/* ===== CSS变量 ===== */
:root {
    /* 亮色主题 */
    --bg-primary: #ffffff;
    --bg-secondary: #f5f7fa;
    --bg-tertiary: #e8ecf1;
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a6a;
    --text-muted: #8a8aa0;
    --border-color: #e0e4e8;
    --accent-color: #4a90d9;
    --accent-hover: #3a7bc8;
    --accent-light: #e8f2fc;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.15);
    --sidebar-width: 300px;
    --header-height: 50px;
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
}

[data-theme="dark"] {
    --bg-primary: #1a1a2e;
    --bg-secondary: #252542;
    --bg-tertiary: #2d2d4a;
    --text-primary: #e8e8f0;
    --text-secondary: #b8b8d0;
    --text-muted: #7878a0;
    --border-color: #3a3a5a;
    --accent-color: #6aa3e8;
    --accent-hover: #88b8f0;
    --accent-light: #2a3a5a;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.3);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.4);
}

/* ===== 基础样式 ===== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html, body {
    height: 100%;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Microsoft YaHei", sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-secondary);
}

/* ===== 布局容器 ===== */
.app-container {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* ===== 侧边栏 ===== */
.sidebar {
    width: var(--sidebar-width);
    min-width: var(--sidebar-width);
    height: 100vh;
    background: var(--bg-primary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-normal), width var(--transition-normal);
    z-index: 100;
}

.sidebar.collapsed {
    transform: translateX(calc(-1 * var(--sidebar-width)));
    width: 0;
    min-width: 0;
    overflow: hidden;
    visibility: hidden;
}

.sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px;
    border-bottom: 1px solid var(--border-color);
    background: var(--bg-primary);
}

.site-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.sidebar-toggle {
    background: none;
    border: none;
    padding: 6px;
    cursor: pointer;
    color: var(--text-secondary);
    border-radius: 6px;
    transition: all var(--transition-fast);
}

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

/* ===== 标签页 ===== */
.sidebar-tabs {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    padding: 0 8px;
    background: var(--bg-primary);
}

.sidebar-tab {
    flex: 1;
    padding: 10px 16px;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    position: relative;
    transition: all var(--transition-fast);
}

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

.sidebar-tab.active {
    color: var(--accent-color);
}

.sidebar-tab.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--accent-color);
}

.sidebar-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.tab-content {
    flex: 1;
    display: none;
    flex-direction: column;
    overflow: hidden;
}

.tab-content.active {
    display: flex;
}

/* ===== 快速搜索（目录标签）===== */
.quick-search-container {
    position: relative;
    padding: 12px 12px 8px 12px;
}

#quickSearchInput {
    width: 100%;
    padding: 8px 12px;
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    outline: none;
    transition: all var(--transition-fast);
}

#quickSearchInput:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px var(--accent-light);
}

#quickSearchInput::placeholder {
    color: var(--text-muted);
}

.quick-search-results {
    position: absolute;
    top: calc(100% - 8px);
    left: 12px;
    right: 12px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    max-height: 300px;
    overflow-y: auto;
    z-index: 1000;
    display: none;
    box-shadow: var(--shadow-lg);
}

.quick-search-results.active {
    display: block;
}

.search-result-item {
    padding: 10px 12px;
    cursor: pointer;
    border-bottom: 1px solid var(--border-color);
    transition: background var(--transition-fast);
}

.search-result-item:last-child {
    border-bottom: none;
}

.search-result-item:hover {
    background: var(--accent-light);
}

.search-result-title {
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 4px;
    font-size: 0.9rem;
}

.search-result-preview {
    font-size: 0.8rem;
    color: var(--text-muted);
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

.search-highlight {
    background: #fff3cd;
    padding: 0 2px;
    border-radius: 2px;
}

[data-theme="dark"] .search-highlight {
    background: #5a4a20;
}

/* ===== 完整搜索（搜索标签）===== */
.search-header {
    padding: 12px;
    border-bottom: 1px solid var(--border-color);
}

.search-input-group {
    display: flex;
    gap: 8px;
}

#searchInput {
    flex: 1;
    padding: 8px 12px;
    font-size: 0.9rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    outline: none;
    transition: all var(--transition-fast);
}

#searchInput:focus {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px var(--accent-light);
}

#searchInput::placeholder {
    color: var(--text-muted);
}

#searchButton {
    padding: 8px 16px;
    background: var(--accent-color);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: background var(--transition-fast);
}

#searchButton:hover {
    background: var(--accent-hover);
}

.search-results-panel {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
}

#searchStats {
    padding: 8px 12px;
    font-size: 0.85rem;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

.no-results {
    padding: 40px 20px;
    text-align: center;
    color: var(--text-muted);
}

.search-result-card {
    display: flex;
    gap: 12px;
    padding: 12px;
    margin-bottom: 8px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.search-result-card:hover {
    border-color: var(--accent-color);
    box-shadow: var(--shadow-sm);
}

.search-result-number {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    background: var(--accent-light);
    color: var(--accent-color);
    border-radius: 50%;
    font-size: 0.8rem;
    font-weight: 600;
    flex-shrink: 0;
}

.search-result-content {
    flex: 1;
    min-width: 0;
}

.search-result-card .search-result-title {
    font-size: 0.95rem;
    margin-bottom: 6px;
}

.search-result-card .search-result-preview {
    -webkit-line-clamp: 3;
    margin-bottom: 6px;
}

.search-result-path {
    font-size: 0.75rem;
    color: var(--text-muted);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* ===== 目录树（更紧凑）===== */
.toc-container {
    flex: 1;
    overflow-y: auto;
    padding: 6px 0;
}

.toc-tree {
    padding: 0 6px;
}

.toc-item {
    margin: 1px 0;
}

.toc-folder {
    display: flex;
    align-items: center;
    padding: 5px 10px;
    cursor: pointer;
    border-radius: 4px;
    color: var(--text-primary);
    font-weight: 500;
    transition: all var(--transition-fast);
    user-select: none;
}

.toc-folder:hover {
    background: var(--bg-tertiary);
}

.toc-folder-icon {
    width: 16px;
    height: 16px;
    margin-right: 6px;
    transition: transform var(--transition-fast);
    flex-shrink: 0;
}

.toc-folder.expanded .toc-folder-icon {
    transform: rotate(90deg);
}

.toc-folder-title {
    flex: 1;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 0.9rem;
}

/* 可点击的文件夹标题（有内容的目录） */
.toc-folder-link {
    flex: 1;
    padding: 0 !important;
    color: var(--text-primary) !important;
    font-size: 0.9rem;
}

.toc-folder-link:hover {
    color: var(--accent-color) !important;
    background: transparent !important;
}

/* 展开图标样式 - 让其更明显可点击 */
.toc-expand-toggle {
    cursor: pointer;
    opacity: 0.6;
}

.toc-expand-toggle:hover {
    opacity: 1;
}

.toc-children {
    display: none;
    padding-left: 14px;
}

.toc-children.expanded {
    display: block;
}

.toc-file {
    display: block;
    padding: 5px 10px 5px 32px;
    cursor: pointer;
    border-radius: 4px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-fast);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    font-size: 0.88rem;
}

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

.toc-file.active {
    background: var(--accent-light);
    color: var(--accent-color);
    font-weight: 500;
}

/* ===== 书签面板 ===== */
.bookmarks-panel {
    width: 280px;
    min-width: 280px;
    background: var(--bg-primary);
    border-left: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: all var(--transition-normal);
}

.bookmarks-panel.collapsed {
    width: 0;
    min-width: 0;
    transform: translateX(100%);
    border-left: none;
}

.bookmarks-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    border-bottom: 1px solid var(--border-color);
}

.bookmarks-title {
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
}

#bookmarksToggle {
    background: none;
    border: none;
    padding: 6px;
    cursor: pointer;
    color: var(--text-secondary);
    border-radius: 4px;
    transition: all var(--transition-fast);
}

#bookmarksToggle:hover {
    background: var(--bg-tertiary);
}

.bookmarks-actions {
    padding: 12px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    gap: 8px;
}

#addPageBookmark, #clearBookmarks {
    flex: 1;
    padding: 8px 12px;
    border: none;
    border-radius: 6px;
    font-size: 0.9rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    transition: background var(--transition-fast);
}

#addPageBookmark {
    background: var(--accent-color);
    color: white;
}

#addPageBookmark:hover {
    background: var(--accent-hover);
}

#clearBookmarks {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

#clearBookmarks:hover {
    background: #dc3545;
    color: white;
    border-color: #dc3545;
}

.bookmarks-list {
    flex: 1;
    overflow-y: auto;
    padding: 8px;
}

.bookmarks-empty {
    padding: 40px 20px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.bookmark-item {
    display: flex;
    gap: 10px;
    padding: 10px;
    margin-bottom: 6px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.bookmark-item:hover {
    border-color: var(--accent-color);
    box-shadow: var(--shadow-sm);
}

.bookmark-icon {
    font-size: 1.2rem;
    flex-shrink: 0;
}

.bookmark-content {
    flex: 1;
    min-width: 0;
}

.bookmark-title {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 4px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.bookmark-text {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-bottom: 4px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.bookmark-date {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.bookmark-delete {
    background: none;
    border: none;
    padding: 4px;
    cursor: pointer;
    color: var(--text-muted);
    border-radius: 4px;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.bookmark-delete:hover {
    background: var(--bg-tertiary);
    color: #e74c3c;
}

/* 浮动书签按钮 */
.floating-bookmark-button {
    position: fixed;
    padding: 6px 12px;
    background: var(--accent-color);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 0.85rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 4px;
    box-shadow: var(--shadow-md);
    z-index: 10000;
    transition: background var(--transition-fast);
}

.floating-bookmark-button:hover {
    background: var(--accent-hover);
}

/* ===== 主内容区 ===== */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    background: var(--bg-secondary);
}

.content-header {
    display: flex;
    align-items: center;
    padding: 8px 16px;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    min-height: var(--header-height);
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    padding: 6px;
    cursor: pointer;
    color: var(--text-secondary);
    border-radius: 6px;
    margin-right: 12px;
}

.menu-toggle:hover {
    background: var(--bg-tertiary);
}

.sidebar.collapsed + .main-content .menu-toggle {
    display: flex;
}

.breadcrumb {
    flex: 1;
    font-size: 0.9rem;
    color: var(--text-muted);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.breadcrumb-item {
    color: var(--text-secondary);
}

.breadcrumb-separator {
    margin: 0 8px;
    color: var(--text-muted);
}

.theme-toggle {
    background: none;
    border: none;
    padding: 8px;
    cursor: pointer;
    color: var(--text-secondary);
    border-radius: 6px;
    transition: all var(--transition-fast);
}

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

.bookmarks-open-toggle {
    background: none;
    border: none;
    padding: 8px;
    cursor: pointer;
    color: var(--text-secondary);
    border-radius: 6px;
    transition: all var(--transition-fast);
    margin-right: 4px;
}

.bookmarks-open-toggle:hover {
    background: var(--bg-tertiary);
    color: var(--accent-color);
}

.sun-icon {
    display: none;
}

.moon-icon {
    display: block;
}

[data-theme="dark"] .sun-icon {
    display: block;
}

[data-theme="dark"] .moon-icon {
    display: none;
}

/* ===== 内容区域 ===== */
.content-body {
    flex: 1;
    position: relative;
    display: none;
}

.content-body.active {
    display: block;
}

#contentFrame {
    width: 100%;
    height: 100%;
    border: none;
    background: var(--bg-primary);
}

.welcome-screen {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 40px;
}

.welcome-screen.hidden {
    display: none;
}

.welcome-content h2 {
    font-size: 1.75rem;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.welcome-content p {
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.welcome-content .tip {
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    /* 侧边栏移动端样式 */
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        height: 100%;
        z-index: 1000;
        box-shadow: var(--shadow-lg);
    }
    
    /* 移动端默认收起侧边栏 */
    .sidebar.collapsed {
        transform: translateX(-100%);
    }
    
    /* 移动端始终显示菜单按钮 */
    .menu-toggle {
        display: flex !important;
    }
    
    /* 移动端侧边栏内的收起按钮保留显示 */
    .sidebar-toggle {
        display: flex;
    }
    
    /* 书签面板移动端样式 */
    .bookmarks-panel {
        position: fixed;
        right: 0;
        top: 0;
        height: 100%;
        z-index: 999;
        box-shadow: var(--shadow-lg);
    }
    
    .bookmarks-panel.collapsed {
        transform: translateX(100%);
    }
    
    /* 移动端面包屑自适应 */
    .breadcrumb {
        flex: 1;
        min-width: 0;
    }
}

/* ===== 滚动条 ===== */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}