/**
 * Centi Theme — assets/css/tutorial.css
 *
 * Styles cho:
 *   - Level badges (dùng ở cả card và single)
 *   - Tutorial card (archive grid)
 *   - Tutorial archive: filter bar, grid
 *   - Tutorial single: layout, cover, meta, prereqs, GitHub link
 *   - TOC sidebar (sticky)
 *   - Reading progress bar
 */

/* -------------------------------------------------------------------------
 * Level badges
 * ---------------------------------------------------------------------- */

.level-badge {
	display: inline-flex;
	align-items: center;
	padding: 0.2em 0.65em;
	border-radius: var(--radius-sm);
	font-size: var(--font-size-xs);
	font-weight: var(--font-weight-semibold);
	text-transform: uppercase;
	letter-spacing: 0.04em;
	text-decoration: none;
	white-space: nowrap;
	line-height: 1.5;
}

.level-badge--basic {
	background-color: #dcfce7;
	color: #15803d;
}

.level-badge--mid {
	background-color: #fef3c7;
	color: #b45309;
}

.level-badge--advanced {
	background-color: #fee2e2;
	color: #b91c1c;
}

/* -------------------------------------------------------------------------
 * Tutorial card
 * ---------------------------------------------------------------------- */

.tutorial-card {
	display: flex;
	flex-direction: column;
	background-color: var(--color-bg);
	border: 1px solid var(--color-border);
	border-radius: var(--radius-lg);
	overflow: hidden;
	transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.tutorial-card:hover {
	box-shadow: var(--shadow-hover);
	transform: translateY(-2px);
}

/* Thumbnail */
.tutorial-card__thumbnail {
	display: block;
	position: relative;
	aspect-ratio: 16 / 9;
	overflow: hidden;
	flex-shrink: 0;
}

.tutorial-card__image {
	width: 100%;
	height: 100%;
	object-fit: cover;
	transition: transform var(--transition-slow, 400ms ease);
}

.tutorial-card:hover .tutorial-card__image {
	transform: scale(1.04);
}

/* Level badge overlay trên thumbnail */
.tutorial-card__thumbnail .level-badge {
	position: absolute;
	top: var(--space-3);
	left: var(--space-3);
	z-index: 1;
}

/* Body */
.tutorial-card__body {
	display: flex;
	flex-direction: column;
	flex: 1;
	padding: var(--space-5);
	gap: var(--space-3);
}

/* Topics */
.tutorial-card__topics {
	display: flex;
	flex-wrap: wrap;
	gap: var(--space-2);
}

.tutorial-card__topics .category-link {
	font-size: var(--font-size-xs);
	font-weight: var(--font-weight-semibold);
	text-transform: uppercase;
	letter-spacing: 0.05em;
	color: var(--color-tutorial);
	text-decoration: none;
}

.tutorial-card__topics .category-link:hover {
	text-decoration: underline;
}

/* Title */
.tutorial-card__title {
	font-size: var(--font-size-lg);
	font-weight: var(--font-weight-bold);
	line-height: var(--line-height-heading);
	margin: 0;
}

.tutorial-card__title a {
	color: var(--color-text);
	text-decoration: none;
}

.tutorial-card__title a:hover {
	color: var(--color-tutorial);
}

/* Excerpt */
.tutorial-card__excerpt {
	font-size: var(--font-size-sm);
	color: var(--color-text-muted);
	line-height: var(--line-height-body);
	margin: 0;
	flex: 1;
	display: -webkit-box;
	-webkit-line-clamp: 3;
	-webkit-box-orient: vertical;
	overflow: hidden;
}

/* Meta */
.tutorial-card__meta {
	display: flex;
	align-items: center;
	gap: var(--space-3);
	font-size: var(--font-size-xs);
	color: var(--color-text-muted);
	margin-top: auto;
	padding-top: var(--space-3);
	border-top: 1px solid var(--color-border);
}

.tutorial-card__duration,
.tutorial-card__reading-time {
	display: inline-flex;
	align-items: center;
	gap: var(--space-1);
}

/* -------------------------------------------------------------------------
 * Tutorial archive — filter bar
 * ---------------------------------------------------------------------- */

.tutorial-filter {
	margin: var(--space-6) 0;
}

.tutorial-filter__list {
	display: flex;
	flex-wrap: wrap;
	gap: var(--space-2);
	list-style: none;
	margin: 0;
	padding: 0;
}

.tutorial-filter__link {
	display: inline-block;
	padding: var(--space-2) var(--space-4);
	border: 1px solid var(--color-border);
	border-radius: var(--radius-xl);
	font-size: var(--font-size-sm);
	font-weight: var(--font-weight-medium);
	color: var(--color-text-muted);
	text-decoration: none;
	transition: border-color var(--transition-fast), color var(--transition-fast),
	            background-color var(--transition-fast);
}

.tutorial-filter__link:hover {
	border-color: var(--color-tutorial);
	color: var(--color-tutorial);
}

.tutorial-filter__link.is-active {
	background-color: var(--color-tutorial);
	border-color: var(--color-tutorial);
	color: #fff;
}

/* -------------------------------------------------------------------------
 * Tutorial archive — grid
 * ---------------------------------------------------------------------- */

.tutorials-grid {
	display: grid;
	grid-template-columns: 1fr;
	gap: var(--space-6);
}

@media (min-width: 640px) {
	.tutorials-grid {
		grid-template-columns: repeat(2, 1fr);
	}
}

@media (min-width: 1024px) {
	.tutorials-grid {
		grid-template-columns: repeat(3, 1fr);
	}
}

.tutorials-grid--sm {
	grid-template-columns: 1fr;
}

@media (min-width: 640px) {
	.tutorials-grid--sm {
		grid-template-columns: repeat(2, 1fr);
	}
}

@media (min-width: 1024px) {
	.tutorials-grid--sm {
		grid-template-columns: repeat(3, 1fr);
	}
}

/* -------------------------------------------------------------------------
 * Tutorial archive — page header
 * ---------------------------------------------------------------------- */

.page-header--tutorial {
	padding: var(--space-8) 0 0;
}

/* -------------------------------------------------------------------------
 * Tutorial single — layout (content + TOC sidebar)
 * ---------------------------------------------------------------------- */

.site-main--tutorial {
	padding: var(--space-8) 0 var(--space-16);
}

.tutorial-single-layout {
	display: grid;
	grid-template-columns: 1fr;
	gap: var(--space-8);
	align-items: start;
}

@media (min-width: 1024px) {
	.tutorial-single-layout {
		grid-template-columns: minmax(0, 1fr) 260px;
		gap: var(--space-12);
	}

	/* TOC sidebar là cột thứ 2, sticky */
	.tutorial-toc-sidebar {
		grid-column: 2;
		grid-row: 1;
	}

	/* Article chiếm cột 1, span qua các rows cần thiết */
	.tutorial-single {
		grid-column: 1;
	}

	.tutorial-related,
	.tutorial-single ~ .comments-area {
		grid-column: 1;
	}
}

/* -------------------------------------------------------------------------
 * Tutorial single — article
 * ---------------------------------------------------------------------- */

.tutorial-single__header {
	margin-bottom: var(--space-8);
}

.tutorial-single__badges {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: var(--space-2);
	margin-bottom: var(--space-4);
}

.tutorial-single__topics {
	display: inline-flex;
	flex-wrap: wrap;
	gap: var(--space-2);
}

.tutorial-single__topics .category-link {
	font-size: var(--font-size-xs);
	font-weight: var(--font-weight-semibold);
	text-transform: uppercase;
	letter-spacing: 0.05em;
	color: var(--color-tutorial);
	text-decoration: none;
}

.tutorial-single__topics .category-link:hover {
	text-decoration: underline;
}

.tutorial-single__title {
	font-size: var(--font-size-3xl);
	font-weight: var(--font-weight-bold);
	line-height: var(--line-height-heading);
	color: var(--color-text);
	margin: 0 0 var(--space-4);
}

@media (min-width: 768px) {
	.tutorial-single__title {
		font-size: var(--font-size-4xl);
	}
}

.tutorial-single__meta {
	display: flex;
	flex-wrap: wrap;
	align-items: center;
	gap: var(--space-2);
	font-size: var(--font-size-sm);
	color: var(--color-text-muted);
	margin-bottom: var(--space-4);
}

.tutorial-single__sep {
	color: var(--color-border);
}

.tutorial-single__duration,
.tutorial-single__reading-time {
	display: inline-flex;
	align-items: center;
	gap: var(--space-1);
}

/* Prerequisites */
.tutorial-single__prereqs {
	display: flex;
	flex-wrap: wrap;
	gap: var(--space-2);
	align-items: baseline;
	padding: var(--space-4) var(--space-5);
	background-color: var(--color-bg-secondary);
	border-left: 3px solid var(--color-tutorial);
	border-radius: 0 var(--radius-md) var(--radius-md) 0;
	font-size: var(--font-size-sm);
	margin-bottom: var(--space-4);
}

/* GitHub link */
.tutorial-single__github-link {
	display: inline-flex;
	align-items: center;
	gap: var(--space-2);
	padding: var(--space-2) var(--space-4);
	border: 1px solid var(--color-border);
	border-radius: var(--radius-md);
	font-size: var(--font-size-sm);
	font-weight: var(--font-weight-medium);
	color: var(--color-text);
	text-decoration: none;
	transition: border-color var(--transition-fast), color var(--transition-fast);
}

.tutorial-single__github-link:hover {
	border-color: var(--color-text);
	color: var(--color-text);
}

/* Cover image */
.tutorial-single__cover {
	margin-bottom: var(--space-8);
	border-radius: var(--radius-lg);
	overflow: hidden;
	aspect-ratio: 3 / 1;
}

.tutorial-single__cover-image {
	width: 100%;
	height: 100%;
	object-fit: cover;
}

/* Content */
.tutorial-single__content {
	font-size: var(--font-size-base);
	line-height: var(--line-height-body);
	color: var(--color-text);
	max-width: var(--content-max);
}

.tutorial-single__content h2,
.tutorial-single__content h3,
.tutorial-single__content h4 {
	scroll-margin-top: calc(var(--header-height) + var(--space-6));
}

/* Footer */
.tutorial-single__footer {
	margin-top: var(--space-10);
	padding-top: var(--space-6);
	border-top: 1px solid var(--color-border);
}

/* -------------------------------------------------------------------------
 * Tutorial related posts
 * ---------------------------------------------------------------------- */

.tutorial-related {
	margin-top: var(--space-12);
}

.tutorial-related__heading {
	font-size: var(--font-size-2xl);
	font-weight: var(--font-weight-bold);
	margin-bottom: var(--space-6);
}

/* -------------------------------------------------------------------------
 * TOC sidebar
 * ---------------------------------------------------------------------- */

.tutorial-toc-sidebar {
	display: none;
}

@media (min-width: 1024px) {
	.tutorial-toc-sidebar {
		display: block;
	}

	.tutorial-toc-sidebar__inner {
		position: sticky;
		top: calc(var(--header-height) + var(--space-6));
		max-height: calc(100vh - var(--header-height) - var(--space-12));
		overflow-y: auto;
		padding: var(--space-5);
		background-color: var(--color-bg-secondary);
		border: 1px solid var(--color-border);
		border-radius: var(--radius-lg);

		/* Custom scrollbar */
		scrollbar-width: thin;
		scrollbar-color: var(--color-border) transparent;
	}
}

.tutorial-toc-sidebar__heading {
	font-size: var(--font-size-xs);
	font-weight: var(--font-weight-semibold);
	text-transform: uppercase;
	letter-spacing: 0.08em;
	color: var(--color-text-muted);
	margin: 0 0 var(--space-3);
}

.toc-list {
	list-style: none;
	margin: 0;
	padding: 0;
}

.toc-list__item {
	margin-bottom: var(--space-1);
}

.toc-list__link {
	display: block;
	padding: var(--space-1) var(--space-2);
	font-size: var(--font-size-sm);
	color: var(--color-text-muted);
	text-decoration: none;
	border-radius: var(--radius-sm);
	line-height: 1.5;
	transition: color var(--transition-fast), background-color var(--transition-fast);
}

.toc-list__link:hover {
	color: var(--color-text);
	background-color: var(--color-border);
}

.toc-list__link.is-active {
	color: var(--color-tutorial);
	font-weight: var(--font-weight-medium);
	background-color: #dcfce7;
}

/* Sub-list (h3) */
.toc-list--sub {
	margin-top: var(--space-1);
	padding-left: var(--space-4);
}

.toc-list__item--sub .toc-list__link {
	font-size: var(--font-size-xs);
}

/* -------------------------------------------------------------------------
 * Reading progress bar
 * ---------------------------------------------------------------------- */

.progress-bar {
	position: fixed;
	top: 0;
	left: 0;
	width: 0;
	height: 3px;
	background: linear-gradient(
		90deg,
		var(--color-tutorial) 0%,
		var(--color-primary) 100%
	);
	z-index: 9999;
	transition: width 100ms linear;
	pointer-events: none;
}

/* -------------------------------------------------------------------------
 * Meta icon (SVG inline)
 * ---------------------------------------------------------------------- */

.meta-icon {
	flex-shrink: 0;
	vertical-align: middle;
}