/**
 * UX Enhancements - Ernesto Theme
 * Back to Top, Sticky Header, Infinite Scroll, Reading Time
 *
 * @package Ernesto
 * @since 1.0.0
 */

/* ============================================
   1. BACK TO TOP BUTTON
   ============================================ */

.back-to-top {
	position: fixed;
	bottom: var(--space-xl);
	right: var(--space-xl);
	z-index: 999;
	width: 48px;
	height: 48px;
	padding: 0;
	border-radius: 50%;
	background-color: var(--color-primary);
	color: var(--text-on-brand);
	border: none;
	cursor: pointer;
	display: flex;
	align-items: center;
	justify-content: center;
	box-shadow: var(--shadow-md);
	transition: opacity 0.4s ease, visibility 0.4s ease,
	            background-color 0.2s ease, transform 0.2s ease;
	opacity: 0;
	visibility: hidden;
	transform: translateY(8px);
}

.back-to-top.visible {
	opacity: 0.72;
	visibility: visible;
	transform: translateY(0);
}

.back-to-top:hover,
.back-to-top:focus-visible {
	opacity: 1;
	background-color: var(--color-primary-hover);
	transform: scale(1.08);
}

.back-to-top:active {
	transform: scale(0.95);
	transition-duration: 0.1s;
}

.back-to-top:focus-visible {
	outline: 3px solid var(--text-on-brand);
	outline-offset: 4px;
}

.back-to-top svg {
	/* Override the global svg { height: auto; max-width: 100% } reset.
	   flex-shrink: 0 prevents the SVG collapsing to width: 0 inside the flex button. */
	width: 20px;
	min-width: 20px;
	height: 20px;
	flex-shrink: 0;
	pointer-events: none;
}

/* Mobile positioning */
@media (max-width: 768px) {
	.back-to-top {
		bottom: var(--space-lg);
		right: var(--space-lg);
		width: 44px;
		height: 44px;
	}

	.back-to-top svg {
		width: 20px;
		height: 20px;
	}
}

/* Hide on print */
@media print {
	.back-to-top {
		display: none;
	}
}

/* ============================================
   2. STICKY HEADER
   ============================================ */

.has-sticky-header .site-header {
	position: sticky;
	top: 0;
	z-index: 998;
	background-color: var(--bg-body);
	box-shadow: 0 2px 4px rgba(0, 0, 0, 0);
	transition: box-shadow var(--transition-fast),
	            background-color var(--transition-fast);
}

.has-sticky-header .site-header.scrolled {
	box-shadow: var(--shadow-md);
	background-color: var(--bg-surface);
}

/* Compact header when scrolled */
.has-sticky-header .site-header.scrolled .site-branding {
	padding: var(--space-sm) 0;
}

.has-sticky-header .site-header.scrolled .custom-logo {
	max-height: 40px;
	transition: max-height var(--transition-fast);
}

/* ============================================
   3. OFF-CANVAS MENU
   ============================================ */

.off-canvas-menu {
	position: fixed;
	top: 0;
	right: -100%;
	width: 320px;
	max-width: 85vw;
	height: 100vh;
	background-color: var(--bg-surface);
	box-shadow: var(--shadow-xl);
	z-index: 9999;
	overflow-y: auto;
	transition: right var(--transition-base);
	padding: var(--space-xl);
}

.off-canvas-menu.active {
	right: 0;
}

.off-canvas-overlay {
	position: fixed;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	background-color: rgba(0, 0, 0, 0.5);
	z-index: 9998;
	opacity: 0;
	visibility: hidden;
	transition: opacity var(--transition-base),
	            visibility var(--transition-base);
}

.off-canvas-overlay.active {
	opacity: 1;
	visibility: visible;
}

.off-canvas-close {
	position: absolute;
	top: var(--space-md);
	right: var(--space-md);
	width: 40px;
	height: 40px;
	border: none;
	background: transparent;
	cursor: pointer;
	display: flex;
	align-items: center;
	justify-content: center;
	border-radius: 50%;
	transition: background-color var(--transition-fast);
}

.off-canvas-close:hover {
	background-color: var(--bg-hover);
}

.off-canvas-close:focus-visible {
	outline: 2px solid var(--color-primary);
	outline-offset: 2px;
}

.off-canvas-menu .menu {
	list-style: none;
	padding: 0;
	margin: var(--space-2xl) 0 0 0;
}

.off-canvas-menu .menu-item {
	margin-bottom: var(--space-sm);
}

.off-canvas-menu .menu-item a {
	display: block;
	padding: var(--space-sm) var(--space-md);
	color: var(--text-main);
	text-decoration: none;
	border-radius: var(--border-radius-md);
	transition: background-color var(--transition-fast);
	font-weight: var(--font-weight-medium);
}

.off-canvas-menu .menu-item a:hover,
.off-canvas-menu .menu-item.current-menu-item a {
	background-color: var(--bg-hover);
	color: var(--color-primary);
}

/* ============================================
   4. INFINITE SCROLL
   ============================================ */

.infinite-scroll-container {
	position: relative;
}

.infinite-scroll-loading {
	display: none;
	text-align: center;
	padding: var(--space-xl) 0;
}

.infinite-scroll-loading.active {
	display: block;
}

.infinite-scroll-spinner {
	width: 40px;
	height: 40px;
	margin: 0 auto;
	border: 4px solid var(--border-color);
	border-top-color: var(--color-primary);
	border-radius: 50%;
	animation: spinner 0.8s linear infinite;
}

@keyframes spinner {
	to {
		transform: rotate(360deg);
	}
}

.infinite-scroll-message {
	text-align: center;
	padding: var(--space-lg) 0;
	color: var(--text-muted);
	font-size: var(--font-size-sm);
}

.infinite-scroll-error {
	text-align: center;
	padding: var(--space-lg);
	background-color: var(--color-error-bg);
	color: var(--color-error-text);
	border-radius: var(--border-radius-md);
	margin: var(--space-lg) 0;
}

/* Hide default pagination when infinite scroll is active */
.has-infinite-scroll .pagination,
.has-infinite-scroll .navigation {
	display: none;
}

/* ============================================
   5. READING TIME
   ============================================ */

.reading-time {
	display: inline-flex;
	align-items: center;
	gap: 0.25rem;
	font-size: var(--font-size-sm);
	color: var(--text-muted);
	font-weight: var(--font-weight-normal);
}

.reading-time svg {
	width: 16px;
	height: 16px;
	flex-shrink: 0;
}

.entry-meta .reading-time {
	margin-left: var(--space-sm);
}

/* ============================================
   6. SOCIAL SHARING BUTTONS
   ============================================ */

.social-sharing {
	display: flex;
	gap: var(--space-sm);
	align-items: center;
	margin: var(--space-xl) 0;
	padding: var(--space-lg) 0;
	border-top: 1px solid var(--border-color);
	border-bottom: 1px solid var(--border-color);
}

.social-sharing-label {
	font-weight: var(--font-weight-semibold);
	margin-right: var(--space-sm);
	color: var(--text-main);
}

.social-share-button {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	width: 40px;
	height: 40px;
	border-radius: 50%;
	text-decoration: none;
	transition: all var(--transition-fast);
	border: 2px solid transparent;
}

.social-share-button:hover {
	transform: translateY(-2px);
	box-shadow: var(--shadow-md);
}

.social-share-button:focus-visible {
	outline: 2px solid var(--color-primary);
	outline-offset: 4px;
}

.social-share-button svg {
	width: 20px;
	height: 20px;
}

/* Platform colors */
.share-twitter {
	background-color: #1DA1F2;
	color: #FFFFFF;
}

.share-twitter:hover {
	background-color: #1a91da;
	color: #FFFFFF;
}

.share-facebook {
	background-color: #1877F2;
	color: #FFFFFF;
}

.share-facebook:hover {
	background-color: #166fe5;
	color: #FFFFFF;
}

.share-linkedin {
	background-color: #0A66C2;
	color: #FFFFFF;
}

.share-linkedin:hover {
	background-color: #095196;
	color: #FFFFFF;
}

.share-email {
	background-color: var(--color-secondary);
	color: #FFFFFF;
}

.share-email:hover {
	background-color: var(--color-secondary-hover);
	color: #FFFFFF;
}

.share-copy {
	background-color: var(--bg-alt);
	color: var(--text-main);
	border-color: var(--border-color);
}

.share-copy:hover {
	background-color: var(--bg-hover);
	border-color: var(--color-primary);
}

.share-copy.copied {
	background-color: var(--color-success);
	color: #FFFFFF;
	border-color: var(--color-success);
}

/* Mobile responsive */
@media (max-width: 768px) {
	.social-sharing {
		flex-wrap: wrap;
	}

	.social-sharing-label {
		flex-basis: 100%;
		margin-bottom: var(--space-sm);
	}

	.social-share-button {
		width: 44px;
		height: 44px;
	}
}

/* ============================================
   7. LAZY LOAD VIDEOS (Placeholders)
   ============================================ */

.video-container {
	position: relative;
	padding-bottom: 56.25%; /* 16:9 */
	height: 0;
	overflow: hidden;
	background-color: #000000;
	border-radius: var(--border-radius-md);
	margin: var(--space-lg) 0;
}

.video-container iframe,
.video-container object,
.video-container embed {
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	border: 0;
}

.video-placeholder {
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	background-size: cover;
	background-position: center;
	cursor: pointer;
	display: flex;
	align-items: center;
	justify-content: center;
}

.video-placeholder::before {
	content: '';
	position: absolute;
	top: 0;
	left: 0;
	width: 100%;
	height: 100%;
	background-color: rgba(0, 0, 0, 0.3);
	transition: background-color var(--transition-fast);
}

.video-placeholder:hover::before {
	background-color: rgba(0, 0, 0, 0.5);
}

.video-play-button {
	position: relative;
	width: 80px;
	height: 80px;
	background-color: var(--color-primary);
	border-radius: 50%;
	display: flex;
	align-items: center;
	justify-content: center;
	transition: all var(--transition-fast);
	box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.video-placeholder:hover .video-play-button {
	transform: scale(1.1);
	background-color: var(--color-primary-hover);
}

.video-play-button::after {
	content: '';
	width: 0;
	height: 0;
	border-style: solid;
	border-width: 15px 0 15px 26px;
	border-color: transparent transparent transparent #FFFFFF;
	margin-left: 4px;
}

/* ============================================
   8. REDUCED MOTION
   ============================================ */

@media (prefers-reduced-motion: reduce) {
	.back-to-top,
	.social-share-button,
	.video-play-button {
		transition: none;
	}

	.off-canvas-menu,
	.off-canvas-overlay {
		transition: none;
	}

	.infinite-scroll-spinner {
		animation: none;
		border-top-color: var(--color-primary);
		border-right-color: var(--color-primary);
	}
}

.reduced-motion .back-to-top,
.reduced-motion .social-share-button,
.reduced-motion .video-play-button {
	transition: none;
}

/* ============================================
   9. PRINT
   ============================================ */

@media print {
	.back-to-top,
	.social-sharing,
	.off-canvas-menu,
	.off-canvas-overlay,
	.infinite-scroll-loading {
		display: none;
	}
}