/* --- Reading Mode Toggle --- */
.reading-mode-toggle {
	display: inline-flex;
	align-items: center;
	gap: var(--spacing-sm);
	padding: var(--spacing-sm) var(--spacing-md);
	font-size: 0.875rem;
	font-weight: 500;
	border: 1px solid var(--color-border);
	border-radius: var(--radius-md);
	background: var(--color-bg);
	color: var(--color-text-secondary);
	cursor: pointer;
	transition: color var(--transition), border-color var(--transition);
}

.reading-mode-toggle:hover {
	color: var(--color-primary);
	border-color: var(--color-primary);
}

.reading-mode-toggle[aria-pressed="true"] {
	color: var(--color-primary);
	border-color: var(--color-primary);
	background: rgba(9, 105, 218, 0.05);
}

/* --- Reading Mode Layout --- */
.reading-mode .site-header,
.reading-mode .site-footer,
.reading-mode .archive-header,
.reading-mode .breadcrumbs,
.reading-mode .single-article__meta-details,
.reading-mode .single-article__meta,
.reading-mode .single-article__thumbnail,
.reading-mode .single-article__actions,
.reading-mode .archive-filters,
.reading-mode .category-badge,
.reading-mode .site-header__actions .search-form,
.reading-mode .site-header__actions .favorites-toggle,
.reading-mode .site-header__actions .favorites-dropdown,
.reading-mode .book-hero,
.reading-mode .book-recommendations {
	display: none;
}

.reading-mode .main-content {
	padding-top: var(--spacing-2xl);
}

.reading-mode .single-article {
	max-width: var(--max-width);
	display: grid;
	grid-template-columns: 240px 1fr;
	gap: var(--spacing-3xl);
}

.reading-mode .table-of-contents {
	grid-column: 1;
}

.reading-mode .single-article__main {
	grid-column: 2;
	min-width: 0;
}

.reading-mode .single-article__header,
.reading-mode .book-metadata {
	grid-column: 1 / -1;
}

.reading-mode .single-article__content {
	max-width: var(--content-width);
}

/* --- Table of Contents --- */
.table-of-contents {
	position: sticky;
	top: calc(var(--header-height) + var(--spacing-xl));
	align-self: start;
	font-size: 0.875rem;
	max-height: calc(100vh - var(--header-height) - var(--spacing-3xl));
	overflow-y: auto;
	display: none;
}

.reading-mode .table-of-contents {
	display: block;
}

.table-of-contents__title {
	font-size: 0.75rem;
	font-weight: 600;
	text-transform: uppercase;
	letter-spacing: 0.5px;
	color: var(--color-text-secondary);
	margin-bottom: var(--spacing-md);
	padding-bottom: var(--spacing-sm);
	border-bottom: 1px solid var(--color-border);
}

.table-of-contents__list {
	list-style: none;
	padding: 0;
	margin: 0;
}

.table-of-contents__item {
	margin-bottom: 2px;
}

.table-of-contents__item--sub {
	padding-left: var(--spacing-md);
}

.table-of-contents__link {
	display: block;
	padding: 4px var(--spacing-sm);
	color: var(--color-text-secondary);
	border-radius: var(--radius-sm);
	transition: color var(--transition), background var(--transition);
	border-left: 2px solid transparent;
	text-decoration: none;
	font-size: 0.8125rem;
	line-height: 1.5;
}

.table-of-contents__link:hover {
	color: var(--color-primary);
	background: var(--color-bg-alt);
	text-decoration: none;
}

.table-of-contents__link.is-active {
	color: var(--color-primary);
	border-left-color: var(--color-primary);
	font-weight: 600;
}

/* --- Responsive Reading Mode --- */
@media (max-width: 768px) {
	.reading-mode .single-article {
		grid-template-columns: 1fr;
		gap: var(--spacing-lg);
	}

	.reading-mode .table-of-contents,
	.reading-mode .single-article__main {
		grid-column: 1;
	}

	.reading-mode .table-of-contents {
		position: relative;
		top: 0;
		max-height: none;
		margin-bottom: var(--spacing-xl);
	}
}

body.dark-mode .table-of-contents__link.is-active {
	color: var(--color-primary);
}