink);
	color: white;
}

.play-banner p,
.play-banner h2 {
	margin-block: 0.35rem;
}

.play-banner .eyebrow {
	color: #AFC6F2;
}

.play-banner .primary-action {
	flex: 0 0 auto;
	background: white;
	color: var(--ink);
}

.play-banner .primary-action:hover {
	background: #E9EDF6;
	color: var(--ink);
}

footer {
	border-top: 1px solid var(--border);
	padding: 2rem 1rem;
	color: var(--muted-ink);
	font-size: 0.9rem;
	text-align: center;
}

footer p {
	margin: 0;
}

@media (max-width: 820px) {
	.hero,
	.rules-layout {
		grid-template-columns: 1fr;
	}

	.hero-figure {
		width: min(100%, 36rem);
	}

	.feature-grid,
	.detail-grid {
		grid-template-columns: 1fr;
	}

	.group-grid {
		grid-template-columns: repeat(2, minmax(0, 1fr));
	}
}

@media (max-width: 600px) {
	.header-content {
		min-height: auto;
		align-items: flex-start;
		flex-direction: column;
		padding-block: 0.9rem;
	}

	nav {
		gap: 0.5rem 1rem;
	}

	.hero {
		padding-top: 2.8rem;
	}

	.group-grid {
		grid-template-columns: 1fr;
	}

	.play-banner {
		align-items: flex-start;
		flex-direction: column;
	}
}

@media (prefers-reduced-motion: reduce) {
	html {
		scroll-behavior: auto;
	}
}