/* ========================================
   TOC Sidebar
   ======================================== */
.toc-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-overlay);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
    z-index: 150;
}

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

.toc-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 280px;
    height: 100vh;
    background: var(--color-bg);
    border-right: 1px solid var(--color-border);
    transform: translateX(-100%);
    transition: transform var(--transition-normal);
    z-index: 151;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.toc-sidebar.active {
    transform: translateX(0);
}

.toc-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid var(--color-border);
    flex-shrink: 0;
}

.toc-title {
    font-family: var(--ui-serif);
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-primary);
}

.toc-close {
    width: 32px;
    height: 32px;
    border: none;
    background: transparent;
    color: var(--color-text-secondary);
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.toc-close:hover {
    background: var(--color-bg-secondary);
    color: var(--color-primary);
}

.toc-close svg {
    width: 18px;
    height: 18px;
}

.toc-nav {
    flex: 1;
    overflow-y: auto;
    padding: var(--space-md);
}

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

.toc-item {
    margin-bottom: var(--space-xs);
}

.toc-link {
    display: block;
    padding: var(--space-xs) var(--space-sm);
    color: var(--color-text);
    font-size: 0.875rem;
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    border-left: 2px solid transparent;
}

.toc-link:hover {
    background: var(--color-bg-secondary);
    color: var(--color-primary);
}

.toc-link.active {
    background: var(--color-bg-secondary);
    border-left-color: var(--color-accent);
    color: var(--color-primary);
    font-weight: 500;
}

.toc-item[data-level="1"] .toc-link {
    font-weight: 500;
    padding-left: var(--space-sm);
}

.toc-item[data-level="2"] .toc-link {
    padding-left: calc(var(--space-sm) + 12px);
    font-size: 0.8125rem;
}

.toc-item[data-level="3"] .toc-link {
    padding-left: calc(var(--space-sm) + 24px);
    font-size: 0.75rem;
    color: var(--color-text-secondary);
}

.toc-item[data-level="3"] .toc-link:hover {
    color: var(--color-primary);
}

.toc-empty {
    text-align: center;
    color: var(--color-text-muted);
    font-size: 0.875rem;
    padding: var(--space-xl);
}

/* ========================================
   Floating TOC - Left Side
   ======================================== */

.floating-toc {
    position: fixed;
    left: var(--space-lg);
    top: 50%;
    transform: translateY(-50%);
    z-index: 90;
    max-height: 70vh;
    overflow-y: auto;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-normal);
    background: transparent;
    /* Hide scrollbar for Chrome, Safari, Opera */
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.floating-toc::-webkit-scrollbar {
    display: none;
}

.floating-toc.visible {
    opacity: 1;
    pointer-events: auto;
}

/* Hide header in floating TOC - now shown directly via title bar button */
.floating-toc-header {
    display: none;
}

.floating-toc-nav {
    display: block;
    background: transparent;
    max-height: 70vh;
    overflow-y: auto;
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.floating-toc-nav::-webkit-scrollbar {
    display: none;
}

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

.floating-toc-nav .toc-item {
    margin-bottom: var(--space-xs);
}

.floating-toc-nav .toc-link {
    display: block;
    padding: var(--space-xs) var(--space-sm);
    color: var(--color-text);
    font-size: 0.875rem;
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
    white-space: normal;
    word-wrap: break-word;
    max-width: 220px;
    line-height: 1.5;
}

.floating-toc-nav .toc-link:hover {
    color: var(--color-accent);
}

.floating-toc-nav .toc-link.active {
    background: linear-gradient(90deg, var(--color-accent), #F39C12);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 600;
}

.floating-toc-nav .toc-item[data-level="1"] .toc-link {
    font-weight: 500;
    color: var(--color-text-secondary);
}

.floating-toc-nav .toc-item[data-level="2"] .toc-link {
    padding-left: calc(var(--space-sm) + 12px);
    font-size: 0.8125rem;
    opacity: 0.9;
}

.floating-toc-nav .toc-item[data-level="3"] .toc-link {
    padding-left: calc(var(--space-sm) + 24px);
    font-size: 0.75rem;
    opacity: 0.8;
}