/* ===== 大纲面板 (TOC) 样式 ===== */

/* --- 桌面端大纲面板 --- */
.toc-panel {
    width: var(--toc-width, 220px);
    min-width: var(--toc-width, 220px);
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-light);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: width 0.25s ease, min-width 0.25s ease, opacity 0.2s ease;
    position: relative;
    flex-shrink: 0;
}

.toc-panel.resizing {
    transition: none;
}

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

.toc-panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.75rem 0.75rem 0.5rem;
    flex-shrink: 0;
}

.toc-panel-title {
    font-size: 0.8125rem;
    font-weight: 600;
    color: var(--text-secondary);
    letter-spacing: 0.02em;
    white-space: nowrap;
    overflow: hidden;
}

/* 外观全部来自 .kb-header-icon-btn（css/nav-controls.css），与其它标题栏按钮同规格 */

.toc-panel-body {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 0 0.5rem 0.75rem;
    -webkit-overflow-scrolling: touch;
}

.toc-panel-body::-webkit-scrollbar {
    width: 4px;
}

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

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

.toc-panel-body::-webkit-scrollbar-thumb:hover {
    background: var(--text-tertiary);
}

/* --- 桌面端贴边折叠按钮（与 sidebar-toggle-btn 完全对称，贴在大纲面板右边缘朝右凸出） --- */
.toc-edge-toggle {
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    z-index: 10;
    width: 16px;
    height: 44px;
    /* 显式压掉 mobile.css 给 button 兜的 min-width: 32px（min-width 不看特异度），理由见 .ai-sidebar-toggle */
    min-width: 16px;
    min-height: 44px;
    padding: 0;
    border: none;
    border-radius: 0 6px 6px 0;
    background: var(--bg-secondary, #f3f4f6);
    color: rgb(100, 116, 139);
    cursor: pointer;
    font-size: 0.8rem;
    display: flex;
    align-items: center;
    justify-content: center;
    /* box-shadow: 2px 0 8px rgba(0, 0, 0, 0.1); */
    transition: left 0.25s ease, background 0.2s, color 0.2s;
}

.toc-edge-toggle:hover {
    background: var(--bg-tertiary, rgb(229, 231, 235));
    color: rgb(30, 41, 59);
}

.toc-edge-toggle i {
    transition: transform 0.25s ease;
    line-height: 1;
}

.toc-panel:not(.collapsed) ~ .toc-edge-toggle {
    left: var(--toc-width, 220px);
}

.toc-panel:not(.collapsed) ~ .toc-edge-toggle i {
    transform: rotate(180deg);
}

[data-theme="dark"] .toc-edge-toggle {
    background: rgb(38, 50, 66);
    color: rgb(148, 163, 184);
}

[data-theme="dark"] .toc-edge-toggle:hover {
    background: rgb(55, 65, 81);
    color: rgb(226, 232, 240);
}

/* --- 拖拽调宽手柄 --- */
.toc-resize-handle {
    width: 1px;
    flex-shrink: 0;
    cursor: col-resize;
    background: transparent;
    transition: background 0.2s ease;
    position: relative;
    z-index: 11;
    display: none;
}

.toc-panel:not(.collapsed) ~ .toc-resize-handle {
    display: block;
}

.toc-resize-handle:hover {
    background: rgba(0, 0, 0, 0.08);
}

.toc-resize-handle.active {
    background: transparent;
}

.toc-panel.resizing ~ .toc-edge-toggle {
    transition: none;
}

/* --- TOC 列表 --- */
.toc-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.toc-item {
    margin: 0;
    padding: 0;
}

.toc-link {
    display: block;
    padding: 0.375rem 0.5rem;
    font-size: 0.8125rem;
    line-height: 1.4;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.15s ease;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    border-left: 2px solid transparent;
    margin-bottom: 1px;
}

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

.toc-link.active {
    color: var(--primary-color);
    background: rgba(59, 130, 246, 0.08);
    border-left-color: var(--primary-color);
    font-weight: 500;
}

/* TOC 层级缩进 */
.toc-item[data-level="1"] .toc-link {
    padding-left: 0.5rem;
    font-weight: 500;
    font-size: 0.8125rem;
}

.toc-item[data-level="2"] .toc-link {
    padding-left: 1.25rem;
    font-size: 0.8125rem;
}

.toc-item[data-level="3"] .toc-link {
    padding-left: 2rem;
    font-size: 0.75rem;
}

/* --- 标题折叠指示器（实心三角，内联紧跟标题末尾） --- */
.knowledge-content h1.toc-collapsible,
.knowledge-content h2.toc-collapsible,
.knowledge-content h3.toc-collapsible {
    cursor: pointer;
}

.knowledge-content h1.toc-collapsible::after,
.knowledge-content h2.toc-collapsible::after,
.knowledge-content h3.toc-collapsible::after {
    content: '';
    display: inline-block;
    width: 0;
    height: 0;
    margin-left: 0.25em;
    vertical-align: 0.14em;
    border-left: 0.28em solid transparent;
    border-right: 0.28em solid transparent;
    border-top: 0.34em solid #374151;
    opacity: 0;
    transition: opacity 0.15s ease, transform 0.2s ease;
    transform-origin: center 35%;
}

.knowledge-content h1.toc-collapsible:hover::after,
.knowledge-content h2.toc-collapsible:hover::after,
.knowledge-content h3.toc-collapsible:hover::after,
.knowledge-content h1.toc-collapsible.section-collapsed-heading::after,
.knowledge-content h2.toc-collapsible.section-collapsed-heading::after,
.knowledge-content h3.toc-collapsible.section-collapsed-heading::after {
    opacity: 0.85;
}

.knowledge-content h1.toc-collapsible.section-collapsed-heading::after,
.knowledge-content h2.toc-collapsible.section-collapsed-heading::after,
.knowledge-content h3.toc-collapsible.section-collapsed-heading::after {
    transform: rotate(-90deg);
}

/* 折叠区域 */
.heading-section-content {
    display: flow-root;
    overflow: hidden;
    transition: max-height 0.3s ease, opacity 0.2s ease;
    opacity: 1;
}

.heading-section-content.collapsed {
    max-height: 0 !important;
    opacity: 0;
    margin: 0;
    padding: 0;
}

/* 折叠状态的标题样式 */
.knowledge-content h1.section-collapsed-heading,
.knowledge-content h2.section-collapsed-heading,
.knowledge-content h3.section-collapsed-heading {
    margin-bottom: 0.125rem;
}

/* --- 移动端大纲右侧滑入浮层 --- */
.toc-slide-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--kb-scrim-bg);
    backdrop-filter: blur(var(--kb-scrim-blur));
    -webkit-backdrop-filter: blur(var(--kb-scrim-blur));
    z-index: 1100;
    display: none;
    opacity: 0;
    transition: opacity 0.25s ease;
}

.toc-slide-overlay.show {
    display: block;
    opacity: 1;
}

.toc-slide-panel {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: 75vw;
    max-width: 320px;
    background: var(--bg-primary);
    z-index: 1101;
    display: flex;
    flex-direction: column;
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: -4px 0 24px rgba(0, 0, 0, 0.15);
}

.toc-slide-panel.show {
    transform: translateX(0);
}

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

.toc-slide-panel-title {
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--text-primary);
}

.toc-slide-panel-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

/* 同上：外观来自 .kb-header-icon-btn */

.toc-slide-panel-body {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 0.5rem 0.75rem 1rem;
    -webkit-overflow-scrolling: touch;
}

.toc-slide-panel-body .toc-list {
    padding: 0;
}

.toc-slide-panel-body .toc-link {
    padding: 0.25rem 0.75rem;
    font-size: 0.875rem;
    border-radius: 8px;
    min-height: 40px;
    display: flex;
    align-items: center;
    white-space: normal;
    overflow: visible;
    text-overflow: unset;
    line-height: 1.5;
}

.toc-slide-panel-body .toc-item[data-level="1"] .toc-link {
    padding-left: 0.75rem;
    font-weight: 500;
}

.toc-slide-panel-body .toc-item[data-level="2"] .toc-link {
    padding-left: 1.75rem;
}

.toc-slide-panel-body .toc-item[data-level="3"] .toc-link {
    padding-left: 2.75rem;
    font-size: 0.8125rem;
}

/* --- 大纲为空时 --- */
.toc-empty {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    min-height: 200px;
    padding: 2rem 1rem;
    color: var(--text-tertiary);
    font-size: 0.8125rem;
    text-align: center;
    gap: 0rem;
}

.toc-empty i {
    font-size: 2.5rem;
    opacity: 0.45;
}

/* --- 深色主题适配 --- */
[data-theme="dark"] .toc-panel {
    background: var(--bg-secondary);
    border-right-color: var(--border-color);
}

[data-theme="dark"] .toc-link.active {
    background: rgba(96, 165, 250, 0.1);
    color: var(--primary-color);
    border-left-color: var(--primary-color);
}

[data-theme="dark"] .toc-link:hover {
    background: var(--bg-tertiary);
}

[data-theme="dark"] .toc-slide-panel {
    background: var(--bg-primary);
    box-shadow: -4px 0 24px rgba(0, 0, 0, 0.4);
}

/* 暗色主题下三角使用浅色 */
[data-theme="dark"] .knowledge-content h1.toc-collapsible::after,
[data-theme="dark"] .knowledge-content h2.toc-collapsible::after,
[data-theme="dark"] .knowledge-content h3.toc-collapsible::after {
    border-top-color: #d1d5db;
}

/* --- 桌面端隐藏移动端相关元素 --- */
@media (min-width: 1024px) {
    .toc-slide-overlay,
    .toc-slide-panel {
        display: none !important;
    }
}

/* --- 移动端隐藏桌面端大纲面板 --- */
@media (max-width: 1023px) {
    .toc-panel,
    .toc-edge-toggle,
    .toc-resize-handle {
        display: none !important;
    }

    /* 移动端标题折叠三角常驻显示 */
    .knowledge-content h1.toc-collapsible::after,
    .knowledge-content h2.toc-collapsible::after,
    .knowledge-content h3.toc-collapsible::after {
        opacity: 0.5;
    }
}