:root {
	--color-paper: #f5f3ed;
	--color-white: #fffefa;
	--color-ink: #1b241f;
	--color-muted: #5b675f;
	--color-line: #d8ddd5;
	--color-sage: #e6e9e1;
	--color-orange: #cc4930;
	--color-orange-text: #b93820;
	--color-orange-hover: #ae341e;
	--color-dark: #19241f;
	--color-on-dark: #f5f3ed;
	--container: 1320px;
	--gutter: clamp(20px, 4.7vw, 76px);
	--radius-small: 5px;
	--radius-medium: 9px;
	--space-1: 4px;
	--space-2: 8px;
	--space-3: 12px;
	--space-4: 16px;
	--space-6: 24px;
	--space-8: 32px;
	--space-12: 48px;
	--space-16: 64px;
	--space-24: 96px;
	--space-32: 128px;
	--font-sans: "Archivo", arial, sans-serif;
	--font-mono: "IBM Plex Mono", ui-monospace, sfmono-regular, menlo, monospace;
	--transition: 160ms ease;
}

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

html {
	scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {

	html {
		scroll-behavior: auto;
	}

	*,
	*::before,
	*::after {
		transition-duration: 0.01ms !important;
	}
}

body {
	margin: 0;
	font-family: var(--font-sans);
	font-size: 1rem;
	line-height: 1.65;
	color: var(--color-ink);
	background: var(--color-paper);
}

.container {
	width: 100%;
	max-width: var(--container);
	margin-inline: auto;
	padding-inline: var(--gutter);
}

a {
	color: var(--color-orange-text);
	text-underline-offset: 0.18em;
}

a:hover {
	color: var(--color-orange-hover);
}

:focus-visible {
	outline: 2px solid var(--color-ink);
	outline-offset: 3px;
}

.meta-label {
	margin: 0 0 var(--space-4);
	font-family: var(--font-mono);
	font-size: 0.75rem;
	font-weight: 500;
	line-height: 1.5;
	letter-spacing: 0.06em;
	text-transform: uppercase;
	color: var(--color-muted);
}

.meta-label--on-dark {
	color: rgba(245, 243, 237, 0.65);
}

.meta-note {
	margin: var(--space-4) 0 0;
	font-family: var(--font-mono);
	font-size: 0.75rem;
	font-weight: 500;
	letter-spacing: 0.04em;
	color: var(--color-muted);
}

.display-h1 {
	margin: 0 0 var(--space-6);
	font-size: clamp(3.5rem, 7.5vw, 7.75rem);
	font-weight: 600;
	line-height: 0.94;
	letter-spacing: -0.055em;
	max-width: 14ch;
}

.display-h2 {
	margin: 0 0 var(--space-8);
	font-size: clamp(2.8rem, 5vw, 5.25rem);
	font-weight: 600;
	line-height: 1.02;
	letter-spacing: -0.045em;
	max-width: 18ch;
}

.display-h2--on-dark {
	color: var(--color-on-dark);
	max-width: 16ch;
}

.lead {
	margin: 0 0 var(--space-8);
	font-size: clamp(1.125rem, 2vw, 1.375rem);
	line-height: 1.5;
	max-width: 32ch;
	color: var(--color-muted);
}

.lead--center {
	max-width: 28ch;
	margin-inline: auto;
	text-align: center;
}

.section-index {
	margin: 0 0 var(--space-4);
	font-family: var(--font-mono);
	font-size: 0.75rem;
	font-weight: 500;
	letter-spacing: 0.06em;
	text-transform: uppercase;
	color: var(--color-muted);
}

.section {
	padding-block: clamp(64px, 10vw, 128px);
}

/* Header */
.site-header {
	position: sticky;
	top: 0;
	z-index: 50;
	background: var(--color-paper);
	border-bottom: 1px solid transparent;
}

.site-header.is-scrolled,
.site-header {
	border-bottom-color: var(--color-line);
}

.site-header__inner {
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: var(--space-6);
	min-height: 76px;
}

.wordmark {
	display: flex;
	align-items: center;
	gap: var(--space-3);
	text-decoration: none;
	color: var(--color-ink);
}

.wordmark__mark {
	display: block;
	width: 52px;
	height: 52px;
	flex-shrink: 0;
}

.wordmark__text {
	font-weight: 600;
	font-size: 1.125rem;
	letter-spacing: -0.02em;
}

.wordmark__by {
	font-family: var(--font-mono);
	font-size: 0.6875rem;
	font-weight: 500;
	color: var(--color-muted);
	padding-left: var(--space-3);
	border-left: 1px solid var(--color-line);
}

.site-nav {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	justify-content: flex-end;
	gap: var(--space-4) var(--space-6);
	font-size: 0.9375rem;
}

.site-nav a {
	text-decoration: none;
	color: var(--color-muted);
}

.site-nav a:hover {
	color: var(--color-ink);
}

.site-nav__cta {
	font-weight: 600;
	color: var(--color-ink) !important;
}

.site-nav__cta span {
	display: inline-block;
	transition: transform var(--transition);
}

.site-nav__cta:hover span {
	transform: translate(2px, -2px);
}

/* Hero */
.hero {
	padding-top: clamp(var(--space-16), 8vw, var(--space-24));
	padding-bottom: var(--space-12);
}

.hero__grid {
	display: grid;
	grid-template-columns: 1fr;
	gap: var(--space-16);
	align-items: start;
}

@media (min-width: 900px) {

	.hero__grid {
		grid-template-columns: 7fr 5fr;
		gap: var(--space-12);
	}
}

.hero__actions {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: var(--space-6) var(--space-8);
	margin-bottom: var(--space-4);
}

.btn {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	min-height: 50px;
	padding: 0 22px;
	border-radius: var(--radius-small);
	font-family: var(--font-sans);
	font-size: 1rem;
	font-weight: 600;
	text-decoration: none;
	border: none;
	cursor: pointer;
	transition: background var(--transition), color var(--transition);
}

.btn--primary {
	background: var(--color-orange);
	color: var(--color-white);
}

.btn--primary:hover {
	background: var(--color-orange-hover);
	color: var(--color-white);
}

.text-link {
	font-weight: 500;
	color: var(--color-ink);
	text-decoration: underline;
	text-underline-offset: 0.2em;
}

.text-link:hover {
	color: var(--color-orange-text);
}

.hero__rule {
	margin-top: var(--space-16);
}

.hero__rule hr {
	border: none;
	border-top: 1px solid var(--color-line);
	margin: 0 0 var(--space-3);
}

/* Checkpoint diagram */
.checkpoint-diagram {
	margin: 0;
}

.checkpoint-diagram__caption {
	font-family: var(--font-mono);
	font-size: 0.6875rem;
	color: var(--color-muted);
	margin-bottom: var(--space-3);
	text-align: right;
}

.checkpoint-diagram__panel {
	position: relative;
	background: var(--color-white);
	border: 1px solid var(--color-line);
	border-radius: var(--radius-medium);
	padding: var(--space-8) var(--space-6);
	min-height: 320px;
}

.checkpoint-rail {
	position: absolute;
	left: 28px;
	top: var(--space-8);
	bottom: var(--space-12);
	width: 2px;
}

.checkpoint-rail__line {
	position: absolute;
	inset: 0;
	background: var(--color-line);
}

.checkpoint-rail__dot {
	position: absolute;
	left: 50%;
	top: var(--stop);
	width: 12px;
	height: 12px;
	margin-left: -6px;
	margin-top: -6px;
	border-radius: 50%;
	background: var(--color-paper);
	border: 2px solid var(--color-ink);
}

.checkpoint-rail__dot--filled {
	background: var(--color-orange);
	border-color: var(--color-orange);
}

.checkpoint-records {
	list-style: none;
	margin: 0;
	padding: 0 0 0 48px;
	display: flex;
	flex-direction: column;
	gap: var(--space-8);
}

.checkpoint-records__index {
	display: block;
	font-size: clamp(2rem, 4vw, 3rem);
	font-weight: 600;
	line-height: 1;
	letter-spacing: -0.04em;
	color: var(--color-line);
}

.checkpoint-records__label {
	display: block;
	font-family: var(--font-mono);
	font-size: 0.6875rem;
	font-weight: 500;
	letter-spacing: 0.06em;
	color: var(--color-muted);
	margin-top: var(--space-2);
}

.checkpoint-records__title {
	display: block;
	font-weight: 600;
	margin-top: var(--space-1);
}

.checkpoint-records__current .checkpoint-records__index {
	color: var(--color-ink);
}

.checkpoint-restore {
	position: absolute;
	right: var(--space-6);
	bottom: var(--space-6);
	color: var(--color-orange-text);
}

.checkpoint-restore__label {
	font-family: var(--font-mono);
	font-size: 10px;
	letter-spacing: 0.08em;
	fill: currentcolor;
}

/* Idea section */
.section--idea {
	background: var(--color-sage);
}

.section__split {
	display: grid;
	grid-template-columns: 1fr;
	gap: var(--space-12);
}

@media (min-width: 900px) {

	.section__split {
		grid-template-columns: 5fr 5fr;
		gap: var(--space-16);
		align-items: start;
	}
}

.section__prose p {
	margin: 0 0 var(--space-4);
	max-width: 65ch;
	color: var(--color-muted);
}

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

/* Workflow */
.workflow-steps {
	list-style: none;
	margin: var(--space-12) 0 0;
	padding: 0;
	display: grid;
	grid-template-columns: 1fr;
	gap: 0;
	border-top: 1px solid var(--color-line);
}

@media (min-width: 900px) {

	.workflow-steps {
		grid-template-columns: repeat(3, 1fr);
		border-top: none;
		border-left: 1px solid var(--color-line);
	}
}

.workflow-steps li {
	padding: var(--space-8) var(--space-6);
	border-bottom: 1px solid var(--color-line);
	position: relative;
}

@media (min-width: 900px) {

	.workflow-steps li {
		border-bottom: none;
		border-right: 1px solid var(--color-line);
		padding-top: var(--space-12);
	}

	.workflow-steps li::before {
		content: "";
		position: absolute;
		top: 0;
		left: var(--space-6);
		width: 10px;
		height: 10px;
		margin-top: -5px;
		border-radius: 50%;
		background: var(--color-paper);
		border: 2px solid var(--color-ink);
		box-shadow: 0 0 0 4px var(--color-paper);
	}
}

.workflow-steps__num {
	font-family: var(--font-mono);
	font-size: 0.75rem;
	font-weight: 500;
	letter-spacing: 0.06em;
	color: var(--color-muted);
	display: block;
	margin-bottom: var(--space-4);
}

.workflow-steps h3 {
	margin: 0 0 var(--space-3);
	font-size: 1.5rem;
	font-weight: 600;
	line-height: 1.18;
}

.workflow-steps p {
	margin: 0;
	color: var(--color-muted);
	max-width: 28ch;
}

.workflow-note {
	margin: var(--space-8) 0 0;
	padding-top: var(--space-6);
	border-top: 1px solid var(--color-line);
	font-family: var(--font-mono);
	font-size: 0.8125rem;
	color: var(--color-muted);
	max-width: 52ch;
}

/* Feature list */
.feature-list {
	margin: var(--space-12) 0 0;
	border-top: 1px solid var(--color-line);
}

.feature-list__row {
	display: grid;
	grid-template-columns: 1fr;
	gap: var(--space-2) var(--space-6);
	padding: var(--space-6) 0;
	border-bottom: 1px solid var(--color-line);
}

@media (min-width: 768px) {

	.feature-list__row {
		grid-template-columns: minmax(0, 2fr) minmax(0, 3fr);
		align-items: baseline;
	}
}

.feature-list__index {
	font-family: var(--font-mono);
	font-size: 0.75rem;
	color: var(--color-muted);
	margin-right: var(--space-3);
}

.feature-list dt {
	margin: 0;
	font-weight: 600;
}

.feature-list dd {
	margin: 0;
	color: var(--color-muted);
	max-width: 55ch;
}

/* Dark section */
.section--dark {
	background: var(--color-dark);
	color: var(--color-on-dark);
	padding-block: clamp(80px, 12vw, 140px);
	min-height: 65vh;
	display: flex;
	align-items: center;
}

.section--dark__lede {
	margin: 0;
	max-width: 36ch;
	color: rgba(245, 243, 237, 0.75);
	font-size: 1.125rem;
}

.dark-rail {
	position: relative;
	margin-top: var(--space-16);
	height: 48px;
	max-width: 280px;
}

.dark-rail__line {
	position: absolute;
	left: 0;
	right: 40%;
	top: 50%;
	height: 2px;
	background: var(--color-orange);
}

.dark-rail__dot {
	position: absolute;
	left: 55%;
	top: 50%;
	width: 12px;
	height: 12px;
	margin: -6px 0 0 -6px;
	border-radius: 50%;
	background: var(--color-orange);
}

.dark-rail__back {
	position: absolute;
	left: 70%;
	top: 50%;
	transform: translateY(-50%);
	font-family: var(--font-mono);
	font-size: 0.75rem;
	color: var(--color-orange);
}

/* Spec table */
.spec-table {
	width: 100%;
	border-collapse: collapse;
	margin-top: var(--space-12);
}

.spec-table th,
.spec-table td {
	padding: var(--space-4) 0;
	border-bottom: 1px solid var(--color-line);
	text-align: left;
	vertical-align: top;
}

.spec-table th {
	width: 38%;
	font-family: var(--font-mono);
	font-size: 0.8125rem;
	font-weight: 500;
	color: var(--color-muted);
}

.spec-table td {
	color: var(--color-muted);
	max-width: 48ch;
}

.trust-note {
	margin: var(--space-8) 0 0;
	padding: var(--space-6);
	background: var(--color-sage);
	border-radius: var(--radius-small);
	font-size: 0.9375rem;
	color: var(--color-muted);
	max-width: 60ch;
}

code {
	font-family: var(--font-mono);
	font-size: 0.875em;
	background: var(--color-sage);
	padding: 0.1em 0.35em;
	border-radius: 3px;
}

/* FAQ */
.section--faq {
	background: var(--color-white);
}

.faq-list {
	margin-top: var(--space-12);
	border-top: 1px solid var(--color-line);
}

.faq-item {
	border-bottom: 1px solid var(--color-line);
}

.faq-item summary {
	padding: var(--space-6) 0;
	font-weight: 600;
	cursor: pointer;
	list-style: none;
	min-height: 44px;
	display: flex;
	align-items: center;
}

.faq-item summary::-webkit-details-marker {
	display: none;
}

.faq-item summary::after {
	content: "+";
	margin-left: auto;
	font-family: var(--font-mono);
	font-weight: 500;
	color: var(--color-muted);
}

.faq-item[open] summary::after {
	content: "−";
}

.faq-item p {
	margin: 0 0 var(--space-6);
	padding-bottom: var(--space-4);
	color: var(--color-muted);
	max-width: 65ch;
}

/* Changelog */
.changelog__body {
	margin-top: var(--space-8);
	padding: var(--space-8);
	background: var(--color-white);
	border: 1px solid var(--color-line);
	border-radius: var(--radius-medium);
}

.changelog__body h3 {
	font-size: 1.125rem;
	font-weight: 600;
	margin: var(--space-8) 0 var(--space-3);
	padding-top: var(--space-6);
	border-top: 1px solid var(--color-line);
}

.changelog__body h3:first-child {
	margin-top: 0;
	padding-top: 0;
	border-top: none;
}

.changelog__body ul {
	margin: 0 0 var(--space-4);
	padding-left: 1.25rem;
	color: var(--color-muted);
}

.changelog__body li {
	margin-bottom: var(--space-2);
}

/* Closing */
.section--closing {
	text-align: center;
	padding-bottom: var(--space-24);
}

.section--closing__inner {
	display: flex;
	flex-direction: column;
	align-items: center;
	gap: var(--space-6);
}

/* Footer */
.site-footer {
	border-top: 1px solid var(--color-line);
	padding-block: var(--space-12);
	background: var(--color-paper);
}

.site-footer__inner {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	justify-content: space-between;
	gap: var(--space-6);
}

.site-footer__brand {
	margin: 0;
}

.site-footer__by {
	font-family: var(--font-mono);
	font-size: 0.75rem;
	font-weight: 500;
	color: var(--color-muted);
}

.site-footer__nav {
	display: flex;
	flex-wrap: wrap;
	gap: var(--space-4) var(--space-6);
	font-size: 0.9375rem;
}

.site-footer__nav a {
	text-decoration: none;
	color: var(--color-muted);
}

.site-footer__nav a:hover {
	color: var(--color-ink);
}

.site-footer__dev {
	font-family: var(--font-mono);
	font-size: 0.75rem;
}

/* Mobile nav simplification */
@media (max-width: 767px) {

	.wordmark__by {
		display: none;
	}

	.wordmark__mark {
		width: 40px;
		height: 40px;
	}

	.site-nav a:not(.site-nav__cta) {
		display: none;
	}

	.display-h1 {
		font-size: clamp(3.25rem, 14vw, 4.125rem);
	}

	.checkpoint-diagram__panel {
		min-height: auto;
	}
}