/* ============================================
   Scroll-Driven Animation Demo - Demo Styles
   ============================================ */

/* Progress Bar */
.progress-bar {
	position: fixed;
	top: 0;
	left: 0;
	right: 0;
	height: 4px;
	background: rgba(255, 255, 255, 0.1);
	z-index: 100;
}

.progress-bar__fill {
	height: 100%;
	background: linear-gradient(90deg, var(--accent), var(--accent-2));
	transform-origin: left center;
	transform: scaleX(0);
}

/* Page Header */
.page-header {
	padding: 80px 0 40px;
}

.page-header__back {
	display: inline-flex;
	align-items: center;
	gap: 8px;
	margin-bottom: 24px;
	font-size: 14px;
	color: var(--text-muted);
}

.page-header__back:hover {
	color: var(--text);
}

.page-header__title {
	margin-bottom: 12px;
}

.page-header__desc {
	max-width: 600px;
	margin-bottom: 16px;
}

/* ============================================
   Hero Section
   ============================================ */
.hero {
	position: relative;
	min-height: 250vh;
}

.hero__sticky {
	position: sticky;
	top: 0;
	height: 100vh;
	display: flex;
	align-items: center;
	justify-content: center;
	overflow: hidden;
}

.hero__frame {
	position: relative;
	width: min(900px, 90vw);
	height: min(500px, 70vh);
	border-radius: var(--radius-xl);
	overflow: hidden;
	box-shadow: 0 40px 100px rgba(0, 0, 0, 0.5);
}

.hero__layer {
	position: absolute;
	inset: 0;
	display: flex;
	flex-direction: column;
	align-items: center;
	justify-content: center;
	text-align: center;
	padding: 40px;
}

.hero__base {
	background: linear-gradient(135deg, #1e3a5f 0%, #0f172a 100%);
}

.hero__base::before {
	content: "";
	position: absolute;
	inset: 0;
	background: radial-gradient(circle at 30% 30%, rgba(59, 130, 246, 0.3), transparent 60%);
}

.hero__cover {
	background: linear-gradient(180deg, #0f172a 0%, #1e293b 100%);
	transform: translateY(0);
	will-change: transform;
}

.hero__layer h2 {
	position: relative;
	font-size: clamp(28px, 5vw, 44px);
	margin-bottom: 16px;
}

.hero__layer p {
	position: relative;
	font-size: 16px;
	max-width: 400px;
}

/* ============================================
   Features Section
   ============================================ */
.features {
	padding: var(--section-gap) 0;
}

.features__header {
	text-align: center;
	margin-bottom: 48px;
}

.features__grid {
	display: grid;
	grid-template-columns: repeat(auto-fit, minmax(min(280px, 100%), 1fr));
	gap: 24px;
}

.feature-card {
	background: var(--surface);
	border: 1px solid rgba(148, 163, 184, 0.1);
	border-radius: var(--radius-lg);
	padding: 32px;
	/* Initial state - hidden */
	opacity: 0;
	transform: translateY(60px);
	will-change: transform, opacity;
}

.feature-card__icon {
	width: 56px;
	height: 56px;
	display: flex;
	align-items: center;
	justify-content: center;
	font-size: 28px;
	background: linear-gradient(135deg, rgba(59, 130, 246, 0.15), rgba(139, 92, 246, 0.15));
	border-radius: var(--radius-md);
	margin-bottom: 20px;
}

.feature-card h3 {
	font-size: 20px;
	margin-bottom: 12px;
}

.feature-card p {
	font-size: 15px;
	line-height: 1.6;
}

/* Feature Card Visible State */
.feature-card.is-visible {
	opacity: 1;
	transform: translateY(0);
}

/* ============================================
   Stats Section
   ============================================ */
.stats {
	padding: var(--section-gap) 0;
	background: linear-gradient(180deg, transparent, rgba(30, 41, 59, 0.3), transparent);
}

.stats__header {
	text-align: center;
	margin-bottom: 48px;
}

.stats__grid {
	display: grid;
	grid-template-columns: repeat(auto-fit, minmax(min(200px, 100%), 1fr));
	gap: 24px;
}

.stat-card {
	text-align: center;
	padding: 32px 24px;
	background: var(--surface);
	border: 1px solid rgba(148, 163, 184, 0.1);
	border-radius: var(--radius-lg);
	/* Initial state */
	opacity: 0;
	transform: scale(0.9);
	will-change: transform, opacity;
}

.stat-card__value {
	font-size: clamp(36px, 6vw, 52px);
	font-weight: 800;
	background: linear-gradient(135deg, var(--accent), var(--accent-2));
	-webkit-background-clip: text;
	-webkit-text-fill-color: transparent;
	background-clip: text;
	margin-bottom: 8px;
}

.stat-card__label {
	font-size: 15px;
	color: var(--text-muted);
}

/* Stat Card Visible State */
.stat-card.is-visible {
	opacity: 1;
	transform: scale(1);
}

/* ============================================
   Info Section (Implementation Details)
   ============================================ */
.impl-info {
	padding: var(--section-gap) 0;
}

.impl-info__grid {
	display: grid;
	grid-template-columns: repeat(auto-fit, minmax(min(300px, 100%), 1fr));
	gap: 24px;
}

.impl-info__box {
	padding: 28px;
	background: var(--surface);
	border: 1px solid rgba(148, 163, 184, 0.1);
	border-radius: var(--radius-lg);
}

.impl-info__box h3 {
	font-size: 18px;
	margin-bottom: 16px;
	display: flex;
	align-items: center;
	gap: 10px;
}

.impl-info__box h3::before {
	content: "";
	width: 4px;
	height: 20px;
	background: linear-gradient(180deg, var(--accent), var(--accent-2));
	border-radius: 2px;
}

.impl-info__box ul {
	list-style: none;
}

.impl-info__box li {
	padding: 8px 0;
	font-size: 14px;
	color: var(--text-muted);
	border-bottom: 1px solid rgba(148, 163, 184, 0.08);
}

.impl-info__box li:last-child {
	border-bottom: none;
}

.impl-info__box code {
	font-family: "SF Mono", Consolas, monospace;
	font-size: 13px;
	padding: 2px 8px;
	background: rgba(59, 130, 246, 0.1);
	border-radius: 4px;
	color: var(--accent-tx);
}

/* ============================================
   Footer
   ============================================ */
.page-footer {
	padding: 40px 0;
	text-align: center;
	border-top: 1px solid rgba(148, 163, 184, 0.1);
}

.page-footer p {
	font-size: 14px;
}

/* ============================================
   Animations - CSS Scroll Timeline
   ============================================ */
/*
 * animation-timeline: scroll(root)
 *
 * `scroll()` defaults to `scroll(nearest)`, which binds to the nearest ancestor
 * *scroll container* — and `overflow: hidden` makes an element a scroll container.
 * `.hero__cover` sits inside `.hero__frame` / `.hero__sticky`, both `overflow: hidden`,
 * so `scroll()` picked a container with no scrollable overflow: the timeline stayed
 * inactive and the cover never moved. `scroll(root)` binds to the document scroller,
 * which is what every animation here actually wants.
 */
@supports (animation-timeline: scroll()) {
	/* Progress Bar */
	.demo--native .progress-bar__fill {
		animation: fill-progress linear both;
		animation-timeline: scroll(root);
	}

	/* Hero Cover - moves up */
	.demo--native .hero__cover {
		animation: lift-cover linear both;
		animation-timeline: scroll(root);
		animation-range: 0% 40%;
	}

	.demo--native.demo--reverse .hero__cover {
		animation-direction: reverse;
		animation-range: 60% 100%;
	}

	/* Feature Cards */
	.demo--native .feature-card {
		animation: reveal-card linear both;
		animation-timeline: scroll(root);
	}

	.demo--native .feature-card:nth-child(1) { animation-range: 35% 50%; }
	.demo--native .feature-card:nth-child(2) { animation-range: 40% 55%; }
	.demo--native .feature-card:nth-child(3) { animation-range: 45% 60%; }

	.demo--native.demo--reverse .feature-card {
		animation-direction: reverse;
	}
	.demo--native.demo--reverse .feature-card:nth-child(1) { animation-range: 50% 65%; }
	.demo--native.demo--reverse .feature-card:nth-child(2) { animation-range: 45% 60%; }
	.demo--native.demo--reverse .feature-card:nth-child(3) { animation-range: 40% 55%; }

	/* Stat Cards */
	.demo--native .stat-card {
		animation: reveal-stat linear both;
		animation-timeline: scroll(root);
	}

	.demo--native .stat-card:nth-child(1) { animation-range: 55% 70%; }
	.demo--native .stat-card:nth-child(2) { animation-range: 60% 75%; }
	.demo--native .stat-card:nth-child(3) { animation-range: 65% 80%; }

	.demo--native.demo--reverse .stat-card {
		animation-direction: reverse;
	}
	.demo--native.demo--reverse .stat-card:nth-child(1) { animation-range: 30% 45%; }
	.demo--native.demo--reverse .stat-card:nth-child(2) { animation-range: 25% 40%; }
	.demo--native.demo--reverse .stat-card:nth-child(3) { animation-range: 20% 35%; }
}

@keyframes fill-progress {
	from { transform: scaleX(0); }
	to { transform: scaleX(1); }
}

@keyframes lift-cover {
	from { transform: translateY(0); }
	to { transform: translateY(-100%); }
}

@keyframes reveal-card {
	from {
		opacity: 0;
		transform: translateY(60px);
	}
	to {
		opacity: 1;
		transform: translateY(0);
	}
}

@keyframes reveal-stat {
	from {
		opacity: 0;
		transform: scale(0.9);
	}
	to {
		opacity: 1;
		transform: scale(1);
	}
}

/* ============================================
   IO & rAF - Transitions
   ============================================ */
.demo--io .feature-card,
.demo--io .stat-card,
.demo--raf .feature-card,
.demo--raf .stat-card {
	transition: opacity 0.6s ease, transform 0.6s ease;
}

.demo--io .hero__cover,
.demo--raf .hero__cover {
	transition: transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

/* ============================================
   Reduced Motion
   ============================================ */
@media (prefers-reduced-motion: reduce) {
	.hero__cover {
		transform: translateY(-100%) !important;
	}

	.feature-card,
	.stat-card {
		opacity: 1 !important;
		transform: none !important;
		transition: none !important;
	}

	.progress-bar__fill {
		transform: scaleX(1) !important;
	}
}

/* A11y Demo - stable states after activation */
.demo--a11y .feature-card.is-locked,
.demo--a11y .stat-card.is-locked {
	opacity: 1;
	transform: none;
	transition: none;
}