$scale: 3;
$ease: cubic-bezier(0.32, 0.72, 0.22, 1);

:root {
	--bg: #fff;
	--ink: #17130e;
	--ink-soft: #71695c;
	--line: #e4ded3;
	--card: #ffffff;
	--accent: #7c3aed;
	--ease: $ease;
	--dur: 0.32s;
	--radius: 0.75rem;
}

.navbar {
	position: sticky;
	top: 0;
	z-index: 20;
	isolation: isolate;
	background: var(--card);
	border-bottom: 1px solid var(--line);

	&::after {
		content: "";
		position: absolute;
		top: 100%;
		left: 0;
		width: 100%;
		height: 0.5rem;
	}
}

.navbar__row {
	position: relative;
	max-width: 72rem;
	margin: 0 auto;
	display: flex;
	align-items: center;
	gap: 0.9rem;
	padding: 0.55rem 1.25rem 0.45rem;
}

.navbar__brand {
	color: var(--ink);
	text-decoration: none;
	font-weight: 650;
	letter-spacing: -0.02em;
	font-size: 0.95rem;
}

.navbar {
	--pill-x: $refer[left](@navitemhome);
	--pill-y: $refer[top](@navitemhome);
	--pill-w: $refer[width](@navitemhome);
	--pill-h: $refer[height](@navitemhome);
}

@each $item in naviteminterpolate navitemrefer navitempredict navitemroute {
	.navbar:has([data-muddle-anchor="#{$item}"][aria-current="page"]) {
		--pill-x: $refer[left](@#{$item});
		--pill-y: $refer[top](@#{$item});
		--pill-w: $refer[width](@#{$item});
		--pill-h: $refer[height](@#{$item});
	}
}

.navbar__pill {
	position: absolute;
	left: calc(var(--pill-x) - $refer[left](@navbar));
	top: calc(var(--pill-y) - $refer[top](@navbar));
	width: var(--pill-w);
	height: var(--pill-h);
	box-sizing: border-box;
	border: 1px solid var(--accent);
	border-radius: 999px;
	pointer-events: none;
	transition: left var(--dur) $ease, top var(--dur) $ease, width var(--dur) $ease, height var(--dur) $ease;
}

.navbar__items {
	display: flex;
	gap: 0.15rem;
	margin-left: auto;
	list-style: none;
	scroll-behavior: smooth;
	scroll-snap-type: x proximity;
	overscroll-behavior-inline: contain;
}

.navbar__item {
	display: block;
	scroll-snap-align: center;
	padding: 0.3rem 0.62rem;
	border-radius: 0.55rem;
	color: var(--ink-soft);
	text-decoration: none;
	font-size: 0.82rem;
	transition: color var(--dur) $ease;

	&[aria-current="page"] {
		color: var(--ink);
		font-weight: 620;
	}

	&:hover {
		color: var(--ink);
	}
}

:root {
	--muddle-predict-duration: 300ms;
	--muddle-predict-easing: $ease;
}

.navbar {
	--ribbon-x: calc($refer[left](@navitemhome) + $refer[width](@navitemhome) / 2 - $refer[left](@navbar) - ($refer[width](@panehome) + 1.6rem + 2px) / 2);
	--ribbon-w: calc($refer[width](@panehome) + 1.6rem + 2px);
	--ribbon-h: calc($refer[height](@panehome) + 1.24rem + 2px);
	--pointer-x: calc($refer[left](@navitemhome) + $refer[width](@navitemhome) / 2 - $refer[left](@navbar) - var(--ribbon-x));
}

@each $id in home interpolate refer predict route {
	.navbar:has([data-muddle-anchor="navitem#{$id}"]:hover) .navbar__ribbon,
	.navbar:has([data-muddle-anchor="navitem#{$id}"]:focus-visible) .navbar__ribbon {
		--ribbon-x: calc($refer[left](@navitem#{$id}) + $refer[width](@navitem#{$id}) / 2 - $refer[left](@navbar) - ($refer[width](@pane#{$id}) + 1.6rem + 2px) / 2);
		--ribbon-w: calc($refer[width](@pane#{$id}) + 1.6rem + 2px);
		--ribbon-h: calc($refer[height](@pane#{$id}) + 1.24rem + 2px);
		--pointer-x: calc($refer[left](@navitem#{$id}) + $refer[width](@navitem#{$id}) / 2 - $refer[left](@navbar) - var(--ribbon-x));
	}
}

.navbar__ribbon {
	position: fixed;
	top: calc($refer[top](@navbar) + $refer[height](@navbar));
	left: calc($refer[left](@navbar) + var(--ribbon-x));
	width: var(--ribbon-w);
	height: var(--ribbon-h);
	max-width: min(24rem, calc(100vw - 3rem));
	box-sizing: border-box;
	overflow: clip;
	clip-path: inset(-10px 0 0 round 0.6rem);
	border: 1px solid var(--line);
	border-radius: 0.6rem;
	background: var(--card);
	box-shadow: 0 14px 30px -20px rgba(23, 19, 14, 0.45);
	opacity: 0;
	visibility: visible;
	transform: translateY(6px);
	pointer-events: auto;
	z-index: 30;
	@predict left top width height opacity transform visibility;
	@measure;

	&::before,
	&::after {
		content: "";
		position: absolute;
		top: -6px;
		left: calc(var(--pointer-x) - 6px);
		width: 12px;
		height: 12px;
		transform: rotate(45deg);
		pointer-events: none;
		@predict transform;
	}

	&::before {
		z-index: 1;
		background: var(--card);
		border-left: 1px solid var(--line);
		border-top: 1px solid var(--line);
	}

	&::after {
		z-index: 2;
		width: 8px;
		height: 8px;
		top: -5px;
		left: calc(var(--pointer-x) - 4px);
		background: var(--card);
	}
}


.navbar:has(.navbar__item:hover) .navbar__ribbon,
.navbar:has(.navbar__ribbon:hover) .navbar__ribbon,
.navbar:has(.navbar__items:focus-within) .navbar__ribbon {
	opacity: 1;
	visibility: visible;
	transform: translateY(0);
	pointer-events: auto;
}

.navbar__pane {
	position: absolute;
	top: 0.62rem;
	left: 0.8rem;
	width: max-content;
	max-width: 24rem;
	margin: 0;
	font-size: 0.8rem;
	line-height: 1.5;
	color: var(--ink-soft);
	opacity: 0;
	visibility: hidden;
	transition: opacity var(--dur) $ease, visibility var(--dur) step-end;
}

@each $id in home interpolate refer predict route {
	.navbar:has([data-muddle-anchor="navitem#{$id}"]:hover) [data-muddle-anchor="pane#{$id}"],
	.navbar:has([data-muddle-anchor="navitem#{$id}"]:focus-visible) [data-muddle-anchor="pane#{$id}"] {
		opacity: 1;
		visibility: visible;
		animation: fadein var(--dur) $ease;
	}
}

@keyframes fadein {
	from {
		opacity: 0;
	}
	to {
		opacity: 1;
	}
}

.navbar__pane-cover {
	margin: 0;

	img {
		width: 3rem;
		height: 3rem;
		border-radius: 0.45rem;
		border: 1px solid var(--line);
		display: block;
		background: var(--bg);
	}
}

.navbar__pane--album {
	width: min(19rem, calc(100vw - 4rem));
	max-height: min(20rem, calc(100vh - 6rem));
	overflow-y: auto;
	overscroll-behavior: contain;
	scrollbar-width: thin;
	scrollbar-color: var(--line) transparent;
	padding-right: 0.2rem;
}

.navbar__album-header {
	display: grid;
	grid-template-columns: 3rem minmax(0, 1fr);
	gap: 0.7rem;
	align-items: center;
}

.navbar__pane-head {
	margin: 0;
	font-size: 0.8rem;
	font-weight: 600;
	color: var(--ink);
}

.navbar__album-date {
	display: block;
	margin-top: 0.18rem;
	font-size: 0.7rem;
	color: var(--ink-soft);
	font-variant-numeric: tabular-nums;
}

.navbar__tracks {
	margin: 0.7rem 0 0;
	padding: 0;
	list-style: none;
	font-size: 0.74rem;
	line-height: 1.6;
	color: var(--ink-soft);
	counter-reset: track;

	li {
		display: grid;
		grid-template-columns: minmax(0, 1fr) auto;
		gap: 0.8rem;
		align-items: baseline;
		counter-increment: track;
		border-top: 1px solid color-mix(in srgb, var(--line) 72%, transparent);
		padding: 0.28rem 0;

		span:first-child::before {
			content: counter(track, decimal-leading-zero);
			display: inline-block;
			width: 1.65rem;
			color: color-mix(in srgb, var(--ink-soft) 62%, transparent);
			font-variant-numeric: tabular-nums;
		}
	}
}

.navbar__track-duration {
	margin-left: 0;
	color: color-mix(in srgb, var(--ink-soft) 70%, transparent);
	font-variant-numeric: tabular-nums;
}

body {
	margin: 0;
	background: var(--bg);
	color: var(--ink);
	font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
	-webkit-font-smoothing: antialiased;
}

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

.page {
	max-width: 72rem;
	margin: 0 auto;
	padding: 2.2rem 1.25rem 3rem;
}

.card {
	background: var(--card);
	border: 1px solid var(--line);
	border-radius: var(--radius);
	padding: 1.15rem 1.25rem;
}

.demo-hero {
	max-width: 44rem;
	margin: 0.8rem 0 2rem;

	h1 {
		margin: 0;
		font-size: clamp(1.9rem, 4vw, 2.9rem);
		letter-spacing: -0.03em;
	}

	p {
		margin: 0.85rem 0 0;
		max-width: 34rem;
		color: var(--ink-soft);
		line-height: 1.65;

		kbd {
			font-size: 0.72rem;
			background: var(--card);
			border: 1px solid var(--line);
			border-bottom-width: 2px;
			border-radius: 0.3rem;
			padding: 0.05rem 0.3rem;
		}
	}
}

.demo-grid {
	display: grid;
	grid-template-columns: repeat(auto-fit, minmax(13rem, 1fr));
	gap: 0.8rem;

	a {
		display: block;
		height: 100%;
		text-decoration: none;
		color: inherit;
	}

	.card {
		height: 100%;
	}

	strong {
		display: block;
		margin-bottom: 0.3rem;
		font-size: 0.9rem;
	}

	span {
		font-size: 0.8rem;
		color: var(--ink-soft);
		line-height: 1.5;
	}
}

.demo-aside {
	margin-top: 1rem;
	font-size: 0.8rem;
	color: var(--ink-soft);

	code {
		background: var(--card);
		border: 1px solid var(--line);
		border-radius: 0.3rem;
		padding: 0.05rem 0.3rem;
	}
}

.demo-feature {
	max-width: 44rem;

	h1 {
		margin: 0.6rem 0 0;
		font-size: clamp(1.7rem, 3.4vw, 2.4rem);
		letter-spacing: -0.02em;
	}

	nav {
		display: flex;
		flex-wrap: wrap;
		gap: 0.35rem;
		margin-top: 1.4rem;

		a {
			font-size: 0.8rem;
			text-decoration: none;
			border: 1px solid var(--line);
			border-radius: 999px;
			background: var(--card);
			color: var(--ink-soft);
			padding: 0.2rem 0.65rem;
			transition: color var(--dur) $ease, border-color var(--dur) $ease;

			&:hover {
				color: var(--ink);
				border-color: var(--ink);
			}

			&[aria-current="page"] {
				color: var(--card);
				border-color: var(--ink);
				background: var(--ink);
			}
		}
	}

	.demo-grid {
		margin-top: 2rem;
	}
}

.demo-meter {
	display: flex;
	flex-direction: column;
	gap: 0.45rem;
	margin-top: 1.2rem;

	i {
		display: block;
		height: 0.55rem;
		border-radius: 999px;
		background: color-mix(in srgb, var(--accent) 18%, var(--card));
		border: 1px solid color-mix(in srgb, var(--accent) 35%, var(--line));
	}
}

.demo-meter--one i {
	width: #{($scale * 2) * 2}rem;
}

.demo-meter--two i {
	width: #{$scale * 2.5}rem;
}

.demo-meter--three i {
	width: calc($scale * 3rem);
}

.demo-intro {
	margin-top: 1.6rem;
	max-width: 44rem;
}

.demo-intro__stage {
	--intro-tint: var(--accent);
	--intro-x: calc($refer[left](@introtopicscaffold) + $refer[width](@introtopicscaffold) / 2 - $refer[left](@introstage));
	--intro-w: calc($refer[width](@intropanescaffold) + 2rem);
	--intro-h: calc($refer[height](@intropanescaffold) + 1.4rem);
	position: relative;
	display: flex;
	flex-direction: column;
	gap: 0.9rem;
	padding: 0.9rem 1rem 1.5rem;
	border: 1px solid var(--line);
	border-radius: 1rem;
	background:
		linear-gradient(to bottom, color-mix(in srgb, var(--intro-tint) 16%, transparent) 0%, transparent 60%),
		var(--card);
}

.demo-intro__topics {
	display: flex;
	flex-wrap: wrap;
	gap: 0.4rem;
	list-style: none;
	margin: 0;
	padding: 0;
}

.demo-intro__topic {
	display: inline-flex;
	font: inherit;
	font-size: 0.8rem;
	padding: 0.28rem 0.7rem;
	border: 1px solid var(--line);
	border-radius: 999px;
	background: transparent;
	color: var(--ink-soft);
	cursor: pointer;
	transition: color var(--dur) $ease, border-color var(--dur) $ease, background-color var(--dur) $ease;

	&:hover {
		color: var(--ink);
		border-color: var(--ink);
	}

	.demo-intro__toggle:checked + & {
		color: var(--card);
		background: var(--ink);
		border-color: var(--ink);
	}

	&:focus-visible {
		outline: 2px solid var(--intro-tint);
		outline-offset: 1px;
	}
}

.demo-intro__toggle {
	position: absolute;
	opacity: 0;
	pointer-events: none;
}

.demo-intro__panel {
	position: absolute;
	left: max(0.75rem, calc(var(--intro-x) - var(--intro-w) / 2));
	top: calc($refer[top](@introtopicscaffold) - $refer[top](@introstage) + $refer[height](@introtopicscaffold) + 0.75rem);
	width: var(--intro-w);
	height: var(--intro-h);
	box-sizing: border-box;
	overflow: hidden;
	border: 1px solid color-mix(in srgb, var(--intro-tint) 45%, var(--line));
	border-radius: 0.7rem;
	background: var(--card);
	box-shadow: 0 12px 26px -18px rgba(23, 19, 14, 0.5);
	opacity: 0;
	visibility: hidden;
	transform: translateY(5px);
	pointer-events: none;
	@predict left top width height opacity transform visibility;
	@measure;
}

.demo-intro__note {
	position: absolute;
	left: 1rem;
	top: 0.7rem;
	width: max-content;
	max-width: 24rem;
	margin: 0;
	font-size: 0.78rem;
	line-height: 1.55;
	color: var(--ink-soft);
	opacity: 0;
	visibility: hidden;
	@measure;
}

.demo-intro__stage:has(.demo-intro__topics:focus-within) .demo-intro__panel {
	opacity: 1;
	visibility: visible;
	transform: translateY(0);
}

.demo-intro__stage:has([data-tint="violet"]:hover),
.demo-intro__stage:has(#intro-step-scaffold:checked) {
	--intro-tint: #7c3aed;
}

.demo-intro__stage:has([data-tint="rose"]:hover),
.demo-intro__stage:has(#intro-step-relations:checked) {
	--intro-tint: #e11d48;
}

.demo-intro__stage:has([data-tint="sky"]:hover),
.demo-intro__stage:has(#intro-step-predict:checked) {
	--intro-tint: #0284c7;
}

.demo-intro__stage:has([data-tint="amber"]:hover),
.demo-intro__stage:has(#intro-step-momentum:checked) {
	--intro-tint: #d97706;
}

@each $id in scaffold relations predict momentum {
	.demo-intro__stage:has([data-muddle-anchor="introtopic#{$id}"]:hover) .demo-intro__panel,
	.demo-intro__stage:has(#intro-step-#{$id}:checked) .demo-intro__panel {
		--intro-x: calc($refer[left](@introtopic#{$id}) + $refer[width](@introtopic#{$id}) / 2 - $refer[left](@introstage));
		--intro-w: calc($refer[width](@intropane#{$id}) + 2rem);
		--intro-h: calc($refer[height](@intropane#{$id}) + 1.4rem);
	}
}

@each $id in scaffold relations predict momentum {
	.demo-intro__stage:has([data-muddle-anchor="introtopic#{$id}"]:hover) [data-muddle-anchor="intropane#{$id}"],
	.demo-intro__stage:has(#intro-step-#{$id}:checked) [data-muddle-anchor="intropane#{$id}"],
	.demo-intro__stage:has([data-muddle-anchor="introtopic#{$id}"]:focus-visible) [data-muddle-anchor="intropane#{$id}"] {
		opacity: 1;
		visibility: visible;
	}
}

@each $id in scaffold relations predict momentum {
	.demo-intro__stage:has(.demo-intro__topic:hover):has(#intro-step-#{$id}:checked) [data-muddle-anchor="intropane#{$id}"] {
		opacity: 0;
		visibility: hidden;
	}

	.demo-intro__stage:has([data-muddle-anchor="introtopic#{$id}"]:hover) [data-muddle-anchor="intropane#{$id}"] {
		opacity: 1;
		visibility: visible;
	}
}

.demo-intro__stage:has(.demo-intro__toggle:checked) .demo-intro__panel {
	opacity: 1;
	visibility: visible;
	transform: translateY(0);
	pointer-events: auto;
}

.prose {
	max-width: 40rem;
	line-height: 1.7;
	font-size: 0.95rem;
	margin-top: 1.1rem;
}

.demo-footer {
	max-width: 72rem;
	margin: 0 auto;
	padding: 1rem 1.25rem 2rem;
	border-top: 1px solid var(--line);
	font-size: 0.75rem;
	color: var(--ink-soft);
}

@media (max-width: 48rem) {
	.navbar__row {
		flex-wrap: wrap;
		padding: 0.5rem 1rem 0.35rem;
	}

	.navbar__brand {
		margin-right: auto;
	}

	.navbar__items {
		margin-left: 0;
		order: 3;
		width: 100%;
		gap: 0.05rem;
		overflow-x: auto;
		scrollbar-width: none;
		padding-bottom: 0.25rem;
	}

	.navbar__item {
		font-size: 0.72rem;
		padding: 0.25rem 0.5rem;
		white-space: nowrap;
	}

	.navbar__ribbon {
		max-width: calc(100vw - 1.5rem);
	}

	.page {
		padding: 1.4rem 1rem 2.2rem;
	}

	.demo-hero h1 {
		font-size: clamp(1.6rem, 7vw, 2.2rem);
	}

	.demo-intro__stage {
		padding: 0.8rem 0.8rem 1.2rem;
	}

	.demo-intro__note {
		max-width: calc(100vw - 5rem);
	}

	.demo-intro__panel {
		max-width: calc(100vw - 2rem);
	}

	.demo-meter i {
		height: 0.5rem;
	}

	.navbar__pane-cover img {
		width: 2.4rem;
		height: 2.4rem;
	}

	.navbar__pane-head {
		font-size: 0.72rem;
	}

	.navbar__tracks {
		font-size: 0.68rem;
	}
}