/**
 * toc.css - Table of Contents sidebar styles
 */

/* TOC Panel Container */
.toc-panel {
    display: flex;
    flex-direction: column;
    width: var(--toc-width);
    min-width: var(--toc-min-width);
    max-width: var(--toc-max-width);
    height: 100%;
    background: var(--bg-primary);
    border-right: 1px solid var(--border-color);
    position: relative;
    transition: width 0.2s ease, min-width 0.2s ease, opacity 0.2s ease;
    overflow: hidden;
    flex-shrink: 0;
}

/* Collapsed state */
.toc-panel.collapsed {
    width: 0;
    min-width: 0;
    border-right: none;
    opacity: 0;
    pointer-events: none;
}

/* TOC Header */
.toc-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 12px;
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0;
    background: var(--bg-secondary);
}

.toc-title {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 11px;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin: 0;
}

.toc-title svg {
    width: 14px;
    height: 14px;
}

.toc-actions {
    display: flex;
    gap: 2px;
}

.toc-btn {
    padding: 4px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    border-radius: 4px;
    transition: all 0.15s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.toc-btn:hover {
    background: var(--bg-tertiary);
    color: var(--text-primary);
}

.toc-btn svg {
    width: 14px;
    height: 14px;
}

/* TOC Search */
.toc-search {
    position: relative;
    padding: 8px 12px;
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0;
}

.toc-search-icon {
    position: absolute;
    left: 20px;
    top: 50%;
    transform: translateY(-50%);
    width: 12px;
    height: 12px;
    color: var(--text-secondary);
    pointer-events: none;
}

.toc-search-input {
    width: 100%;
    padding: 5px 24px 5px 28px;
    font-size: 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    outline: none;
    transition: border-color 0.15s, background 0.15s;
}

.toc-search-input:focus {
    border-color: var(--accent-color);
    background: var(--bg-primary);
}

.toc-search-input::placeholder {
    color: var(--text-secondary);
    opacity: 0.7;
}

.toc-search-clear {
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    padding: 2px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    cursor: pointer;
    opacity: 0;
    transition: opacity 0.15s;
    display: flex;
    align-items: center;
}

.toc-search-input:not(:placeholder-shown) ~ .toc-search-clear {
    opacity: 1;
}

.toc-search-clear:hover {
    color: var(--text-primary);
}

.toc-search-clear svg {
    width: 10px;
    height: 10px;
}

/* TOC Navigation */
.toc-nav {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
}

.toc-list {
    list-style: none;
    margin: 0;
    padding: 4px 0;
}

.toc-item {
    position: relative;
}

.toc-item.hidden {
    display: none;
}

.toc-link {
    display: flex;
    align-items: center;
    padding: 5px 12px;
    font-size: 12px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all 0.15s;
    cursor: pointer;
    border-left: 2px solid transparent;
    line-height: 1.4;
}

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

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

/* Heading level indentation */
.toc-level-1 .toc-link { padding-left: 12px; font-weight: 500; color: var(--text-primary); }
.toc-level-2 .toc-link { padding-left: 24px; }
.toc-level-3 .toc-link { padding-left: 36px; font-size: 11px; }
.toc-level-4 .toc-link { padding-left: 48px; font-size: 11px; opacity: 0.9; }
.toc-level-5 .toc-link { padding-left: 60px; font-size: 11px; opacity: 0.8; }
.toc-level-6 .toc-link { padding-left: 72px; font-size: 11px; opacity: 0.7; }

.toc-text {
    flex: 1;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Highlight matching search text */
.toc-text mark {
    background: var(--accent-color);
    color: white;
    padding: 0 2px;
    border-radius: 2px;
}

/* Empty state */
.toc-empty {
    display: none;
    padding: 20px 12px;
    text-align: center;
    color: var(--text-secondary);
}

.toc-empty p {
    margin: 0 0 4px;
    font-size: 12px;
}

.toc-empty span {
    font-size: 11px;
    opacity: 0.7;
}

.toc-nav:has(.toc-list:empty) .toc-empty {
    display: block;
}

/* No results state */
.toc-no-results {
    display: none;
    padding: 16px 12px;
    text-align: center;
    font-size: 11px;
    color: var(--text-secondary);
}

/* TOC Resizer */
.toc-resizer {
    position: absolute;
    top: 0;
    right: 0;
    width: 4px;
    height: 100%;
    background: transparent;
    cursor: col-resize;
    transition: background 0.15s;
    z-index: 10;
}

.toc-resizer:hover,
.toc-resizer.dragging {
    background: var(--accent-color);
}

/* Toggle button (shown when collapsed) */
.toc-toggle-btn {
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    padding: 12px 6px;
    border: 1px solid var(--border-color);
    border-left: none;
    border-radius: 0 6px 6px 0;
    background: var(--bg-primary);
    color: var(--text-secondary);
    cursor: pointer;
    box-shadow: 2px 0 8px rgba(0,0,0,0.1);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s, background 0.15s;
    z-index: 100;
    display: flex;
    align-items: center;
}

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

.toc-toggle-btn svg {
    width: 14px;
    height: 14px;
}

/* Show toggle when TOC is collapsed */
.toc-panel.collapsed ~ .toc-toggle-btn {
    opacity: 1;
    pointer-events: auto;
}

/* TOC visible in all modes */

/* Scrollbar styling for TOC */
.toc-nav::-webkit-scrollbar {
    width: 4px;
}

.toc-nav::-webkit-scrollbar-track {
    background: transparent;
}

.toc-nav::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 2px;
}

.toc-nav::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

/* Heading highlight when scrolled to */
.toc-highlight {
    animation: tocHighlight 1.5s ease-out;
}

@keyframes tocHighlight {
    0% { background: rgba(74, 144, 217, 0.2); }
    100% { background: transparent; }
}

/* Responsive */
@media (max-width: 900px) {
    .toc-panel {
        --toc-width: 180px;
        --toc-min-width: 140px;
    }
}

@media (max-width: 768px) {
    .toc-panel,
    .toc-toggle-btn {
        display: none !important;
    }
}