* { margin: 0; padding: 0; box-sizing: border-box; }
        /* 强制亮色 — 永远白底，禁止变暗 */
        :root {
            --primary: #7C6FF7; --primary-dark: #5E4ED8; --primary-light: #A89BFF; --primary-dim: rgba(124,111,247,0.10);
            --accent: #7C6FF7; --accent2: #FB7185; --accent3: #F59E0B;
            --bg-dark: #F0F2F5; --bg-main: #F8F9FA; --bg-body: #F0F2F5; --bg-card: #FFFFFF; --bg-card-hover: #F5F3FF; --card: var(--bg-card);
            --text-primary: #1E1E2E; --text-secondary: #4B5563; --text-muted: #6B7280;
            --border: #E5E7EB; --border-light: #F3F4F6; --border-glow: rgba(124,111,247,0.20);
            --success: #10B981; --warning: #F59E0B; --danger: #EF4444; --info: #60A5FA; --new-glow: #FF4757;
            --glass-bg: rgba(255,255,255,0.85); --glass-border: rgba(0,0,0,0.05);
            --shadow-sm: 0 1px 3px rgba(0,0,0,0.06); --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
            --shadow-lg: 0 8px 24px rgba(0,0,0,0.10); --shadow-glow: 0 0 20px rgba(124,111,247,0.10);
            --radius-sm: 8px; --radius: 12px; --radius-lg: 16px; --radius-xl: 20px;
        }
        [data-theme="dark"] {
            --primary: #2DD4BF; --primary-dark: #14B8A6; --primary-light: #5EEAD4; --primary-dim: rgba(45,212,191,0.15);
            --accent: #2DD4BF; --accent2: #FB7185; --accent3: #FACC15;
            --bg-dark: #101820; --bg-main: #141E28; --bg-body: #101820; --bg-card: #1A2430; --bg-card-hover: #212D3A; --card: var(--bg-card);
            --text-primary: #E2E8F0; --text-secondary: #8899AA; --text-muted: #6B7D8E;
            --border: #263340; --border-light: #2E3D4C; --border-glow: rgba(45,212,191,0.18);
            --glass-bg: rgba(26,36,48,0.85); --glass-border: rgba(255,255,255,0.05);
            --shadow-sm: 0 2px 8px rgba(0,0,0,0.3); --shadow-md: 0 4px 20px rgba(0,0,0,0.4);
            --shadow-lg: 0 8px 40px rgba(0,0,0,0.5); --shadow-glow: 0 0 24px rgba(45,212,191,0.10);
        }
        body { font-family: "PingFang SC","Microsoft YaHei",-apple-system,sans-serif; background: var(--bg-body); color: var(--text-primary); min-height: 100vh; -webkit-user-select:none; user-select:none; cursor:default; }
        /* 自定义滚动条 */
        ::-webkit-scrollbar { width: 6px; height: 6px; }
        ::-webkit-scrollbar-track { background: transparent; }
        ::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }
        ::-webkit-scrollbar-thumb:hover { background: var(--border-light); }
        input, textarea, [contenteditable] { -webkit-user-select:text; user-select:text; cursor:text; caret-color:auto; }
        a:not(.btn):not([onclick]) { -webkit-user-select:text; user-select:text; cursor:pointer !important; pointer-events:auto !important; }
        .kb-article-body:not(.editing) { caret-color:transparent; cursor:default; }
        .kb-article-body.editing { caret-color: var(--accent) !important; cursor: text !important; }
        select { -webkit-user-select:none; user-select:none; cursor:default; -webkit-appearance:none; appearance:none; }
        select:focus { outline:none; }
        select option { background: var(--bg-card); color: var(--text-primary); }
        ::placeholder { color: var(--text-muted); opacity: 1; }
        :-ms-input-placeholder { color: var(--text-muted); }
        ::-ms-input-placeholder { color: var(--text-muted); }

        /* === 导航栏（简洁顶栏） === */
        .navbar { background: var(--glass-bg); backdrop-filter: blur(24px) saturate(180%); -webkit-backdrop-filter: blur(24px) saturate(180%); padding: 6px 24px; display: flex; justify-content: space-between; align-items: center; position: sticky; top: 0; z-index: 100; border-bottom: 1px solid var(--border); min-height: 48px; box-shadow: var(--shadow-sm); }
        .navbar .logo { display: flex; align-items: center; gap: 10px; }
        .navbar .logo a { display: flex; align-items: center; text-decoration: none; }
        .navbar .logo img { height: 40px; vertical-align: middle; }
        
        .navbar .actions { display: flex; gap: 16px; align-items: center; }
        
        /* 签到按钮样式 */
        .checkin-btn {
            display: flex;
            align-items: center;
            gap: 6px;
            padding: 6px 14px;
            height: 32px;
            background: linear-gradient(135deg, #FF8A5B, #FF6B45);
            border: none;
            border-radius: 16px;
            color: white;
            font-weight: 600;
            font-size: 0.8em;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 2px 8px rgba(255, 106, 69, 0.25);
            white-space: nowrap;
        }
        
        .checkin-btn:hover {
            transform: translateY(-1px);
            box-shadow: 0 4px 12px rgba(255, 106, 69, 0.35);
        }
        
        .checkin-btn:active {
            transform: translateY(0);
        }
        
        .checkin-icon {
            font-size: 1em;
            line-height: 1;
        }
        
        .checkin-text {
            line-height: 1;
        }
        
        /* 积分显示样式 */
        .points-display {
            display: flex;
            align-items: center;
            gap: 6px;
            padding: 6px 14px;
            height: 32px;
            background: linear-gradient(135deg, #FFF4E0, #FFE8B8);
            border: 1.5px solid #FFD700;
            border-radius: 16px;
            color: #8B4513;
            font-weight: 700;
            font-size: 0.85em;
            box-shadow: 0 2px 8px rgba(255, 215, 0, 0.2);
            white-space: nowrap;
        }
        
        .points-icon {
            font-size: 1.1em;
            line-height: 1;
        }
        
        .points-value {
            font-size: 1em;
            letter-spacing: 0.3px;
            line-height: 1;
        }
        
        /* 响应式调整 */
        @media (max-width: 768px) {
            .navbar .actions { gap: 10px; }
            
            .checkin-btn {
                padding: 6px 12px;
                font-size: 0.75em;
                gap: 4px;
            }
            
            .checkin-text {
                display: none;
            }
            
            .points-display {
                padding: 6px 12px;
                font-size: 0.8em;
                gap: 4px;
            }
        }
        .nav-left { display: flex; align-items: center; gap: 30px; }
        .nav-menu { display: flex; gap: 30px; align-items: center; }
        .nav-menu-item { padding: 6px 14px; cursor: pointer; font-size: 0.95em; font-weight: 500; color: var(--text-secondary); background: transparent; border: none; transition: all 0.25s; text-decoration: none; user-select: none; letter-spacing: 0.5px; border-radius: 6px; }
        .nav-menu-item:hover { color: var(--text-primary); background: rgba(124,111,247,0.06); }
        .nav-menu-item.active { color: var(--accent); font-weight: 700; background: rgba(0,212,204,0.06); }

        /* === 主布局：左侧边栏 + 内容区 === */
        .main-layout { display: flex; min-height: calc(100vh - 48px); }
        .main-sidebar { width: 220px; min-width: 220px; background: var(--bg-main); border-right: 1px solid var(--border); padding: 20px 16px; overflow-y: auto; position: sticky; top: 48px; height: calc(100vh - 48px); display: flex; flex-direction: column; gap: 8px; }
        .main-layout.hw-detail-mode .main-sidebar { width: 200px; min-width: 200px; padding: 16px 10px; }
        .main-sidebar .sb-section { margin-bottom: 8px; }
        .main-sidebar .sb-section-title { font-size: 0.7em; color: var(--text-muted); text-transform: uppercase; letter-spacing: 1px; margin-bottom: 6px; padding: 0 4px; font-weight: 700; }
        .main-sidebar .sb-nav-item { display: flex; align-items: center; gap: 10px; width: 100%; padding: 9px 12px; border-radius: 6px; cursor: pointer; font-size: 0.88em; font-weight: 500; color: var(--text-secondary); background: transparent; border: none; transition: all 0.2s; text-align: left; text-decoration: none; }
        .main-sidebar .sb-nav-item:hover { background: rgba(45,212,191,0.08); color: var(--text-primary); }
        .main-sidebar .sb-nav-item.active { background: rgba(45,212,191,0.12); color: var(--accent); font-weight: 700; }
        .main-sidebar .sb-nav-item .sb-badge { margin-left: auto; background: rgba(45,212,191,0.15); color: var(--accent); font-size: 0.72em; padding: 2px 8px; border-radius: 12px; font-weight: 600; }
        .main-sidebar .sb-nav-item .sb-badge.red { background: rgba(239,68,68,0.15); color: #ef4444; }
        .main-sidebar .sb-nav-item .sb-badge.green { background: rgba(16,185,129,0.15); color: #10b981; }
        .main-sidebar .sb-nav-item .sb-badge.yellow { background: rgba(232,183,48,0.15); color: #e8b730; }
        .main-sidebar select { width: 100%; background: rgba(255,255,255,0.06); color: var(--text-primary); border: 1px solid rgba(255,255,255,0.12); border-radius: 6px; padding: 8px 10px; font-size: 0.82em; cursor: pointer; outline: none; margin-bottom: 6px; }
        .main-sidebar .sb-submit-btn { width: 100%; margin-top: 8px; padding: 10px; border-radius: 6px; background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: #fff; border: none; font-size: 0.9em; font-weight: 600; cursor: pointer; transition: all 0.2s; }
        .main-sidebar .sb-submit-btn:hover { box-shadow: 0 4px 16px rgba(45,212,191,0.3); transform: translateY(-1px); }

        /* 侧边栏知识库树 — 用圆点表示，参考作业辅导样式 */
        #sbKbTreeSection .kb-tree { padding: 0; max-height: 55vh; overflow-y: auto; }
        #sbKbTreeSection .kb-tree-toggle,
        #sbKbTreeSection .kb-tree-leaf { 
            color: var(--text-secondary); 
            padding: 5px 8px; margin: 1px 0;
            border-radius: 6px;
            display: flex; align-items: center; gap: 7px;
            font-size: 0.82em; cursor: pointer;
            transition: all 0.15s;
        }
        #sbKbTreeSection .kb-tree-toggle:hover,
        #sbKbTreeSection .kb-tree-leaf:hover { background: rgba(45,212,191,0.08); color: var(--text-primary); }
        #sbKbTreeSection .kb-tree-toggle.active,
        #sbKbTreeSection .kb-tree-leaf.active { color: var(--accent); background: rgba(45,212,191,0.12); font-weight: 600; }
        #sbKbTreeSection .kb-tree-toggle.active .kb-node-dot,
        #sbKbTreeSection .kb-tree-leaf.active .kb-node-dot { background: var(--accent) !important; }
        #sbKbTreeSection .kb-node-dot { width: 7px; height: 7px; border-radius: 50%; flex-shrink: 0; margin: 0 2px; }
        #sbKbTreeSection .kb-tree-arrow { display: none; }
        #sbKbTreeSection .kb-node-title { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
        #sbKbTreeSection .kb-node-count { color: var(--text-muted); font-size: 0.7em; margin-left: auto; }
        #sbKbTreeSection .kb-tree-children { padding-left: 0; margin-left: 14px; }
        #sbKbTreeSection .kb-tree-children.collapsed { display: none; }
        #sbKbTreeSection .kb-three-dot-btn,
        #sbKbTreeSection .kb-hover-add { display: none !important; }
        #sbKbTreeSection .kb-edit-toggle { display: block; border: 1px solid var(--border); color: var(--text-muted); border-radius: 6px; background: transparent; cursor: pointer; padding: 4px 10px; font-size: 0.72em; transition: all 0.15s; }
        #sbKbTreeSection .kb-edit-toggle:hover { border-color: var(--accent); color: var(--accent); }
        #sbKbTreeSection .kb-edit-btn { border: 1px solid var(--border); background: transparent; color: var(--text-muted); border-radius: 4px; cursor: pointer; font-size: 0.78em; padding: 2px 6px; transition: all 0.15s; }
        #sbKbTreeSection .kb-edit-btn:hover { border-color: var(--accent); color: var(--accent); background: var(--primary-dim); }
        #sbKbTreeSection .kb-edit-btn.danger:hover { border-color: #e17055; color: #e17055; background: rgba(232,120,74,0.08); }
        #sbKbTreeSection .kb-sidebar-edit-bar-inline { display: flex; align-items: center; gap: 6px; }
        .main-content-area { 
            flex: 1; 
            min-width: 0; 
            overflow: hidden; 
            position: relative;
            height: calc(100vh - 48px);
        }
        
        /* 确保每个主视图容器独立占据整个内容区 */
        #gridView,
        #knowledgeView,
        #helpView,
        #liveView,
        #detailView {
            position: absolute !important;
            top: 0 !important;
            left: 0 !important;
            right: 0 !important;
            bottom: 0 !important;
            overflow-y: auto !important;
            overflow-x: hidden !important;
            display: none !important;
        }
        
        #gridView.show,
        #knowledgeView.show,
        #helpView.show,
        #liveView.show,
        #detailView.show {
            display: block !important;
        }

        /* 移动端：侧边栏隐藏 */
        @media (max-width: 768px) {
            .main-sidebar { display: none; }
            .main-layout { flex-direction: column; }
            .navbar { padding: 6px 12px; }
            .main-content-area { width: 100%; padding: 0 8px; overflow-x: hidden; }
            /* 卡片网格单列 */
            .thumbnail-grid { grid-template-columns: 1fr !important; gap: 12px; padding: 4px 4px 36px; }
            .thumb-card { max-width: 100%; }
            /* 导航栏适配 */
            .nav-menu { gap: 12px; overflow-x: auto; -webkit-overflow-scrolling: touch; }
            .nav-menu-item { font-size: 0.82em; padding: 5px 10px; white-space: nowrap; flex-shrink: 0; }
            .navbar .logo img { height: 32px; }
            .nav-left { gap: 12px; }
            /* 模态弹窗适配 */
            .modal { max-width: 95vw !important; margin: 10px; }
            /* 知识库布局 */
            .kb-layout { flex-direction: column; }
            .kb-sidebar { width: 100%; height: auto; max-height: 40vh; position: relative; top: 0; }
            .kb-content { height: auto; }
            /* 管理后台适配 */
            #userManagePage .kb-sidebar { width: 100%; max-height: 200px; overflow-y: auto; flex-shrink: 0; }
            #userManagePage .kb-content { flex-direction: column; }
        }

        /* === 左侧树形班级筛选 === */
        .sb-tree { display: flex; flex-direction: column; gap: 1px; }
        .sb-tree-node { cursor: pointer; user-select: none; }
        .sb-tree-node .node-row { display: flex; align-items: center; gap: 6px; padding: 7px 6px 7px 2px; border-radius: 6px; transition: all 0.15s; font-size: 0.82em; color: var(--text-secondary); }
        .sb-tree-node .node-row:hover { background: rgba(45,212,191,0.06); color: var(--text-primary); }
        .sb-tree-node .node-row.active { background: rgba(45,212,191,0.12); color: var(--accent); font-weight: 700; }
        .sb-tree-node .node-arrow { font-size: 0.65em; transition: transform 0.25s; width: 16px; text-align: center; color: var(--text-muted); flex-shrink: 0; }
        .sb-tree-node.expanded > .node-row .node-arrow { transform: rotate(90deg); }
        .sb-tree-node .node-dot { width: 7px; height: 7px; border-radius: 50%; flex-shrink: 0; margin: 0 2px; }
        .sb-tree-node .node-label { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
        .sb-tree-node .node-count { font-size: 0.7em; color: var(--text-muted); flex-shrink: 0; }
        .sb-tree-children { display: none; padding-left: 18px; }
        .sb-tree-node.expanded > .sb-tree-children { display: flex; flex-direction: column; gap: 1px; }
        .sb-tree-node.root-node > .node-row { font-size: 0.84em; font-weight: 600; }
        .sb-tree-node.root-node .node-arrow { display: inline-block; }
        .sb-tree-node.leaf-node .node-arrow { display: none; }

        /* === 知识库 === */
        .kb-layout { display: flex; min-height: calc(100vh - 56px); }
        .kb-sidebar { width: 280px; flex-shrink: 0; background: var(--bg-card); border-right: 1px solid var(--border); overflow-y: auto; position: sticky; top: 96px; height: calc(100vh - 96px); }
        /* 管理后台的 kb-sidebar 不受 sticky/top 影响，自适应父容器高度 */
        #userManagePage .kb-sidebar { position: relative; top: 0; height: 100%; width: 240px; }
        .kb-sidebar-header { padding: 12px 16px; font-weight: 700; font-size: 1.05em; border-bottom: 1px solid var(--border); color: var(--accent); display: flex; align-items: center; justify-content: space-between; }
        .kb-content { flex: 1; padding: 0; overflow-y: auto; height: calc(100vh - 56px); }

        /* 树形目录 */
        .kb-tree { padding: 8px 0; }
        .kb-tree-node { user-select: none; }
        .kb-tree-toggle { display: flex; align-items: center; position: relative; gap: 6px; padding: 9px 16px; cursor: pointer; color: var(--text-secondary); font-size: 0.9em; font-weight: 600; transition: all 0.2s; border-left: 3px solid transparent; }
        .kb-tree-toggle:hover { background: rgba(108,92,231,0.06); color: var(--text-primary); border-left-color: var(--primary); }
        .kb-tree-toggle.active { color: var(--accent); background: rgba(108,92,231,0.08); border-left-color: var(--accent); }
        .kb-tree-arrow { font-size: 0.65em; transition: transform 0.25s; width: 16px; text-align: center; color: var(--text-muted); }
        .kb-tree-arrow.expanded { transform: rotate(90deg); }
        .kb-tree-icon { font-size: 1.1em; }
        .kb-tree-children { padding-left: 18px; overflow: hidden; }
        .kb-tree-children.collapsed { display: none; }
        .kb-tree-leaf { display: flex; align-items: center; position: relative; gap: 8px; padding: 8px 16px 8px 22px; cursor: pointer; color: var(--text-secondary); font-size: 0.88em; transition: all 0.2s; border-left: 3px solid transparent; }
        .kb-tree-leaf:hover { color: var(--accent); background: rgba(108,92,231,0.05); border-left-color: rgba(108,92,231,0.3); }
        .kb-tree-leaf.active { color: var(--accent); background: rgba(108,92,231,0.1); border-left-color: var(--accent); font-weight: 600; }
        .kb-tree-leaf-icon { font-size: 1em; opacity: 0.7; }

        /* 内容区 */
        .kb-placeholder { display: flex; flex-direction: column; align-items: center; justify-content: center; min-height: 60vh; padding: 30px 40px; }
        .kb-placeholder-icon { font-size: 4em; margin-bottom: 16px; opacity: 0.5; }
        .kb-placeholder-title { font-size: 1.4em; margin-bottom: 8px; background: linear-gradient(135deg, var(--accent), var(--primary)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
        .kb-placeholder-desc { color: var(--text-secondary); font-size: 0.95em; }

        /* 文章页 */
        .kb-article-header { margin-bottom: 24px; padding-bottom: 16px; border-bottom: 1px solid var(--border); }
        .kb-article-title { font-size: 1.6em; font-weight: 700; margin-bottom: 8px; }
        .kb-article-meta { display: flex; gap: 16px; align-items: center; justify-content: space-between; }
        .kb-article-path { color: var(--text-muted); font-size: 0.85em; }
        .kb-copy-link-btn { background: transparent; border: 1px solid var(--border); color: var(--text-muted); font-size: 0.7em; padding: 3px 8px; border-radius: 6px; cursor: pointer; display: inline-flex; align-items: center; gap: 4px; transition: all 0.15s; }
        .kb-copy-link-btn:hover { background: var(--accent); color: #fff; border-color: var(--accent); }
        .kb-editor-toolbar { display: none; align-items: center; gap: 2px; padding: 6px 12px; background: var(--bg-dark); border-bottom: 1px solid var(--border); border-radius: 8px 8px 0 0; flex-wrap: wrap; position: sticky; top: 0; z-index: 10; }
        .kb-editor-toolbar.show { display: flex; }
        .kb-editor-toolbar .sep { width: 1px; height: 20px; background: var(--border); margin: 0 4px; }
        .kb-editor-btn { background: transparent; border: none; color: var(--text-secondary); cursor: pointer; padding: 4px 8px; border-radius: 5px; font-size: 14px; line-height: 1.2; min-width: 28px; text-align: center; transition: all 0.2s ease; font-weight: 500; user-select: none; }
        .kb-editor-btn:hover { background: rgba(124,111,247,0.1); color: var(--primary); transform: translateY(-1px); }
        .kb-editor-btn:active { transform: translateY(0) scale(0.97); }
        .kb-editor-btn.active { background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: #fff; }
        .kb-editor-btn svg { width: 16px; height: 16px; vertical-align: middle; }
        .kb-save-indicator { margin-left: auto; font-size: 0.75em; color: var(--text-muted); display: flex; align-items: center; gap: 4px; }
        .kb-save-indicator.saving { color: var(--accent); }
        .kb-save-indicator.saved { color: var(--success); }
        .kb-color-picker { position: absolute; top: 36px; left: 0; background: var(--card); border: 1px solid var(--border); border-radius: 6px; padding: 8px; box-shadow: 0 4px 12px rgba(0,0,0,0.3); z-index: 1000; display: none; grid-template-columns: repeat(8, 20px); gap: 4px; }
        .kb-color-picker.show { display: grid; }
        .kb-color-swatch { width: 20px; height: 20px; border-radius: 4px; cursor: pointer; border: 2px solid transparent; transition: transform 0.1s; }
        .kb-color-swatch:hover { transform: scale(1.15); border-color: var(--text-primary); }
        .kb-article-body.editing { border: 1px solid var(--border); border-top: none; border-radius: 0 0 8px 8px; padding: 16px; min-height: 400px; line-height: 1.8; color: var(--text-primary); font-size: 0.95em; outline: none; background: var(--bg-dark); }
        .kb-article-body.editing .kb-link-copy-btn { display: none; }
        .kb-article-body { min-height: 400px; line-height: 1.8; color: var(--text-primary); font-size: 0.95em; outline: none; background: transparent; }
        .kb-article-body h1 { font-size: 1.6em; font-weight: 700; margin: 24px 0 12px; color: var(--text-primary); border-bottom: 1px solid var(--border); padding-bottom: 6px; }
        .kb-article-body h2 { font-size: 1.35em; font-weight: 700; margin: 20px 0 10px; color: var(--text-primary); }
        .kb-article-body h3 { font-size: 1.15em; font-weight: 600; margin: 16px 0 8px; color: var(--text-primary); }
        /* 确保标题中的链接包装器不换行 */
        .kb-article-body h1 .kb-link-wrapper,
        .kb-article-body h2 .kb-link-wrapper,
        .kb-article-body h3 .kb-link-wrapper,
        .kb-article-body h4 .kb-link-wrapper,
        .kb-article-body h5 .kb-link-wrapper,
        .kb-article-body h6 .kb-link-wrapper { display: inline-flex !important; white-space: nowrap !important; vertical-align: middle; gap: 8px; }
        .kb-article-body:focus { background: var(--bg-dark); border-radius: 6px; }
        .kb-article-body:empty::before { content: '在此输入内容...'; color: var(--text-muted); }
        .kb-article-body a { color: var(--accent); text-decoration: none; cursor: pointer; border-bottom: 1.5px solid rgba(108,92,231,0.45); border-radius: 2px; padding: 1px 3px; transition: all 0.15s; word-break: break-all; pointer-events: auto !important; user-select: text !important; }
        .kb-article-body a:hover { background: rgba(108,92,231,0.12); border-bottom-color: #6C5CE7; box-shadow: 0 0 6px rgba(108,92,231,0.25); transform: translateY(-1px); }
        .kb-link-icon { font-size: 0.85em; opacity: 0.85; flex-shrink: 0; pointer-events: none; }
        .kb-link-text { text-decoration: underline; text-underline-offset: 2px; }
        .kb-article-body a:visited { color: #6C5CE7; border-bottom-color: rgba(167,139,250,0.35); }
        /* 图片自适应 */
        .kb-article-body img { max-width: 100%; height: auto; display: block; border-radius: 6px; }
        .kb-article-body ul, .kb-article-body ol { padding-left: 24px; margin: 8px 0; }
        .kb-article-body li { margin: 4px 0; }
        .kb-article-body ul ul, .kb-article-body ol ol, .kb-article-body ul ol, .kb-article-body ol ul { margin: 4px 0; padding-left: 28px; }
        /* 表格样式 */
        .kb-article-body table { border-collapse: collapse; width: 100%; margin: 12px 0; border: 1px solid var(--border); }
        .kb-article-body table td, .kb-article-body table th { border: 1px solid var(--border); padding: 8px 10px; min-width: 50px; font-size: 0.92em; color: var(--text-secondary); vertical-align: top; }
        .kb-article-body table th { background: rgba(108,92,231,0.08); font-weight: 600; color: var(--text-primary); }
        .kb-article-body table tr:hover td { background: rgba(108,92,231,0.03); }
        /* 表格右键菜单 */
        .kb-table-menu { position: fixed; background: var(--card); border: 1px solid var(--border); border-radius: 6px; box-shadow: 0 4px 16px rgba(0,0,0,0.35); padding: 4px 0; z-index: 9999; min-width: 160px; }
        .kb-table-menu-item { padding: 8px 16px; font-size: 0.85em; color: var(--text-secondary); cursor: pointer; display: flex; align-items: center; gap: 8px; }
        .kb-table-menu-item:hover { background: rgba(108,92,231,0.08); color: var(--text-primary); }
        .kb-table-menu-sep { height: 1px; background: var(--border); margin: 4px 0; }
        /* 表格插入网格选择器 */
        .kb-table-grid-popup { position: absolute; background: var(--card); border: 1px solid var(--border); border-radius: 6px; box-shadow: 0 4px 16px rgba(0,0,0,0.35); padding: 10px; z-index: 9999; }
        .kb-table-grid-popup-label { font-size: 0.7em; color: var(--text-muted); margin-bottom: 6px; text-align: center; }
        .kb-table-grid { display: grid; grid-template-columns: repeat(6, 20px); grid-template-rows: repeat(5, 20px); gap: 2px; }
        .kb-table-grid-cell { border: 1px solid var(--border); border-radius: 2px; cursor: pointer; }
        .kb-table-grid-cell.highlight { background: rgba(108,92,231,0.2); border-color: var(--accent); }

        /* 链接插入弹窗 */
        .kb-link-modal-backdrop { position: fixed; inset: 0; background: rgba(0,0,0,0.55); display: flex; align-items: center; justify-content: center; z-index: 9999; opacity: 0; pointer-events: none; transition: opacity 0.2s; }
        .kb-link-modal-backdrop.show { opacity: 1; pointer-events: auto; }
        .kb-link-modal { background: var(--card); border: 1px solid var(--border); border-radius: 10px; padding: 20px 24px; width: 360px; max-width: 90vw; box-shadow: var(--shadow-lg); }
        .kb-link-modal h3 { margin: 0 0 14px 0; font-size: 1.05em; color: var(--text-primary); }
        .kb-link-modal-input { width: 100%; padding: 8px 12px; border: 1px solid var(--border); border-radius: 6px; background: var(--bg); color: var(--text-primary); font-size: 0.9em; box-sizing: border-box; margin-bottom: 14px; }
        .kb-link-modal-input:focus { outline: none; border-color: var(--accent); }
        .kb-link-modal-actions { display: flex; justify-content: flex-end; gap: 10px; }
        .kb-link-btn-cancel { padding: 6px 14px; border: 1px solid var(--border); background: transparent; color: var(--text-secondary); border-radius: 6px; cursor: pointer; font-size: 0.85em; }
        .kb-link-btn-cancel:hover { background: var(--hover); }
        .kb-link-btn-ok { padding: 6px 14px; border: none; background: var(--accent); color: #fff; border-radius: 6px; cursor: pointer; font-size: 0.85em; }
        .kb-link-btn-ok:hover { background: #6C5CE7; }

/* 历史版本弹窗 */
.kb-history-backdrop { position: fixed; inset: 0; background: rgba(0,0,0,0.55); display: flex; align-items: center; justify-content: center; z-index: 9999; opacity: 0; pointer-events: none; transition: opacity 0.2s; }
.kb-history-backdrop.show { opacity: 1; pointer-events: auto; }
.kb-history-modal { background: var(--bg-card); border: 1px solid var(--border); border-radius: 12px; padding: 20px 24px; width: 520px; max-width: 90vw; max-height: 75vh; box-shadow: var(--shadow-lg); display: flex; flex-direction: column; }
.kb-history-modal h3 { margin: 0 0 4px 0; font-size: 1.05em; color: var(--text-primary); }
.kb-history-modal .kb-history-sub { font-size: 0.7em; color: var(--text-muted); margin-bottom: 14px; }
.kb-history-list { flex: 1; overflow-y: auto; margin-bottom: 10px; }
.kb-history-item { display: flex; align-items: center; gap: 8px; padding: 8px 12px; border-bottom: 1px solid var(--border); cursor: pointer; transition: background 0.15s; font-size: 0.88em; color: var(--text-secondary); }
.kb-history-item:hover { background: rgba(108,92,231,0.06); }
.kb-history-item .kb-history-status { width: 6px; height: 6px; border-radius: 50%; background: var(--accent); flex-shrink: 0; }
.kb-history-item .kb-history-status.current { background: var(--success); }
.kb-history-item .kb-history-time { flex: 1; font-size: 0.85em; }
.kb-history-item .kb-history-node { font-size: 0.7em; color: var(--text-muted); }
.kb-history-item .kb-history-actions { display: flex; gap: 6px; flex-shrink: 0; }
.kb-history-btn { padding: 3px 10px; border-radius: 4px; border: 1px solid var(--border); background: transparent; color: var(--text-secondary); font-size: 0.75em; cursor: pointer; transition: all 0.15s; }
.kb-history-btn:hover { border-color: var(--accent); color: var(--accent); }
.kb-history-btn.restore:hover { background: var(--accent); color: #fff; border-color: var(--accent); }
.kb-history-empty { text-align: center; padding: 30px; color: var(--text-muted); font-size: 0.9em; }
.kb-history-current-tag { font-size: 0.7em; color: var(--success); background: rgba(0,184,148,0.1); padding: 1px 6px; border-radius: 3px; }
.kb-history-modal-footer { display: flex; justify-content: flex-end; gap: 8px; }

        /* 班级权限弹窗 */
        .kb-class-modal-backdrop { position: fixed; inset: 0; background: rgba(0,0,0,0.55); display: flex; align-items: center; justify-content: center; z-index: 9999; opacity: 0; pointer-events: none; transition: opacity 0.2s; }
        .kb-class-modal-backdrop.show { opacity: 1; pointer-events: auto; }
        .kb-class-modal { background: var(--card); border: 1px solid var(--border); border-radius: 10px; padding: 20px 24px; width: 400px; max-width: 90vw; box-shadow: var(--shadow-lg); max-height: 80vh; overflow-y: auto; }
        .kb-class-modal h3 { margin: 0 0 14px 0; font-size: 1.05em; color: var(--text-primary); }
        .kb-class-modal-desc { font-size: 0.85em; color: var(--text-muted); margin-bottom: 14px; }
        .kb-class-modal-group { margin-bottom: 14px; }
        .kb-class-modal-group-title { font-weight: 600; font-size: 0.9em; color: var(--text-primary); margin-bottom: 6px; padding-bottom: 4px; border-bottom: 1px solid var(--border); }
        .kb-class-modal-item { display: flex; align-items: center; gap: 8px; padding: 4px 0; font-size: 0.88em; color: var(--text-secondary); cursor: pointer; }
        .kb-class-modal-item:hover { color: var(--text-primary); }
        .kb-class-modal-item input { cursor: pointer; }
        .kb-class-modal-actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 16px; }

        /* ========= 文章大纲 ========== */
        .kb-article { display: flex; gap: 0; position: relative; }
        .kb-toc-panel {
            width: 200px; flex-shrink: 0;
            padding: 16px 0 0 0;
            border-right: 1px solid var(--border);
            overflow-y: auto;
            position: sticky; top: 0;
            align-self: flex-start;
            max-height: calc(100vh - 56px);
            transition: width 0.25s, padding 0.25s;
            flex-direction: column;
        }
        .kb-toc-panel.collapsed {
            width: 28px; padding: 0;
            border-right: 1px solid var(--border);
            overflow: hidden;
            cursor: pointer;
        }
        .kb-toc-panel.collapsed .kb-toc-title,
        .kb-toc-panel.collapsed .kb-toc-list { display: none; }
        .kb-toc-toggle-btn {
            display: flex; align-items: center; justify-content: center;
            width: 100%; height: 28px; margin-top: auto;
            border: none; background: transparent; color: var(--text-muted);
            cursor: pointer; font-size: 0.85em; transition: all 0.2s;
            border-top: 1px solid transparent;
        }
        .kb-toc-toggle-btn:hover { color: var(--accent); background: rgba(108,92,231,0.05); border-top-color: var(--border); }
        .kb-toc-panel.collapsed .kb-toc-toggle-btn { transform: rotate(180deg); border-top: none; }
        .kb-toc-panel.collapsed:hover .kb-toc-toggle-btn { color: var(--accent); }
        /* 展开竖条 */
        .kb-toc-expand-bar {
            display: none;
            width: 28px; flex-shrink: 0;
            align-items: center; justify-content: center;
            writing-mode: vertical-rl;
            text-orientation: mixed;
            font-size: 0.75em; letter-spacing: 2px;
            color: var(--text-muted); cursor: pointer;
            border-right: 1px solid var(--border);
            background: var(--card); z-index: 5;
            align-self: flex-start;
            padding: 20px 0;
        }
        .kb-toc-expand-bar:hover { color: var(--accent); background: rgba(108,92,231,0.05); }
        .kb-article.toc-collapsed .kb-toc-expand-bar { display: flex; }
        .kb-article.toc-collapsed .kb-toc-panel { display: none; }
        .kb-article.toc-collapsed .kb-article-inner { padding-left: 48px; }
        .kb-toc-title {
            font-size: 0.7em; color: var(--text-muted);
            text-transform: uppercase; letter-spacing: 1px;
            margin-bottom: 10px; padding: 0 14px;
        }
        .kb-toc-list { list-style: none; padding: 0; margin: 0; }
        .kb-toc-item {
            display: flex; align-items: center; gap: 4px;
            padding: 3px 10px;
            font-size: 0.85em; color: var(--text-secondary); font-weight: 600;
            cursor: pointer; border-left: 2px solid transparent;
            transition: all 0.15s;
            white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
        }
        .kb-toc-item:hover { color: var(--accent); background: rgba(108,92,231,0.05); }
        .kb-toc-item.active { color: var(--accent); border-left-color: var(--accent); background: rgba(108,92,231,0.08); font-weight: 700; }
        .kb-toc-item.h2 { padding-left: 26px; font-size: 0.82em; font-weight: 500; }
        .kb-toc-item.h3 { padding-left: 42px; font-size: 0.8em; font-weight: 400; opacity: 0.85; }
        /* 箭头 */
        .kb-toc-arrow {
            display: inline-flex; align-items: center; justify-content: center;
            width: 16px; height: 16px; flex-shrink: 0;
            cursor: pointer; transition: transform 0.2s;
            color: var(--text-muted); font-size: 0.7em;
            user-select: none;
        }
        .kb-toc-arrow:hover { color: var(--accent); }
        .kb-toc-arrow svg { width: 10px; height: 10px; fill: currentColor; }
        .kb-toc-arrow.collapsed { transform: rotate(-90deg); }
        .kb-toc-item.hidden-child { display: none !important; }
        .kb-article-inner { flex: 1; padding: 30px 40px; min-width: 0; position: relative; }
        /* ========== 图片编辑 - 拖拽缩放 ========== */
        .kb-img-selected { outline: 2px solid var(--accent); position: relative; }
        .kb-img-resize-handle {
            position: absolute; bottom: -1px; right: -1px; width: 14px; height: 14px;
            background: var(--accent); cursor: nwse-resize; border-radius: 2px 0 2px 0;
            z-index: 10; opacity: 0.85;
        }
        .kb-img-resize-handle:hover { opacity: 1; }

        /* 知识库编辑模式 - 腾讯文档风格 */
        .kb-sidebar-edit-bar { display: flex; align-items: center; justify-content: space-between; padding: 8px 12px; background: rgba(108,92,231,0.08); border-bottom: 1px solid var(--border); }
        .kb-edit-toggle { display: flex; align-items: center; gap: 6px; padding: 3px 10px; border-radius: 6px; font-size: 0.7em; font-weight: 600; cursor: pointer; border: 1px solid var(--border); background: transparent; color: var(--text-secondary); transition: all 0.2s; }
        .kb-edit-toggle:hover { border-color: var(--accent); color: var(--accent); }
        .kb-edit-toggle.active { background: var(--accent); color: #fff; border-color: var(--accent); }
        .kb-edit-actions { display: flex; gap: 4px; }
        .kb-edit-btn { width: 28px; height: 28px; border-radius: 6px; border: 1px solid var(--border); background: transparent; color: var(--text-muted); cursor: pointer; font-size: 0.85em; display: flex; align-items: center; justify-content: center; transition: all 0.2s; }
        .kb-edit-btn:hover { border-color: var(--accent); color: var(--accent); background: rgba(108,92,231,0.08); }
        .kb-edit-btn.danger:hover { border-color: var(--danger); color: var(--danger); background: rgba(232,120,74,0.08); }
        .kb-tree-node.editing { cursor: grab; }
        .kb-tree-node.editing:active { cursor: grabbing; }
        .kb-tree-node.editing .kb-tree-toggle,
        .kb-tree-node.editing .kb-tree-leaf { padding-right: 58px; }
        .kb-tree-node.editing .kb-tree-toggle .kb-tree-arrow,
        .kb-tree-node.editing .kb-tree-toggle .kb-tree-icon,
        .kb-tree-node.editing .kb-tree-leaf .kb-tree-leaf-icon { cursor: pointer; }
        .kb-tree-node.editing .kb-node-title { cursor: text; }
        /* 操作按钮：hover才显示 */
        .kb-node-actions { position: absolute; right: 4px; top: 50%; transform: translateY(-50%); display: flex; gap: 2px; opacity: 0; transition: opacity 0.15s; z-index: 5; background: var(--bg-card); border-radius: 4px; padding: 1px; }
        .kb-tree-node:hover > .kb-tree-toggle .kb-node-actions,
        .kb-tree-node:hover > .kb-tree-leaf .kb-node-actions { opacity: 1; }
        .kb-node-action-btn { width: 22px; height: 22px; border-radius: 4px; border: none; background: var(--bg-main); color: var(--text-muted); cursor: pointer; font-size: 0.7em; display: flex; align-items: center; justify-content: center; transition: all 0.15s; }
        .kb-node-action-btn:hover { color: var(--accent); background: rgba(108,92,231,0.15); }
        .kb-node-action-btn.del:hover { color: var(--danger); background: rgba(232,120,74,0.15); }
        .kb-rename-input { background: var(--bg-main); border: 1px solid var(--accent); color: var(--text-primary); padding: 2px 6px; border-radius: 4px; font-size: 0.88em; width: 140px; outline: none; }
        .kb-add-menu { position: absolute; left: 20px; top: 100%; z-index: 20; background: var(--bg-card); border: 1px solid var(--border); border-radius: 6px; overflow: hidden; box-shadow: var(--shadow-lg); display: none; }
        .kb-add-menu.show { display: block; }
        .kb-add-menu-item { padding: 8px 16px; font-size: 0.85em; cursor: pointer; color: var(--text-secondary); transition: all 0.15s; white-space: nowrap; }
        .kb-add-menu-item:hover { background: rgba(108,92,231,0.1); color: var(--accent); }
        /* 拖拽三区域指示线 */
        .kb-tree-node.drag-over-top { border-top: 2px solid var(--accent) !important; }
        .kb-tree-node.drag-over-bottom { border-bottom: 2px solid var(--accent) !important; }
        .kb-tree-node.drag-over-inside > .kb-tree-toggle,
        .kb-tree-node.drag-over-inside > .kb-tree-leaf { background: rgba(108,92,231,0.15) !important; border-radius: 6px; }
        .kb-tree-node.dragging { opacity: 0.4; }
        .kb-node-title.editable { cursor: text; border-bottom: 1px dashed transparent; transition: border-color 0.15s; }
        .kb-node-title.editable:hover { border-bottom-color: var(--accent); }
        /* 右键菜单 */
        .kb-context-menu { position: fixed; z-index: 200; background: var(--bg-card); border: 1px solid var(--border); border-radius: 6px; overflow: hidden; box-shadow: 0 8px 32px rgba(0,0,0,0.5); min-width: 160px; padding: 4px 0; }
        .kb-context-menu-item { padding: 8px 16px; font-size: 0.85em; cursor: pointer; color: var(--text-secondary); transition: all 0.12s; display: flex; align-items: center; gap: 8px; white-space: nowrap; }
        .kb-context-menu-item:hover { background: rgba(108,92,231,0.1); color: var(--accent); }
        .kb-context-menu-item.danger:hover { background: rgba(232,120,74,0.1); color: var(--danger); }
        .kb-context-menu-sep { height: 1px; background: var(--border); margin: 4px 8px; }
        /* 悬浮+按钮 */
.kb-icon-picker { position: fixed; z-index: 210; background: var(--bg-card); border: 1px solid var(--border); border-radius: 10px; overflow: hidden; box-shadow: 0 12px 40px rgba(0,0,0,0.6); width: 320px; }
        .kb-icon-picker-header { display: flex; align-items: center; justify-content: space-between; padding: 10px 14px; border-bottom: 1px solid var(--border); }
        .kb-icon-picker-title { font-size: 0.9em; font-weight: 600; color: var(--text-primary); }
        .kb-icon-picker-close { background: none; border: none; color: var(--text-muted); cursor: pointer; font-size: 1.1em; padding: 2px 6px; border-radius: 4px; }
        .kb-icon-picker-close:hover { background: rgba(255,255,255,0.05); color: var(--text-primary); }
        .kb-icon-picker-search { padding: 8px 14px; border-bottom: 1px solid var(--border); }
        .kb-icon-picker-search input { width: 100%; padding: 6px 10px; border-radius: 6px; border: 1px solid var(--border); background: var(--bg-body); color: var(--text-primary); font-size: 0.85em; outline: none; }
        .kb-icon-picker-search input:focus { border-color: var(--accent); }
        .kb-icon-picker-cats { display: flex; gap: 2px; padding: 6px 10px; border-bottom: 1px solid var(--border); overflow-x: auto; }
        .kb-icon-picker-cat { padding: 3px 8px; border-radius: 6px; font-size: 0.7em; color: var(--text-muted); cursor: pointer; white-space: nowrap; transition: all 0.12s; }
        .kb-icon-picker-cat:hover { color: var(--text-primary); background: rgba(255,255,255,0.05); }
        .kb-icon-picker-cat.active { color: var(--accent); background: rgba(108,92,231,0.1); font-weight: 500; }
        .kb-icon-picker-grid { display: grid; grid-template-columns: repeat(8, 1fr); gap: 4px; padding: 10px; max-height: 240px; overflow-y: auto; }
        .kb-icon-picker-item { display: flex; align-items: center; justify-content: center; height: 34px; border-radius: 6px; cursor: pointer; font-size: 1.3em; transition: all 0.1s; }
        .kb-icon-picker-item:hover { background: rgba(108,92,231,0.15); transform: scale(1.15); }
        .kb-icon-picker-backdrop { position: fixed; inset: 0; z-index: 205; }
        .kb-hover-add { position: absolute; right: 4px; top: 50%; transform: translateY(-50%); width: 20px; height: 20px; border-radius: 50%; border: 1px solid var(--border); background: var(--bg-card); color: var(--text-muted); cursor: pointer; font-size: 0.75em; display: flex; align-items: center; justify-content: center; opacity: 0; transition: all 0.15s; z-index: 4; }
        .kb-tree-node:hover > .kb-tree-toggle .kb-hover-add,
        .kb-tree-node:hover > .kb-tree-leaf .kb-hover-add { opacity: 1; }
        .kb-hover-add:hover { border-color: var(--accent); color: var(--accent); background: rgba(108,92,231,0.1); }

        /* === 三点菜单（腾讯文档风格） === */
        .kb-three-dot-btn { position: absolute; right: 28px; top: 50%; transform: translateY(-50%); width: 26px; height: 26px; border-radius: 6px; border: none; background: transparent; color: var(--text-muted); cursor: pointer; font-size: 1.1em; display: flex; align-items: center; justify-content: center; opacity: 0; transition: all 0.15s; z-index: 5; letter-spacing: 1px; }
        .kb-tree-node:hover > .kb-tree-toggle .kb-three-dot-btn,
        .kb-tree-node:hover > .kb-tree-leaf .kb-three-dot-btn { opacity: 1; }
        .kb-three-dot-btn:hover { background: rgba(255,255,255,0.06); color: var(--text-primary); }
        .kb-three-dot-btn.active { opacity: 1; background: rgba(255,255,255,0.06); color: var(--text-primary); }

        /* 三点下拉菜单 */
        .kb-three-dot-menu { position: fixed; z-index: 210; background: #28283A; border: 1px solid rgba(255,255,255,0.08); border-radius: 10px; overflow: hidden; box-shadow: 0 8px 32px rgba(0,0,0,0.55); min-width: 180px; padding: 6px 0; }
        .kb-three-dot-menu-item { padding: 9px 16px; font-size: 0.86em; cursor: pointer; color: #c8ccd4; transition: all 0.12s; display: flex; align-items: center; gap: 10px; white-space: nowrap; user-select: none; }
        .kb-three-dot-menu-item:hover { background: rgba(108,92,231,0.1); color: #fff; }
        .kb-three-dot-menu-item.danger { color: #ff6b6b; }
        .kb-three-dot-menu-item.danger:hover { background: rgba(255,107,107,0.12); color: #ff6b6b; }
        .kb-three-dot-menu-icon { width: 18px; text-align: center; font-size: 1em; opacity: 0.7; flex-shrink: 0; }
        .kb-three-dot-menu-sep { height: 1px; background: rgba(255,255,255,0.06); margin: 4px 8px; }
        .kb-three-dot-menu-footer { padding: 6px 16px; font-size: 0.75em; color: var(--text-muted); display: flex; align-items: center; gap: 6px; }
        .kb-three-dot-menu-footer-icon { font-size: 0.9em; }
        .kb-three-dot-menu-backdrop { position: fixed; inset: 0; z-index: 209; }

        /* === 知识库 网盘风格侧边栏 === */
        /* 左侧导航栏已有知识库树，隐藏内联侧边栏 */
        #knowledgeView .kb-sidebar { display: none; }
        #knowledgeView .kb-sidebar-header { background: var(--bg-card); color: var(--text-primary); border-bottom-color: var(--border); padding: 12px 16px; }
        #knowledgeView .kb-sidebar-header span { color: var(--text-secondary); }
        #knowledgeView .kb-tree { padding: 8px 0; }
        /* 分组标题 */
        #knowledgeView .kb-tree-section-title { padding: 16px 16px 8px; font-size: 0.75em; color: var(--text-muted); font-weight: 500; }
        /* 树节点通用样式 */
        #knowledgeView .kb-tree-toggle,
        #knowledgeView .kb-tree-leaf { 
            color: var(--text-secondary); 
            border-left: none;
            padding: 8px 16px;
            margin: 2px 8px;
            border-radius: 6px;
            display: flex;
            align-items: center;
            gap: 10px;
            font-size: 0.9em;
        }
        #knowledgeView .kb-tree-toggle:hover,
        #knowledgeView .kb-tree-leaf:hover { 
            background: var(--primary-dim); 
            color: var(--text-primary);
        }
        #knowledgeView .kb-tree-toggle.active,
        #knowledgeView .kb-tree-leaf.active { 
            color: #fff; 
            background: var(--accent);
        }
        #knowledgeView .kb-tree-arrow { display: none; }
        #knowledgeView .kb-tree-icon { display: none; }  /* 已改用 kb-node-dot */
        #knowledgeView .kb-node-dot { width: 7px; height: 7px; border-radius: 50%; flex-shrink: 0; margin: 0 2px; }
        #knowledgeView .kb-node-title { flex: 1; }
        /* 右侧计数 */
        #knowledgeView .kb-node-count { 
            color: var(--text-muted); 
            font-size: 0.85em;
            font-variant-numeric: tabular-nums;
        }
        #knowledgeView .kb-sidebar-edit-bar { background: var(--primary-dim); border-bottom-color: var(--border); padding: 8px 16px; }
        #knowledgeView .kb-sidebar-edit-bar span { color: var(--accent); }
        #knowledgeView .kb-edit-toggle { border-color: var(--border); color: var(--text-muted); border-radius: 6px; }
        #knowledgeView .kb-edit-toggle:hover { border-color: var(--accent); color: var(--accent); }
        #knowledgeView .kb-edit-toggle.active { background: var(--accent); color: #fff; border-color: var(--accent); }
        #knowledgeView .kb-edit-btn { border-color: var(--border); color: var(--text-muted); border-radius: 6px; }
        #knowledgeView .kb-edit-btn:hover { border-color: var(--accent); color: var(--accent); background: var(--primary-dim); }
        #knowledgeView .kb-edit-btn.danger:hover { border-color: #e17055; color: #e17055; background: rgba(232,120,74,0.08); }
        #knowledgeView .kb-node-actions { background: var(--bg-dark); }
        #knowledgeView .kb-node-action-btn { background: var(--bg-card); color: var(--text-muted); border-radius: 4px; }
        #knowledgeView .kb-node-action-btn:hover { color: var(--accent); background: var(--primary-dim); }
        #knowledgeView .kb-node-action-btn.del:hover { color: #e17055; background: rgba(232,120,74,0.15); }
        #knowledgeView .kb-rename-input { background: var(--bg-card); border-color: var(--accent); color: var(--text-primary); border-radius: 4px; }
        #knowledgeView .kb-hover-add { background: var(--bg-dark); border-color: var(--border); color: var(--text-muted); border-radius: 4px; }
        #knowledgeView .kb-hover-add:hover { border-color: var(--accent); color: var(--accent); background: var(--primary-dim); }
        #knowledgeView .kb-tree-node.drag-over-top { border-top-color: var(--accent) !important; }
        #knowledgeView .kb-tree-node.drag-over-bottom { border-bottom-color: var(--accent) !important; }
        #knowledgeView .kb-tree-node.drag-over-inside > .kb-tree-toggle,
        #knowledgeView .kb-tree-node.drag-over-inside > .kb-tree-leaf { background: rgba(108,92,231,0.15) !important; }
        #knowledgeView .kb-node-title.editable:hover { border-bottom-color: var(--accent); }
        /* 知识库内容区 - 浅色 */
        #knowledgeView .kb-content { background: var(--bg-card); }
        #knowledgeView .kb-placeholder { background: var(--bg-card); }
        #knowledgeView .kb-placeholder-icon { opacity: 0.3; }
        #knowledgeView .kb-placeholder-title { background: none; -webkit-text-fill-color: var(--text-primary); color: var(--text-primary); }
        #knowledgeView .kb-placeholder-desc { color: var(--text-muted); }
        #knowledgeView .kb-article { background: var(--bg-card); }
        #knowledgeView .kb-article-inner { background: var(--bg-card); }
        #knowledgeView .kb-article-header { border-bottom-color: var(--border); }
        #knowledgeView .kb-article-title { color: var(--text-primary); }
        #knowledgeView .kb-article-path { color: var(--text-muted); }
        #knowledgeView .kb-editor-toolbar { background: var(--bg-dark); border-bottom-color: var(--border); }
        #knowledgeView .kb-editor-btn { color: var(--text-secondary); }
        #knowledgeView .kb-editor-btn:hover { background: rgba(45,212,191,0.08); color: var(--primary); }
        #knowledgeView .kb-editor-btn.active,
        #knowledgeView .kb-editor-btn.kb-format-active { background: var(--primary); color: var(--bg-dark); }
        #knowledgeView .kb-article-body { color: var(--text-primary); background: transparent; }
        #knowledgeView .kb-article-body h1 { color: var(--text-primary); border-bottom-color: var(--border); }
        #knowledgeView .kb-article-body h2,
        #knowledgeView .kb-article-body h3 { color: var(--text-primary); }
        #knowledgeView .kb-article-body.editing { border-color: var(--border); color: var(--text-primary); background: var(--bg-dark); }
        #knowledgeView .kb-article-body:focus { background: rgba(45,212,191,0.02); }
        #knowledgeView .kb-article-body:empty::before { color: var(--text-muted); }
        #knowledgeView .kb-article-body a { color: var(--primary); border-bottom-color: rgba(45,212,191,0.35); pointer-events: auto !important; user-select: text !important; cursor: pointer !important; }
        #knowledgeView .kb-article-body a:hover { background: rgba(45,212,191,0.08); border-bottom-color: var(--primary); box-shadow: none; transform: none; }
        #knowledgeView .kb-article-body a:visited { color: var(--primary-light); border-bottom-color: rgba(94,234,212,0.3); }
        #knowledgeView .kb-article-body table { border-color: var(--border); }
        #knowledgeView .kb-article-body table td,
        #knowledgeView .kb-article-body table th { border-color: var(--border); color: var(--text-secondary); }
        #knowledgeView .kb-article-body table th { background: rgba(45,212,191,0.06); color: var(--text-primary); }
        #knowledgeView .kb-article-body table tr:hover td { background: rgba(45,212,191,0.03); }
        #knowledgeView .kb-toc-panel { background: var(--bg-card); border-right-color: var(--border); }
        #knowledgeView .kb-toc-title { color: var(--text-muted); }
        #knowledgeView .kb-toc-item { color: var(--text-secondary); border-left-color: transparent; }
        #knowledgeView .kb-toc-item:hover { color: var(--primary); background: rgba(45,212,191,0.06); }
        #knowledgeView .kb-toc-item.active { color: var(--primary); border-left-color: var(--primary); background: rgba(45,212,191,0.08); }
        #knowledgeView .kb-toc-arrow { color: var(--text-muted); }
        #knowledgeView .kb-toc-arrow:hover { color: var(--primary); }
        #knowledgeView .kb-toc-expand-bar { background: var(--bg-card); border-right-color: var(--border); color: var(--text-muted); }
        #knowledgeView .kb-toc-expand-bar:hover { color: var(--primary); background: rgba(45,212,191,0.06); }
        #knowledgeView .kb-toc-toggle-btn { color: var(--text-muted); border-top-color: transparent; }
        #knowledgeView .kb-toc-toggle-btn:hover { color: var(--primary); background: rgba(45,212,191,0.06); border-top-color: var(--border); }
        #knowledgeView .kb-article.toc-collapsed .kb-article-inner { padding-left: 48px; }
        .kb-context-menu { background: var(--bg-card); border-color: var(--border); border-radius: 6px; }
        .kb-context-menu-item { color: var(--text-secondary); }
        .kb-context-menu-item:hover { background: rgba(45,212,191,0.08); color: var(--primary); }
        .kb-context-menu-item.danger:hover { background: rgba(239,68,68,0.1); color: var(--danger); }
        .kb-context-menu-sep { background: var(--border); }
        .kb-add-menu { background: var(--bg-card); border-color: var(--border); border-radius: 6px; }
        .kb-add-menu-item { color: var(--text-secondary); }
        .kb-add-menu-item:hover { background: rgba(45,212,191,0.08); color: var(--primary); }
        .kb-icon-picker { background: var(--bg-card); border-color: var(--border); border-radius: 6px; }
        .kb-icon-picker-header { border-bottom-color: var(--border); }
        .kb-icon-picker-title { color: var(--text-secondary); }
        .kb-icon-picker-close { color: var(--text-muted); }
        .kb-icon-picker-close:hover { color: var(--danger); }
        .kb-icon-picker-search { border-bottom-color: var(--border); }
        .kb-icon-picker-search input { background: var(--bg-dark); border-color: var(--border); color: var(--text-primary); }
        .kb-icon-picker-search input:focus { border-color: var(--primary); }
        .kb-icon-picker-cats { border-bottom-color: var(--border); }
        .kb-icon-picker-cat { color: var(--text-muted); }
        .kb-icon-picker-cat:hover { color: var(--text-primary); background: rgba(45,212,191,0.06); }
        .kb-icon-picker-cat.active { color: var(--primary); background: rgba(45,212,191,0.12); }
        .kb-icon-picker-item:hover { background: rgba(45,212,191,0.1); }
        .kb-icon-picker-backdrop { background: rgba(0,0,0,0.45); }
        .kb-link-modal-backdrop { background: rgba(0,0,0,0.45); }
        .kb-link-modal { background: var(--bg-card); border-color: var(--border); }
        .kb-link-modal h3 { color: var(--text-primary); }
        .kb-link-modal-input { background: var(--bg-dark); border-color: var(--border); color: var(--text-primary); }
        .kb-link-modal-input:focus { border-color: var(--primary); }
        .kb-link-btn-cancel { border-color: var(--border); color: var(--text-muted); }
        .kb-link-btn-cancel:hover { background: rgba(45,212,191,0.06); }
        .kb-link-btn-ok { background: var(--primary); color: var(--bg-dark); }
        .kb-link-btn-ok:hover { opacity: 0.85; }
        .kb-class-modal-backdrop { background: rgba(0,0,0,0.45); }
        .kb-class-modal { background: var(--bg-card); border-color: var(--border); }
        .kb-class-modal h3 { color: var(--text-primary); }
        .kb-class-modal-desc { color: var(--text-muted); }
        .kb-class-modal-group-title { color: var(--text-primary); border-bottom-color: var(--border); }
        .kb-class-modal-item { color: var(--text-secondary); }
        .kb-class-modal-item:hover { color: var(--text-primary); }
        .kb-color-picker { background: var(--bg-card); border-color: var(--border); }
        .kb-color-swatch:hover { border-color: var(--text-primary); }
        .kb-table-menu { background: var(--bg-card); border-color: var(--border); }
        .kb-table-menu-item { color: var(--text-secondary); }
        .kb-table-menu-item:hover { background: rgba(45,212,191,0.06); color: var(--primary); }
        .kb-table-menu-sep { background: var(--border); }
        .kb-table-grid-popup { background: var(--bg-card); border-color: var(--border); }
        .kb-table-grid-popup-label { color: var(--text-muted); }
        .kb-table-grid-cell { border-color: var(--text-muted); }
        .kb-table-grid-cell.highlight { background: rgba(45,212,191,0.15); border-color: var(--primary); }
        #knowledgeView .kb-save-indicator { color: var(--text-muted); }
        #knowledgeView .kb-save-indicator.saving { color: #6C5CE7; }
        #knowledgeView .kb-save-indicator.saved { color: #6C5CE7; }
        #knowledgeView .kb-editor-toolbar .sep { background: var(--border); }

        /* 知识库 - 权限拒绝页 */
        .kb-denied { display: flex; flex-direction: column; align-items: center; justify-content: center; min-height: 60vh; padding: 30px 40px; background: #ffffff; }
        .kb-denied-icon { font-size: 4em; margin-bottom: 16px; opacity: 0.4; }
        .kb-denied-title { font-size: 1.4em; margin-bottom: 8px; color: #6b7280; font-weight: 600; }
        .kb-denied-desc { color: #9ca3af; font-size: 0.95em; }

        /* 知识库 - 学员水印 */
        .kb-watermark { position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; pointer-events: none; z-index: 9999; overflow: hidden; display: none; }
        .kb-watermark.show { display: block; }
        .kb-watermark-text { position: absolute; font-size: 16px; color: #000; opacity: 0.1; white-space: nowrap; transform: rotate(-25deg); user-select: none; font-family: "PingFang SC","Microsoft YaHei",sans-serif; letter-spacing: 2px; }

        .user-info { display: none; align-items: center; gap: 10px; }
        .user-info.show { display: flex; }
        .user-avatar-sm { width: 34px; height: 34px; border-radius: 50%; background: linear-gradient(135deg, var(--primary), var(--accent)); display: flex; align-items: center; justify-content: center; font-size: 0.6em; font-weight: 700; flex-direction: column; text-align: center; line-height: 1.2; padding: 2px; word-break: break-all; font-family: "PingFang SC","Microsoft YaHei",sans-serif; box-shadow: 0 2px 8px rgba(124,111,247,0.2); }
        .user-name-sm { font-size: 0.88em; font-weight: 600; color: var(--accent); }
        .admin-indicator { background: rgba(0,214,143,0.15); color: var(--success); padding: 3px 10px; border-radius: 20px; font-size: 0.82em; font-weight: 600; display: none; }
        .admin-indicator.show { display: block; }

        /* === 统一按钮系统 === */
        .btn { display: inline-flex; align-items: center; justify-content: center; gap: 6px; border: none; cursor: pointer; font-weight: 600; font-family: inherit; text-decoration: none; user-select: none; white-space: nowrap; padding: 9px 18px; border-radius: var(--radius); font-size: 0.88em; letter-spacing: 0.3px; transition: all 0.25s cubic-bezier(0.4,0,0.2,1); }
        .btn:hover { transform: translateY(-1px); }
        .btn:active { transform: translateY(0) scale(0.97); }
        .btn:disabled, .btn.disabled { opacity: 0.5; cursor: not-allowed; transform: none; pointer-events: none; }

        .btn-primary { background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: #fff; box-shadow: 0 2px 12px rgba(45,212,191,0.2); }
        .btn-primary:hover { box-shadow: 0 6px 24px rgba(45,212,191,0.35); filter: brightness(1.08); }
        .btn-accent { background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: #fff; box-shadow: 0 2px 12px rgba(45,212,191,0.2); }
        .btn-accent:hover { box-shadow: 0 6px 24px rgba(45,212,191,0.35); filter: brightness(1.08); }

        .btn-outline { background: var(--bg-card); color: var(--text-secondary); border: 1.5px solid var(--border); box-shadow: none; }
        .btn-outline:hover { border-color: var(--primary); color: var(--primary); box-shadow: 0 2px 12px rgba(45,212,191,0.08); }
        .btn-outline.active { background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: #fff; border-color: var(--primary); }

        .btn-success { background: linear-gradient(135deg, var(--success), #00b87a); color: #fff; box-shadow: 0 2px 12px rgba(16,185,129,0.2); }
        .btn-success:hover { box-shadow: 0 6px 24px rgba(16,185,129,0.35); filter: brightness(1.08); }

        .btn-danger { background: linear-gradient(135deg, var(--danger), #FF5252); color: #fff; box-shadow: 0 2px 12px rgba(239,68,68,0.2); }
        .btn-danger:hover { box-shadow: 0 6px 24px rgba(239,68,68,0.35); filter: brightness(1.08); }

        .btn-ghost { background: rgba(124,111,247,0.06); color: var(--text-muted); border: 1px solid transparent; box-shadow: none; }
        .btn-ghost:hover { background: rgba(124,111,247,0.14); color: var(--primary); border-color: rgba(124,111,247,0.25); }
        .btn-ghost.btn-danger:hover { background: rgba(239,68,68,0.14); color: var(--danger); border-color: var(--danger); }

        .btn-sm { padding: 5px 12px; font-size: 0.78em; border-radius: var(--radius-sm); }
        .btn-xs { padding: 3px 8px; font-size: 0.72em; border-radius: 6px; }

        /* === 统一图标系统 === */
        .icon-emoji { display: inline-flex; align-items: center; justify-content: center; width: 1.5em; height: 1.5em; font-size: 1em; line-height: 1; vertical-align: middle; flex-shrink: 0; }
        .icon-svg { display: inline-flex; align-items: center; justify-content: center; flex-shrink: 0; }
        .icon-svg svg { width: 1em; height: 1em; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

        .btn-small { padding: 6px 14px; font-size: 0.82em; border-radius: var(--radius-sm); }
        .btn-tiny { padding: 3px 8px; font-size: 0.75em; border-radius: 6px; }

        /* 兼容旧类名别名 */



        /* === 英雄区域 === */
        .hero { padding: 40px 20px 22px; background: linear-gradient(180deg, rgba(108,92,231,0.06) 0%, rgba(108,92,231,0.02) 40%, transparent 85%); position: relative; overflow: hidden; }
        .hero::before { content: ''; position: absolute; top: -80px; left: 50%; transform: translateX(-50%); width: 500px; height: 200px; background: radial-gradient(ellipse, rgba(108,92,231,0.08) 0%, transparent 70%); pointer-events: none; }
        .hero h2 { font-size: 1.8em; margin-bottom: 8px; background: linear-gradient(135deg, var(--accent), var(--primary), var(--accent2)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; text-align: center; position: relative; }
        .hero p { color: var(--text-secondary); margin-bottom: 18px; font-size: 0.95em; text-align: center; position: relative; }

        /* === 统计 === */
        .stats-row { display: flex; justify-content: center; gap: 16px; padding: 14px 20px; flex-wrap: wrap; }
        .stat-item { text-align: center; padding: 14px 24px; background: var(--glass-bg); border-radius: var(--radius-lg); border: 1px solid var(--glass-border); min-width: 105px; backdrop-filter: blur(8px); transition: all 0.3s ease; }
        .stat-item:hover { transform: translateY(-2px); border-color: var(--border-glow); box-shadow: var(--shadow-glow); }
        .stat-item .num { font-size: 2.1em; font-weight: 800; background: linear-gradient(135deg, var(--accent), var(--primary)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
        .stat-item .num.warning-num { background: linear-gradient(135deg, var(--warning), var(--danger)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
        .stat-item .desc { color: var(--text-muted); font-size: 0.8em; margin-top: 2px; font-weight: 500; }

        /* === 老师/学员工具栏 === */
        .toolbar { display: none; background: linear-gradient(180deg, rgba(108,92,231,0.04) 0%, rgba(108,92,231,0.01) 40%, transparent 100%); border: none; padding: 14px 20px; margin: 0; border-bottom: 1px solid rgba(108,92,231,0.06); }
        .toolbar.show { display: block; }
        .toolbar-row { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; justify-content: center; }
        .toolbar h3 { margin: 0; font-size: 0.95em; white-space: nowrap; }
        .toolbar h3.admin-title { color: var(--success); }
        .toolbar h3.student-title { color: var(--accent); }
        .toolbar-stats { display: flex; gap: 8px; flex-wrap: wrap; }
        .toolbar-stat-chip { display: flex; align-items: center; gap: 5px; padding: 3px 10px; background: var(--bg-dark); border-radius: 12px; font-size: 0.82em; border: 1px solid var(--border); }
        .toolbar-stat-chip .dot { width: 7px; height: 7px; border-radius: 50%; }
        .toolbar-actions { display: flex; gap: 8px; flex-wrap: wrap; }

        /* === 筛选 === */
        .filter-row { display: flex; gap: 8px; flex-wrap: wrap; align-items: center; justify-content: center; }
        .filter-row-status { padding-top: 6px; border-top: 1px solid var(--border); margin-top: 6px; }
        .filter-tag { padding: 6px 16px; border: 1.5px solid var(--border); border-radius: 20px; font-size: 0.83em; cursor: pointer; transition: all 0.3s ease; color: var(--text-secondary); font-weight: 500; }
        .filter-tag:hover, .filter-tag.active { border-color: var(--primary); color: var(--primary); background: rgba(124,111,247,0.12); box-shadow: 0 0 16px rgba(124,111,247,0.1); transform: translateY(-1px); }

        /* === 主内容 === */
        .main-content { margin: 0; padding: 0 20px; }

        /* === 缩略图网格 === */
        .thumbnail-grid { display: grid; grid-template-columns: repeat(auto-fill, 280px); gap: 12px; padding: 4px 0 36px 16px; justify-content: start; }
        .thumb-card { width: 280px; background: var(--bg-card); border-radius: 10px; border: 1px solid var(--border); overflow: hidden; cursor: pointer; transition: all 0.25s cubic-bezier(0.4,0,0.2,1); position: relative; animation: fadeInUp 0.35s ease forwards; flex-shrink: 0; }
        .thumb-card:hover { transform: translateY(-4px); border-color: var(--border-glow); box-shadow: 0 6px 20px rgba(0,0,0,0.15), 0 0 0 1px rgba(108,92,231,0.06); }
        /* === 我的帖子突出显示 === */
        .thumb-card.my-post {
            border: 2px solid var(--accent);
            box-shadow: 0 0 20px rgba(108,92,231,0.15), 0 4px 20px rgba(0,0,0,0.06);
            position: relative;
        }
        .thumb-card.my-post:hover { border-color: var(--primary); box-shadow: 0 0 20px rgba(108,92,231,0.15), 0 4px 15px rgba(0,0,0,0.08); transform: translateY(-3px); }
        .thumb-card.my-post .thumb-image img {
            filter: brightness(1.05) saturate(1.1);
        }
        .my-post-badge {
            position: absolute;
            top: 8px;
            left: 12px;
            z-index: 10;
            background: linear-gradient(135deg, var(--primary), #5A4BD1);
            color: #fff;
            font-weight: 700;
            font-size: 0.7em;
            padding: 3px 10px;
            border-radius: 6px;
            letter-spacing: 0.5px;
            box-shadow: 0 3px 14px rgba(0,212,204,0.45);
        }
        .thumb-new-badge { position: absolute; top: 8px; right: 8px; z-index: 10; background: var(--new-glow); color: #fff; font-weight: 700; font-size: 0.7em; padding: 3px 10px; border-radius: 6px; letter-spacing: 1px; animation: newPulse 2s ease-in-out infinite; box-shadow: 0 0 16px rgba(255,71,87,0.4); }
        @keyframes newPulse { 0%,100% { box-shadow: 0 0 10px rgba(255,71,87,0.35); } 50% { box-shadow: 0 0 24px rgba(255,71,87,0.65); } }
        @keyframes reviewingPulse { 0%,100% { box-shadow: 0 0 8px rgba(59,130,246,0.25); } 50% { box-shadow: 0 0 18px rgba(59,130,246,0.5); } }
        .thumb-feedback-badge { position: absolute; top: 8px; right: 8px; z-index: 10; background: rgba(59,130,246,0.9); color: #fff; font-weight: 700; font-size: 0.7em; padding: 3px 8px; border-radius: 6px; display: flex; align-items: center; gap: 4px; }
        .thumb-reviewing-badge { position: absolute; top: 8px; right: 8px; z-index: 10; background: rgba(59,130,246,0.9); color: #fff; font-weight: 700; font-size: 0.7em; padding: 3px 8px; border-radius: 6px; display: flex; align-items: center; gap: 4px; animation: reviewingPulse 2.5s ease-in-out infinite; box-shadow: 0 0 12px rgba(59,130,246,0.35); }
        .thumb-resolved-badge { position: absolute; top: 8px; right: 8px; z-index: 10; background: rgba(120,120,140,0.75); color: rgba(255,255,255,0.85); font-weight: 700; font-size: 0.7em; padding: 3px 8px; border-radius: 6px; display: flex; align-items: center; gap: 4px; }
.thumb-done-badge { position: absolute; top: 8px; right: 8px; z-index: 10; background: linear-gradient(135deg,#e8b730,#d4940a); color: #fff; font-weight: 700; font-size: 0.7em; padding: 3px 8px; border-radius: 6px; display: flex; align-items: center; gap: 4px; box-shadow: 0 0 8px rgba(232,183,48,0.4); }
.thumb-live-pending { position: absolute; top: 8px; right: 8px; z-index: 10; background: rgba(255,50,50,0.92); color: #fff; font-weight: 700; font-size: 0.7em; padding: 3px 8px; border-radius: 6px; letter-spacing: 1px; cursor: default; box-shadow: 0 0 12px rgba(255,50,50,0.5); }
        .thumb-image { width: 100%; height: 130px; overflow: hidden; position: relative; background: linear-gradient(180deg, rgba(14,14,31,0) 0%, rgba(24,24,53,0.6) 100%); }
        .thumb-image img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.5s cubic-bezier(0.4,0,0.2,1); }
        .thumb-card:hover .thumb-image img { transform: scale(1.08); }
        .thumb-image .overlay { position: absolute; bottom: 0; left: 0; right: 0; height: 40%; background: linear-gradient(transparent, rgba(14,14,31,0.7)); pointer-events: none; }
        .thumb-image .category-tag { position: absolute; bottom: 8px; left: 10px; padding: 3px 10px; border-radius: 6px; font-size: 0.74em; font-weight: 700; color: #ffffff !important; background: rgba(0,0,0,0.82); backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px); border: 1px solid rgba(255,255,255,0.3); text-shadow: 0 1px 3px rgba(0,0,0,0.6); letter-spacing: 0.3px; }
        .thumb-info { padding: 8px 10px; }
        .thumb-title { font-weight: 700; font-size: 0.85em; line-height: 1.3; margin-bottom: 6px; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; color: var(--text-primary); }
        .thumb-meta { display: flex; justify-content: space-between; align-items: center; gap: 6px; flex-wrap: nowrap; min-width: 0; }
        .thumb-author { display: flex; align-items: center; gap: 4px; cursor: pointer; border-radius: 10px; padding: 1px 4px 1px 1px; transition: background 0.2s; min-width: 0; }
        .thumb-author:hover { background: rgba(108,92,231,0.12); }
        .thumb-avatar { width: 20px; height: 20px; border-radius: 50%; background: linear-gradient(135deg, var(--primary), var(--accent)); display: flex; align-items: center; justify-content: center; font-size: 0.5em; font-weight: 700; flex-shrink: 0; }
        .thumb-author-name { max-width: 100px; font-size: 0.75em; color: var(--text-secondary); font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
        .thumb-time { font-size: 0.7em; color: var(--text-muted); white-space: nowrap; flex-shrink: 0; }
        .thumb-footer { display: none; }
        .thumb-floor-count { display: none; }
        .thumb-floor-count span { color: var(--primary); font-weight: 700; }
        .thumb-progress { display: none; }
        .thumb-card.status-pending { border-color: rgba(255,71,87,0.35); }
        .thumb-card.status-pending:hover { border-color: rgba(255,71,87,0.6); box-shadow: 0 8px 30px rgba(255,71,87,0.15); }
        .thumb-card.status-feedback { border-color: rgba(59,130,246,0.25); }
        .thumb-card.status-resolved { border-color: rgba(116,185,255,0.25); opacity: 0.85; }
        .thumb-card.status-resolved:hover { opacity: 1; }
        .sort-info { display: none !important; }

        /* === 状态筛选栏 === */
        .status-filter-bar { display: flex; align-items: center; gap: 8px; padding: 10px 4px 12px 16px; flex-wrap: wrap; }
        .status-filter-label { font-size: 0.8em; color: var(--text-muted); font-weight: 600; white-space: nowrap; margin-right: 4px; }
        .status-filter-btn { display: inline-flex; align-items: center; gap: 5px; padding: 5px 12px; border-radius: 20px; border: 1px solid var(--border); background: transparent; color: var(--text-secondary); font-size: 0.82em; font-weight: 500; cursor: pointer; transition: all 0.18s; white-space: nowrap; }
        .status-filter-btn:hover { border-color: var(--accent); color: var(--text-primary); background: rgba(108,92,231,0.06); }
        .status-filter-btn.active { background: var(--text-primary); color: var(--bg-main); border-color: var(--text-primary); font-weight: 700; }
        .status-filter-count { font-size: 0.9em; opacity: 0.85; }

        /* === 功能测试聚合卡片 === */
        .feature-test-card .thumb-info { padding: 10px 12px; }
        .feature-test-card .ft-title { font-weight: 600; font-size: 0.75em; line-height: 1.35; margin-bottom: 8px; color: var(--text-primary); display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }
        .feature-test-card .thumb-meta { margin-top: 4px; }
        .feature-test-card .thumb-author-name { max-width: 120px; }

        .hw-detail-layout { display: flex; height: calc(100vh - 56px); overflow: hidden; background: var(--bg-body); }
        .hw-detail-middle { flex: 0 0 34%; max-width: 440px; overflow-y: auto; padding: 16px; background: var(--bg-body); min-width: 280px; }
        .hw-detail-right { flex: 1; min-width: 0; background: var(--bg-card); border-left: 1px solid var(--border); overflow-y: auto; display: flex; flex-direction: column; }
        .hw-detail-topbar { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 16px; padding-bottom: 12px; border-bottom: 1px solid var(--border); flex-wrap: wrap; }
        .hw-submission-sidebar { margin-top: 4px; }
        .hw-submission-sidebar .sb-section-title { margin: 8px 0 6px; }
        .hw-submission-sidebar .hw-submission-list { max-height: 280px; overflow-y: auto; }
        .hw-submission-item { padding: 8px 4px; cursor: pointer; transition: all 0.15s; border-left: 3px solid transparent; border-radius: 6px; margin-bottom: 2px; }
        .hw-submission-item.active { border-left-color: var(--accent); background: rgba(108,92,231,0.06); }
        .hw-submission-item:hover { background: rgba(108,92,231,0.04); }
        .hw-submission-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: 12px; padding: 20px; margin-bottom: 20px; box-shadow: 0 2px 8px rgba(0,0,0,0.04); scroll-margin-top: 16px; }
        .hw-submission-images { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; margin-top: 12px; }
        .hw-submission-images.expert-mode { grid-template-columns: 1fr !important; }
        .hw-submission-images.single { grid-template-columns: 1fr; }
        .hw-submission-image-cell { border-radius: 8px; overflow: hidden; border: 1px solid var(--border); background: var(--bg-sidebar); cursor: pointer; min-height: 140px; display: flex; align-items: center; justify-content: center; }
        .hw-submission-image-cell img { width: 100%; height: 100%; max-height: 360px; object-fit: contain; display: block; background: #111; }
        .hw-submission-images.triple .hw-submission-image-cell:last-child { grid-column: 1 / -1; max-height: 280px; }
        .hw-submission-images.expert-mode .hw-submission-image-cell { grid-column: auto; max-height: 480px; }
        .hw-card-comment { margin-top: 16px; padding-top: 16px; border-top: 1px dashed var(--border); user-select: text; }
        .hw-card-comment textarea { width: 100%; min-height: 72px; padding: 10px 12px; border: 1px solid var(--border); border-radius: 8px; background: var(--bg-dark); color: var(--text-primary); font-size: 0.88em; resize: vertical; font-family: inherit; }
        .hw-card-comment-readonly { padding: 10px 12px; background: var(--bg-sidebar); border-radius: 8px; font-size: 0.88em; color: var(--text-secondary); line-height: 1.6; min-height: 40px; user-select: text !important; cursor: text !important; }
        .hw-comment-delete-btn { margin-left: auto; background: transparent; color: var(--text-muted); border: none; border-radius: 50%; width: 22px; height: 22px; font-size: 12px; cursor: pointer; line-height: 22px; text-align: center; padding: 0; opacity: 0.35; transition: all 0.15s; flex-shrink: 0; }
        .hw-comment-delete-btn:hover { opacity: 1; color: #fff; background: var(--danger); transform: scale(1.1); }
        .hw-steps-bar { display: flex; gap: 10px; overflow-x: auto; padding: 12px 16px; border-bottom: 1px solid var(--border); }
        .hw-step-chip { flex-shrink: 0; width: 88px; text-align: center; }
        .hw-step-chip img { width: 72px; height: 54px; object-fit: cover; border-radius: 6px; border: 1px solid var(--border); cursor: pointer; background: var(--bg-sidebar); }
        .hw-step-chip .step-name { font-size: 0.72em; color: var(--text-secondary); margin-top: 4px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
        .hw-step-add { flex-shrink: 0; width: 72px; height: 54px; border: 1px dashed var(--border); border-radius: 6px; display: flex; align-items: center; justify-content: center; cursor: pointer; color: var(--accent); font-size: 1.4em; background: rgba(108,92,231,0.04); }
        .hw-step-add-disabled { opacity: 0.4; cursor: not-allowed; pointer-events: none; }
        .hw-feedback-filters { display: flex; flex-wrap: wrap; gap: 6px; padding: 10px 16px; border-bottom: 1px solid var(--border); }
        .hw-feedback-filters span { font-size: 0.75em; padding: 4px 10px; border-radius: 14px; cursor: pointer; border: 1px solid var(--border); color: var(--text-secondary); transition: all 0.15s; }
        .hw-feedback-filters span.active { background: var(--accent); color: #fff; border-color: var(--accent); }
        .hw-feedback-table { width: 100%; border-collapse: separate; border-spacing: 0; font-size: 0.78em; background: #fff; border: 1px solid #d0d0d0; border-radius: 6px; overflow: hidden; position: relative; }
        /* 伪元素兜底竖线（不依赖 box-shadow，浏览器兼容性最好） */
        .hw-feedback-table thead tr th, .hw-feedback-table tbody tr td { box-shadow: inset -1px 0 #d0d0d0, inset 0 -1px #d0d0d0; }
        .hw-feedback-table thead tr th::after, .hw-feedback-table tbody tr td::after { content: ''; position: absolute; right: 0; top: 0; bottom: 0; width: 1px; background: #d0d0d0; pointer-events: none; }
        .hw-feedback-table thead tr th:last-child::after, .hw-feedback-table tbody tr td:last-child::after { display: none; }
        .hw-feedback-table thead tr th { position: sticky; top: 0; z-index: 2; background: #f7f7f7; padding: 8px 6px; font-weight: 600; color: var(--text-primary); text-align: left; box-shadow: inset -1px 0 #d0d0d0, inset 0 -2px #b0b0b0; }
        /* 最后一列：去掉右内阴影（避免和表格外框重复），但 th 要保留 2px 深色下边框，td 保留 1px 浅色下边框 */
        .hw-feedback-table thead tr th:last-child { box-shadow: inset 0 -2px #b0b0b0; }
        .hw-feedback-table tbody tr td:last-child { box-shadow: inset 0 -1px #d0d0d0; }
        .hw-feedback-table tbody tr:last-child td { box-shadow: inset -1px 0 #d0d0d0; }
        .hw-feedback-table tbody tr:last-child td:last-child { box-shadow: none; }
        .hw-feedback-empty-row:hover { background: #fafafa !important; }
        .hw-feedback-empty-row td { cursor: context-menu; }
        .hw-feedback-table input, .hw-feedback-table textarea, .hw-feedback-table select { width: 100%; padding: 5px 7px; border: 1px solid var(--border); border-radius: 6px; background: #fff; color: var(--text-primary); font-size: 0.92em; font-family: inherit; }
        /* 状态列：与参考方向1/2 单元格保持同样尺寸和样式（120px 高、仅靠 cell 自身的 box-shadow 形成边框，避免双线） */
        .hw-feedback-table td[data-field="status"] { padding: 0; vertical-align: middle; }
        .hw-feedback-table td[data-field="status"] select { height: 120px; max-height: 120px; min-height: 120px; border: none; border-radius: 0; padding: 8px; font-size: 0.95em; text-align: center; text-align-last: center; cursor: pointer; box-shadow: none; outline: none; }
        .hw-feedback-table td[data-field="status"] select:focus { filter: brightness(0.85); }
        .hw-feedback-table td[data-field="status"] > span.hw-feedback-status-text { display: flex; align-items: center; justify-content: center; min-height: 120px; height: 100%; border: none; background: transparent; color: var(--text-primary); font-size: 0.95em; }
        .hw-feedback-text { white-space: pre-wrap; word-break: break-word; line-height: 1.5; color: var(--text-primary); }
        .hw-feedback-empty { color: #bbb; font-size: 0.95em; }
        .hw-feedback-link { color: var(--accent); text-decoration: none; word-break: break-all; font-size: 0.95em; }
        .hw-feedback-link:hover { text-decoration: underline; }
        .hw-feedback-editable { cursor: text; display: block; outline: none; }
        .hw-feedback-editable:focus { outline: none; box-shadow: none; caret-color: var(--accent); }
        .hw-knowledge-cell { display: block; cursor: pointer; }
        .hw-knowledge-cell:hover { background: #f5f7ff; }
        .hw-knowledge-cell input { outline: none; }
        /* 鼠标悬停整单元格：浅蓝底 */
        .hw-feedback-table td:has(.hw-feedback-editable):hover { background: #f5f7ff; }
        /* 编辑中：去掉 td 自身网格线（避免看起来像"边框"） */
        .hw-feedback-table td:has(.hw-feedback-editable.is-editing) { box-shadow: none; background: #fffbe6; }
        .hw-feedback-table textarea { min-height: 56px; resize: vertical; }
        .hw-feedback-thumb { width: 100%; height: 120px; max-height: 120px; object-fit: cover; border-radius: 0; cursor: pointer; background: #f5f5f5; display: block; }
        .hw-feedback-thumb-empty { width: 100%; height: 120px; max-height: 120px; min-width: 160px; border: 1px dashed #c0c0c0; border-radius: 0; display: flex; align-items: center; justify-content: center; font-size: 0.95em; color: #999; cursor: pointer; background: #fafafa; }
        .hw-feedback-table td[data-field="screenshot"] { padding: 0; width: 160px; min-width: 160px; max-width: 160px; vertical-align: middle; height: 120px; }
        .hw-feedback-table td[data-field="ref1"], .hw-feedback-table td[data-field="ref2"] { padding: 0; width: 160px; min-width: 160px; max-width: 160px; vertical-align: middle; height: 120px; }
        /* 图片单元格聚焦提示（支持 Ctrl+V 粘贴上传） */
        .hw-feedback-table td[data-field="screenshot"]:focus-within,
        .hw-feedback-table td[data-field="screenshot"]:focus,
        .hw-feedback-table td[data-field="ref1"]:focus-within,
        .hw-feedback-table td[data-field="ref1"]:focus,
        .hw-feedback-table td[data-field="ref2"]:focus-within,
        .hw-feedback-table td[data-field="ref2"]:focus { outline: 2px solid var(--accent); outline-offset: -2px; }
        .hw-feedback-table td[data-field="description"] { vertical-align: middle; min-width: 200px; }
        .hw-feedback-table td[data-field="knowledge"] { vertical-align: middle; min-width: 140px; }
        .hw-feedback-table td[data-field="status"] { text-align: center; min-width: 110px; vertical-align: middle; }
        .hw-feedback-table td[data-field="status"] select { border: none; background: transparent; outline: none; padding: 4px 6px; cursor: pointer; text-align: center; text-align-last: center; }
        .hw-feedback-table td[data-field="status"] select:focus { filter: brightness(0.85); border-radius: 4px; }
        .hw-feedback-table tbody td { vertical-align: middle; }
        .hw-feedback-fallback { background: #fff; }
        /* .hw-detail-header { padding: 12px 16px; border-bottom: 1px solid var(--border); display: flex; align-items: center; justify-content: space-between; gap: 12px; flex-wrap: wrap; } */

        /* === 原生表右键菜单 === */
        .hw-feedback-fallback tr[data-row-id] { cursor: default; }
        .hw-feedback-fallback tr[data-row-id] td { user-select: none; }
        .hw-ctx-menu { position: fixed; z-index: 99999; list-style: none; margin: 0; padding: 4px 0; background: var(--bg-card); border: 1px solid var(--border); border-radius: 8px; box-shadow: 0 6px 24px rgba(0,0,0,0.4); min-width: 180px; }
        .hw-ctx-menu li { padding: 8px 14px; font-size: 0.85em; color: var(--text-primary); cursor: pointer; transition: all 0.12s; }
        .hw-ctx-menu li:hover { background: var(--accent); color: #fff; }
        .hw-ctx-menu .hw-ctx-divider { padding: 0; margin: 4px 8px; height: 1px; background: var(--border); cursor: default; }
        .hw-ctx-menu .hw-ctx-divider:hover { background: var(--border); }

        /* === 详情视图 === */
        .detail-view { display: none; }
        .detail-view.show { display: block; }
        .detail-view .post-card { max-width: none; margin-left: 0; margin-right: 0; }
        .detail-back { display: inline-flex; align-items: center; gap: 8px; color: var(--text-secondary); font-size: 0.92em; cursor: pointer; transition: all 0.25s ease; background: none; border: none; font-family: inherit; padding: 8px 14px; border-radius: 10px; margin-bottom: 4px; }
        .detail-back:hover { color: var(--accent); background: rgba(124,111,247,0.08); }

        /* === 帖子卡片 === */
        .post-card { background: var(--bg-card); border-radius: var(--radius-xl); border: 1px solid var(--border); margin-bottom: 28px; overflow: hidden; transition: all 0.3s ease; padding: 0 24px; box-shadow: var(--shadow-sm); }
        .post-card:hover { border-color: var(--border-glow); box-shadow: var(--shadow-glow), var(--shadow-md); }
        .post-card-header { display: flex; justify-content: space-between; align-items: center; padding: 20px 0 14px; }
        .post-author { display: flex; align-items: center; gap: 12px; cursor: pointer; transition: all 0.2s; padding: 3px 8px; border-radius: 12px; margin-left: -10px; }
        .post-author:hover { background: rgba(124,111,247,0.08); }
        .post-avatar { width: 48px; height: 48px; border-radius: 50%; background: linear-gradient(135deg, var(--primary), var(--accent)); display: flex; align-items: center; justify-content: center; font-size: 0.75em; font-weight: 700; flex-direction: column; text-align: center; line-height: 1.2; padding: 2px; word-break: break-all; font-family: "PingFang SC","Microsoft YaHei",sans-serif; box-shadow: 0 3px 12px rgba(124,111,247,0.2); }
        .post-author-info .name { font-weight: 700; font-size: 1em; color: var(--text-primary); }
        .post-author-info .meta { color: var(--text-muted); font-size: 0.82em; margin-top: 2px; }
        .post-status { padding: 3px 10px; border-radius: 20px; font-size: 0.7em; font-weight: 600; }
        .post-status.replied { background: rgba(94,158,255,0.12); color: var(--info); }
        .post-status.resolved { background: rgba(160,160,190,0.1); color: rgba(190,190,210,0.85); cursor: pointer; }
        .post-status.pending { background: rgba(255,190,77,0.12); color: var(--warning); }
.post-status.live-pending { background: rgba(255,107,107,0.12); color: var(--danger); cursor: pointer; }
        .post-title { padding: 0 0px 10px; font-size: 1.15em; font-weight: 700; line-height: 1.5; }
        .post-images { padding: 0 0px 12px; display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 8px; }
        .post-images img { width: 100%; max-height: 500px; object-fit: contain; border-radius: 10px; cursor: pointer; transition: transform 0.3s; background: var(--bg-dark); }
        .post-images img:hover { transform: scale(1.03); }
        .post-images > div:hover .set-cover-btn { opacity: 1 !important; }
        .set-cover-btn:hover { transform: scale(1.05); }
        .post-body { padding: 0 0 14px; color: var(--text-secondary); line-height: 1.75; font-size: 0.93em; }
        .post-body .tag { display: inline-block; padding: 3px 10px; border-radius: 6px; font-size: 0.7em; margin-right: 6px; margin-bottom: 4px; font-weight: 500; }
        .tag-progress { background: rgba(124,111,247,0.15); color: var(--accent); }
        .tag-class { background: rgba(124,111,247,0.15); color: var(--primary-light); }
        .tag-tool { background: rgba(251,107,157,0.12); color: var(--accent2); }

        /* === 盖楼回复 === */
        .reply-thread { border-top: none; margin-top: 6px; }
        .reply-count { background: rgba(124,111,247,0.15); color: var(--primary-light); padding: 3px 12px; border-radius: 12px; font-size: 0.7em; font-weight: 700; }
        .reply-floor { display: flex; gap: 10px; padding: 12px 14px; border-bottom: none; align-items: flex-start; justify-content: flex-start; border-radius: 10px; transition: background 0.2s ease, transform 0.2s ease; margin: 1px 0; }
        .reply-floor:nth-child(odd) { background: transparent; }
        .reply-floor:nth-child(even) { background: rgba(124,111,247,0.03); }
        .reply-floor:hover { background: rgba(124,111,247,0.05); }
        .reply-avatar { width: 40px; min-width: 40px; max-width: 40px; height: 40px; border-radius: 50%; flex-shrink: 0; display: flex; align-items: center; justify-content: center; font-size: 0.65em; font-weight: 700; overflow: hidden; box-sizing: border-box; text-align: center; line-height: 1.2; font-family: "PingFang SC","Microsoft YaHei",sans-serif; flex-direction: column; padding: 2px; word-break: break-all; }
        .reply-avatar.teacher-avatar { background: linear-gradient(135deg, var(--accent2), var(--primary)); color: #fff; box-shadow: 0 2px 8px rgba(251,107,157,0.2); }
        .reply-avatar.student-avatar { background: linear-gradient(135deg, var(--accent), var(--primary)); color: #fff; box-shadow: 0 2px 8px rgba(0,212,204,0.2); }
        .reply-content { flex: 1; min-width: 0; text-align: left; }
        .reply-meta { display: flex; align-items: center; gap: 4px; margin-bottom: 4px; flex-wrap: wrap; }
        .reply-name { font-weight: 700; font-size: 0.92em; transition: color 0.2s; }
        .reply-name.is-teacher { color: var(--text-primary); }
        .reply-name.is-student { color: var(--text-primary); }
        .reply-name[style*="cursor"] { border-radius: 4px; }
        .reply-name[style*="cursor"]:hover { color: var(--primary); text-decoration: underline; }
        .reply-avatar[style*="cursor"] { transition: transform 0.2s, box-shadow 0.2s; }
        .reply-avatar[style*="cursor"]:hover { transform: scale(1.1); box-shadow: 0 0 8px rgba(108,92,231,0.4); }
        .reply-floor-num { display: none; }
        .reply-time { color: var(--text-muted); font-size: 0.8em; }
        .reply-role-badge { padding: 2px 8px; border-radius: 6px; font-size: 0.7em; font-weight: 700; }
        .badge-teacher { background: rgba(251,107,157,0.12); color: var(--accent2); }
        .badge-student { background: rgba(124,111,247,0.12); color: var(--accent); }
        .badge-user { background: rgba(160,160,190,0.1); color: #aaa; }
        .reply-text { color: var(--text-secondary); line-height: 1.75; font-size: 0.92em; text-align: left; }
        .reply-text a { color: #74B9FF; text-decoration: underline; }
        .reply-text a:hover { color: #a0d2ff; }
        .reply-text .highlight { color: var(--text-secondary); font-weight: normal; }
        .reply-admin-actions { display: flex; gap: 6px; align-items: center; margin-top: 8px; }
        .reply-admin-btn { background: rgba(124,111,247,0.06); color: var(--text-muted); border: 1px solid transparent; padding: 3px 10px; border-radius: 6px; font-size: 0.72em; cursor: pointer; font-weight: 600; transition: all 0.2s ease; display: inline-flex; align-items: center; gap: 4px; user-select: none; }
        .reply-admin-btn:hover { background: rgba(124,111,247,0.14); color: var(--primary); border-color: rgba(124,111,247,0.25); transform: translateY(-1px); }
        .reply-admin-btn:active { transform: translateY(0) scale(0.97); }
        .reply-admin-btn-danger:hover { background: rgba(239,68,68,0.14); color: var(--danger); border-color: var(--danger); }
        .reply-children { margin-left: 40px; padding-left: 0; border-left: none; }
        .reply-children .reply-floor { padding: 8px 8px; gap: 8px; border-bottom: none; background: transparent !important; }
        .reply-children .reply-avatar { width: 28px; min-width: 28px; max-width: 28px; height: 28px; font-size: 0.55em; line-height: 1.1; padding: 1px; }
        .reply-children .reply-name { font-size: 0.85em; }
        .reply-children .reply-text { font-size: 0.88em; }
        .reply-children .reply-floor-num { display: none; }
        .reply-mention { color: var(--accent); font-weight: 600; font-size: 0.88em; cursor: pointer; }
        .reply-mention:hover { text-decoration: underline; }
        .reply-edit-area { width: 100%; padding: 10px; background: var(--bg-dark); border: 1.5px solid var(--primary); border-radius: 6px; color: var(--text-primary); font-size: 0.9em; line-height: 1.6; min-height: 80px; resize: vertical; outline: none; }
        .reply-edit-btns { display: flex; gap: 6px; margin-top: 6px; }
        .reply-images { display: flex; gap: 8px; margin-top: 8px; flex-wrap: wrap; }
        .reply-images img { width: 170px; height: auto; border-radius: 6px; border: 1px solid var(--border); cursor: pointer; transition: transform 0.2s; }
        .reply-images img:hover { transform: scale(1.05); }
        .reply-status-tag { display: inline-block; margin-top: 8px; padding: 3px 12px; border-radius: 6px; font-size: 0.76em; font-weight: 600; }
        .reply-status-tag.resolved { background: rgba(0,214,143,0.12); color: var(--success); }
        .reply-status-tag.pending { background: rgba(255,190,77,0.12); color: var(--warning); }
        .reply-status-tag.needmore { background: rgba(255,107,107,0.12); color: var(--danger); }

        /* === 回复输入框 === */
        .reply-composer { display: none; border-top: 2px dashed rgba(108,92,231,0.15); background: rgba(108,92,231,0.02); border-radius: 0 0 var(--radius-lg) var(--radius-lg); }
        .reply-composer.show { display: block; }
        .composer-inner { padding: 18px 0; }
        .composer-header { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; flex-wrap: wrap; }
        .composer-avatar { width: 36px; height: 36px; border-radius: 50%; background: linear-gradient(135deg, var(--accent2), var(--primary)); display: flex; align-items: center; justify-content: center; font-size: 0.65em; font-weight: 700; color: #fff; flex-direction: column; text-align: center; line-height: 1.2; padding: 2px; word-break: break-all; font-family: "PingFang SC","Microsoft YaHei",sans-serif; box-shadow: 0 2px 8px rgba(251,107,157,0.15); }
        .composer-header select { background: var(--bg-dark); border: 1.5px solid var(--border); border-radius: 6px; padding: 6px 12px; color: var(--text-primary); font-size: 0.85em; cursor: pointer; transition: border-color 0.2s; }
        .composer-header select:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(108,92,231,0.08); }
        .composer-textarea { width: 100%; min-height: 90px; background: var(--bg-dark); border: 1.5px solid var(--border); border-radius: 10px; padding: 12px 14px; color: var(--text-primary); font-size: 0.92em; font-family: inherit; resize: vertical; line-height: 1.6; transition: border-color 0.2s, box-shadow 0.2s; }
        .composer-textarea:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(108,92,231,0.08); }
        .emoji-picker-wrap { position: relative; display: inline-block; }
        .emoji-btn { background: var(--bg-dark); border: 1.5px solid var(--border); border-radius: 6px; padding: 3px 10px; cursor: pointer; font-size: 1.1em; color: var(--text-muted); transition: all 0.2s; }
        .emoji-btn:hover { background: rgba(124,111,247,0.12); color: var(--text-primary); border-color: var(--primary); }
        .emoji-panel { display: none; position: absolute; bottom: 38px; left: 0; background: var(--bg-card); border: 1px solid var(--border); border-radius: 12px; padding: 10px; width: 320px; max-height: 220px; overflow-y: auto; z-index: 1000; box-shadow: var(--shadow-lg); }
        .emoji-panel.show { display: block; }
        .emoji-panel span { display: inline-block; width: 36px; height: 36px; text-align: center; line-height: 36px; font-size: 1.3em; cursor: pointer; border-radius: 6px; transition: background 0.15s, transform 0.15s; }
        .emoji-panel span:hover { background: rgba(124,111,247,0.15); transform: scale(1.15); }
        .emoji-panel::-webkit-scrollbar { width: 4px; }
        .emoji-panel::-webkit-scrollbar-thumb { background: var(--border); border-radius: 2px; }
        .composer-toolbar { display: flex; justify-content: space-between; align-items: center; margin-top: 10px; gap: 8px; flex-wrap: wrap; }
        .image-upload-area { border: 2px dashed var(--border); border-radius: 10px; padding: 14px; text-align: center; color: var(--text-muted); cursor: pointer; transition: all 0.3s ease; position: relative; margin-top: 10px; font-size: 0.9em; }
        .image-upload-area:hover { border-color: var(--accent); color: var(--accent); background: rgba(0,212,204,0.03); }
        .image-upload-area.paste-active { border-color: var(--accent); background: rgba(108,92,231,0.05); animation: pastePulse 0.6s ease; }
        @keyframes pastePulse { 0% { box-shadow: 0 0 0 0 rgba(108,92,231,0.4); } 50% { box-shadow: 0 0 0 8px rgba(108,92,231,0); } 100% { box-shadow: none; } }
        .image-upload-area input[type="file"] { display: none; }
        .paste-hint { display: flex; align-items: center; justify-content: center; gap: 5px; margin-top: 6px; padding: 4px 8px; background: rgba(108,92,231,0.1); border-radius: 6px; color: var(--accent); font-size: 0.7em; font-weight: 600; }
        .paste-hint kbd { display: inline-block; padding: 1px 5px; background: rgba(108,92,231,0.2); border: 1px solid rgba(108,92,231,0.4); border-radius: 4px; font-family: inherit; font-size: 0.88em; }
        .uploaded-images { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 8px; }
        .img-preview { position: relative; display: inline-block; }
        .img-preview img { width: 75px; height: 55px; object-fit: cover; border-radius: 6px; border: 1px solid var(--border); }
        .img-preview .remove-img { position: absolute; top: -4px; right: -4px; width: 16px; height: 16px; border-radius: 50%; background: var(--danger); color: #fff; border: none; font-size: 0.65em; cursor: pointer; display: flex; align-items: center; justify-content: center; }
        .post-actions { display: flex; gap: 20px; padding: 12px 0; border-top: 1px solid var(--border); }
        .post-action-btn { background: none; border: none; color: var(--text-muted); cursor: pointer; font-size: 0.85em; display: inline-flex; align-items: center; gap: 5px; transition: all 0.2s ease; padding: 4px 10px; border-radius: 6px; font-weight: 500; user-select: none; }
        .post-action-btn:hover { color: var(--accent); background: rgba(45,212,191,0.06); transform: translateY(-1px); }
        .post-action-btn:active { transform: translateY(0) scale(0.97); }
        .admin-actions { display: none; gap: 8px; padding: 12px 0; border-top: 1px dashed rgba(108,92,231,0.15); background: rgba(108,92,231,0.02); border-radius: 0 0 var(--radius-lg) var(--radius-lg); }
        .admin-actions.show { display: flex; }
        .student-reply-actions { display: none; gap: 8px; padding: 12px 0; border-top: 1px dashed rgba(108,92,231,0.15); background: rgba(108,92,231,0.02); border-radius: 0 0 var(--radius-lg) var(--radius-lg); }
        .student-reply-actions.show { display: flex; }

        /* === 设置封面选择器 === */
        .cover-picker-overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.75); z-index: 600; justify-content: center; align-items: center; }
        .cover-picker-overlay.show { display: flex; }
        .cover-picker { background: var(--bg-card); border-radius: var(--radius-xl); padding: 24px; max-width: min(680px, 95vw); width: 92%; border: 1px solid var(--border); animation: fadeInUp 0.3s ease; max-height: 85vh; overflow-y: auto; box-shadow: var(--shadow-lg); }
        .cover-picker h3 { text-align: center; margin-bottom: 16px; font-size: 1.1em; }
        .cover-picker h3 .pick-hint { display: block; color: var(--text-muted); font-size: 0.7em; font-weight: 400; margin-top: 4px; }
        .cover-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 12px; }
        .cover-option { position: relative; border-radius: 12px; overflow: hidden; border: 3px solid transparent; cursor: pointer; transition: all 0.3s; }
        .cover-option:hover { border-color: rgba(108,92,231,0.5); transform: translateY(-2px); }
        .cover-option.selected { border-color: var(--accent); box-shadow: 0 0 16px rgba(108,92,231,0.3); }
        .cover-option img { width: 100%; height: 120px; object-fit: cover; display: block; }
        .cover-option .cover-check { position: absolute; top: 8px; right: 8px; width: 28px; height: 28px; border-radius: 50%; background: var(--accent); color: #fff; display: none; align-items: center; justify-content: center; font-size: 0.9em; font-weight: 700; }
        .cover-option.selected .cover-check { display: flex; }
        .cover-option .cover-floor-label { position: absolute; bottom: 0; left: 0; right: 0; padding: 3px 8px; background: rgba(0,0,0,0.7); color: var(--text-secondary); font-size: 0.73em; text-align: center; }
        .cover-picker-btns { display: flex; justify-content: center; gap: 10px; margin-top: 18px; }

        /* === 灯箱 === */
        .lightbox { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.9); z-index: 1000; overflow: auto; cursor: pointer; }
        .lightbox.active { display: block; }
        .lightbox img { position: absolute; top: 50%; left: 50%; transform: translate(-50%,-50%); border-radius: 10px; transition: width 0.2s ease, height 0.2s ease, transform 0.2s ease; transform-origin: center center; max-width: none; max-height: none; }
        .lightbox .zoom-hint { position: fixed; bottom: 18px; left: 50%; transform: translateX(-50%); color: rgba(255,255,255,0.6); font-size: 0.82em; pointer-events: none; z-index: 1001; }
        .lightbox-counter { position: fixed; top: 16px; left: 50%; transform: translateX(-50%); z-index: 1002; color: rgba(255,255,255,0.8); font-size: 0.88em; background: rgba(0,0,0,0.5); padding: 4px 14px; border-radius: 14px; }
        .lightbox-click-zone-left { position: fixed; top: 0; left: 0; width: 30%; height: 100%; z-index: 1001; cursor: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32"><text x="0" y="26" font-size="28" fill="white">◀</text></svg>'), pointer; }
        .lightbox-click-zone-right { position: fixed; top: 0; right: 0; width: 30%; height: 100%; z-index: 1001; cursor: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32"><text x="8" y="26" font-size="28" fill="white">▶</text></svg>'), pointer; }

        /* === 弹窗通用 === */
        .modal-overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.7); z-index: 500; justify-content: center; align-items: center; }
        .modal-overlay.show { display: flex; }
        .modal { background: var(--bg-card); border-radius: var(--radius-xl); padding: 28px; max-width: 460px; width: 92%; border: 1px solid var(--border); animation: fadeInUp 0.3s ease; max-height: 90vh; overflow-y: auto; box-shadow: var(--shadow-lg); }
        .modal-content { background: var(--bg-card); border-radius: var(--radius-xl); padding: 28px; width: 92%; border: 1px solid var(--border); animation: fadeInUp 0.3s ease; max-height: 90vh; overflow-y: auto; box-shadow: var(--shadow-lg); }
        .modal h3 { font-size: 1.2em; margin-bottom: 16px; text-align: center; }
        .modal .close-btn { float: right; background: none; border: none; color: var(--text-muted); font-size: 1.4em; cursor: pointer; }
        .form-group { margin-bottom: 14px; }
        .form-group label { display: block; color: var(--text-secondary); font-size: 0.85em; margin-bottom: 5px; font-weight: 600; }
        .form-group input, .form-group textarea, .form-group select { width: 100%; background: var(--bg-dark); border: 1.5px solid var(--border); border-radius: 10px; padding: 10px 14px; color: var(--text-primary); font-size: 0.92em; font-family: inherit; transition: border-color 0.2s, box-shadow 0.2s; }
        .form-group input:focus, .form-group textarea:focus, .form-group select:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(108,92,231,0.08); }
        .form-group select { cursor: pointer; }
        .form-group select option { background: #fff; color: #333; }
        select option { background: #fff; color: #333; }
        select { color: var(--text-primary); }

        /* === 身份选择 === */
        .role-select { display: flex; gap: 12px; margin-bottom: 16px; }
        .role-card { flex: 1; padding: 20px 14px; border-radius: 14px; border: 2px solid var(--border); text-align: center; cursor: pointer; transition: all 0.3s ease; }
        .role-card:hover { border-color: var(--primary); transform: translateY(-2px); box-shadow: 0 4px 16px rgba(124,111,247,0.1); }
        .role-card.selected { border-color: var(--primary); background: rgba(124,111,247,0.12); box-shadow: 0 0 20px rgba(124,111,247,0.15); }
        .role-card .role-icon { font-size: 2.2em; margin-bottom: 6px; }
        .role-card .role-name { font-weight: 600; font-size: 0.92em; }
        .role-card .role-desc { color: var(--text-muted); font-size: 0.7em; margin-top: 3px; }

        /* === QQ扫码登录 === */
        .qr-login-section { text-align: center; padding: 10px 0; }
        .qr-box { position: relative; width: 200px; height: 200px; margin: 0 auto 16px; border-radius: 16px; overflow: hidden; border: 2px solid var(--border); background: #fff; }
        .qr-box canvas { width: 100%; height: 100%; }
        .qr-scan-line { position: absolute; top: 0; left: 10px; right: 10px; height: 3px; background: linear-gradient(90deg, transparent, var(--accent), transparent); animation: qrScan 2s ease-in-out infinite; border-radius: 2px; }
        @keyframes qrScan { 0% { top: 10px; } 50% { top: calc(100% - 14px); } 100% { top: 10px; } }
        .qr-hint { color: var(--text-secondary); font-size: 0.88em; margin-bottom: 12px; }
        .qr-hint strong { color: var(--accent); }
        .qr-status { display: flex; align-items: center; justify-content: center; gap: 8px; padding: 10px; border-radius: 10px; font-size: 0.88em; margin-top: 8px; }
        .qr-status.scanning { background: rgba(108,92,231,0.1); color: var(--accent); }
        .qr-status.success { background: rgba(0,184,148,0.1); color: var(--success); }
        .qr-status .spinner { width: 16px; height: 16px; border: 2px solid rgba(108,92,231,0.3); border-top-color: var(--accent); border-radius: 50%; animation: spin 0.8s linear infinite; }
        @keyframes spin { to { transform: rotate(360deg); } }
        .login-step { display: none; }
        .login-step.active { display: block; }
        .qq-avatar-lg { width: 64px; height: 64px; border-radius: 50%; background: linear-gradient(135deg, #12B7F5, #6C5CE7); display: flex; align-items: center; justify-content: center; font-size: 1.8em; margin: 0 auto 12px; box-shadow: 0 4px 20px rgba(108,92,231,0.3); }
        .bound-qq-info { display: flex; align-items: center; gap: 12px; padding: 12px 16px; background: var(--bg-dark); border-radius: 12px; margin-bottom: 12px; }
        .bound-qq-info .qq-avatar-sm { width: 42px; height: 42px; border-radius: 50%; background: linear-gradient(135deg, #12B7F5, #6C5CE7); display: flex; align-items: center; justify-content: center; font-size: 1.2em; }
        .bound-qq-info .qq-detail { flex: 1; }
        .bound-qq-info .qq-detail .qq-nick { font-weight: 600; font-size: 0.95em; }
        .bound-qq-info .qq-detail .qq-num { color: var(--text-muted); font-size: 0.82em; }
        .quick-login-list { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; margin: 12px 0; }
        .quick-login-item { display: flex; flex-direction: column; align-items: center; gap: 4px; cursor: pointer; padding: 12px 16px; border-radius: 14px; border: 2px solid var(--border); transition: all 0.3s ease; min-width: 72px; }
        .quick-login-item:hover { border-color: var(--primary); background: rgba(124,111,247,0.08); transform: translateY(-3px); box-shadow: 0 4px 16px rgba(124,111,247,0.15); }
        .quick-login-item .ql-avatar { width: 40px; height: 40px; border-radius: 50%; background: linear-gradient(135deg, #12B7F5, #6C5CE7); display: flex; align-items: center; justify-content: center; font-size: 1.1em; }
        .quick-login-item .ql-name { font-size: 0.72em; color: var(--text-secondary); font-weight: 600; }
        /* 头像通知徽标 */
        .avatar-notif-badge {
            display: none;
            position: absolute;
            top: -6px;
            right: -8px;
            min-width: 20px;
            height: 20px;
            line-height: 20px;
            padding: 0 5px;
            border-radius: 10px;
            background: #EF4444;
            color: #fff;
            font-size: 0.65em;
            font-weight: 700;
            text-align: center;
            z-index: 10;
            box-shadow: 0 2px 6px rgba(239,68,68,0.5);
            cursor: pointer;
            animation: badgePopIn 0.3s ease;
        }
        .avatar-notif-badge.show { display: block; }
        @keyframes badgePopIn { 0% { transform: scale(0); } 70% { transform: scale(1.2); } 100% { transform: scale(1); } }
        .user-info { position: relative; }

        /* === 班级二级选择 === */
        .class-selectors { display: flex; gap: 10px; }
        .class-selectors .form-group { flex: 1; }

        /* === 提交作业弹窗 === */
        .submit-form .class-selectors { margin-bottom: 12px; }
        .submit-form .form-group textarea { min-height: 120px; }

        /* === 底部 === */
        .footer { text-align: center; padding: 14px 20px; color: var(--text-muted); font-size: 0.78em; border-top: 1px solid var(--border); background: var(--bg-dark); }
        .footer a { color: var(--primary); text-decoration: none; opacity: 0.8; transition: opacity 0.2s; }
        .footer a:hover { opacity: 1; }

        /* === 通知 === */
        .notification-banner { display: none; position: fixed; top: 72px; right: 20px; background: linear-gradient(135deg, var(--success), #00b87a); color: #fff; padding: 12px 20px; border-radius: 14px; font-weight: 600; z-index: 200; animation: slideIn 0.3s ease; box-shadow: 0 6px 24px rgba(0,214,143,0.35); font-size: 0.9em; }
        .notification-banner.show { display: flex; align-items: center; gap: 6px; }
        @keyframes slideIn { from { opacity: 0; transform: translateX(50px); } to { opacity: 1; transform: translateX(0); } }

        @keyframes fadeInUp { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
        .thumb-card:nth-child(2) { animation-delay: 0.05s; }
        .thumb-card:nth-child(3) { animation-delay: 0.1s; }

        .hw-type-card { transition: all 0.3s; position: relative; }
        .hw-type-card:hover { border-color: var(--primary); color: var(--primary); }
        .hw-type-card.selected { border: 2px solid #3b8cff; background: rgba(59,140,255,0.1); color: #3b8cff; box-shadow: none; }
        .hw-type-card.selected::after { content: '\2713'; position: absolute; top: -1px; right: -1px; width: 22px; height: 22px; background: #3b8cff; color: #fff; border-radius: 0 12px 0 8px; display: flex; align-items: center; justify-content: center; font-size: 12px; font-weight: 700; line-height: 1; }
        .hw-type-card.selected div { color: rgba(59,140,255,0.7); }
        #homeworkTypeGroup:not(:has(.selected)) .hw-type-card { opacity: 1; }
        #homeworkTypeGroup:has(.selected) .hw-type-card:not(.selected) { opacity: 0.35; border-color: var(--border); color: var(--text-muted); filter: grayscale(0.6); }
        #homeworkTypeGroup:has(.selected) .hw-type-card:not(.selected) div { color: var(--text-muted); }
        .tag-hw-type { background: rgba(253,203,110,0.15); color: var(--warning); font-size:0.78em; padding:3px 10px; border-radius:8px; margin-right:6px; margin-bottom:4px; display:inline-block; }

/* === 个人后台弹窗 === */
.profile-overlay { display: none; position: fixed; inset: 0; background: rgba(0,0,0,0.7); z-index: 600; justify-content: center; align-items: flex-start; padding-top: 60px; overflow-y: auto; }
.profile-overlay.show { display: flex; }
.profile-panel { background: var(--bg-card); border-radius: 18px; border: 1px solid var(--border); width: 95%; max-width: 480px; margin-bottom: 40px; overflow: hidden; animation: slideUp 0.3s ease; }
@keyframes slideUp { from { opacity: 0; transform: translateY(30px); } to { opacity: 1; transform: translateY(0); } }
.profile-header { background: linear-gradient(135deg, rgba(108,92,231,0.10), rgba(108,92,231,0.04)); padding: 24px 20px 18px; text-align: center; position: relative; }
.profile-header .close-btn { position: absolute; top: 14px; right: 16px; background: rgba(0,0,0,0.06); border: none; color: var(--text-secondary); width: 30px; height: 30px; border-radius: 50%; cursor: pointer; font-size: 1.1em; display: flex; align-items: center; justify-content: center; }
.profile-header .close-btn:hover { background: rgba(0,0,0,0.12); color: var(--text-primary); }
.profile-big-avatar { width: 72px; height: 72px; border-radius: 50%; background: linear-gradient(135deg, var(--primary), #5A4BD1); display: flex; align-items: center; justify-content: center; margin: 0 auto 8px; font-size: 2em; border: 3px solid rgba(255,255,255,0.8); overflow: hidden; position: relative; cursor: pointer; }
.profile-big-avatar img { width: 100%; height: 100%; object-fit: cover; }
.profile-big-avatar:hover::after { content: '📷'; position: absolute; inset: 0; background: rgba(0,0,0,0.5); display: flex; align-items: center; justify-content: center; font-size: 1.4em; }
.profile-big-name { font-size: 1.15em; font-weight: 700; color: var(--text-primary); cursor: pointer; text-align: center; }
.profile-big-name:hover { color: var(--primary); }
.profile-big-role { font-size: 0.8em; color: var(--text-muted); margin-top: 3px; }
.profile-body { padding: 16px 20px 20px; }
.profile-section { margin-bottom: 16px; }
.profile-section-title { font-size: 0.82em; font-weight: 700; color: var(--text-muted); letter-spacing: 0.5px; margin-bottom: 10px; }
.profile-field { display: flex; align-items: center; justify-content: space-between; padding: 10px 14px; background: rgba(0,0,0,0.2); border-radius: 10px; margin-bottom: 6px; }
.profile-field-label { font-size: 0.85em; color: var(--text-secondary); min-width: 60px; }
.profile-field-value { font-size: 0.85em; color: var(--text-primary); font-weight: 600; }
.profile-input { width: 100%; padding: 8px 12px; background: var(--bg-dark); border: 1px solid var(--border); border-radius: 6px; color: var(--text-primary); font-size: 0.88em; outline: none; }
.profile-input:focus { border-color: var(--primary); }
.profile-select { width: 100%; padding: 8px 12px; background: var(--bg-dark); border: 1px solid var(--border); border-radius: 6px; color: var(--text-primary); font-size: 0.88em; outline: none; appearance: none; cursor: pointer; }
.profile-select option { background: #fff; color: var(--text-primary); }
.profile-footer { padding: 16px 20px 20px; display: flex; gap: 12px; }
.profile-save-all { flex:1; padding: 12px; background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: #fff; border: none; border-radius: 10px; font-size: 0.95em; font-weight: 700; cursor: pointer; transition: all 0.2s; }
.profile-save-all:hover { transform: translateY(-1px); box-shadow: 0 4px 16px rgba(108,92,231,0.4); }
.profile-logout { flex:1; padding: 12px; background: rgba(232,120,74,0.12); color: var(--danger); border: 1px solid rgba(232,120,74,0.3); border-radius: 10px; font-size: 0.95em; font-weight: 700; cursor: pointer; transition: all 0.2s; }
.profile-logout:hover { background: rgba(232,120,74,0.25); }
/* 我的作品 - 卡片形式 */
.my-work-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.my-work-card { background: var(--bg-card); border-radius: 12px; overflow: hidden; cursor: pointer; transition: all 0.25s; border: 1px solid var(--border); }
.my-work-card:hover { transform: translateY(-3px); box-shadow: 0 6px 20px rgba(0,0,0,0.08); border-color: var(--primary); }
.my-work-card-img { width: 100%; height: 100px; background: var(--bg-dark); overflow: hidden; position: relative; }
.my-work-card-img img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.3s; }
.my-work-card:hover .my-work-card-img img { transform: scale(1.05); }
.my-work-card-badge { position: absolute; top: 6px; right: 6px; padding: 2px 8px; border-radius: 6px; font-size: 0.68em; font-weight: 600; backdrop-filter: blur(6px); }
.my-work-card-badge.feedback { background: rgba(116,185,255,0.85); color: #fff; }
.my-work-card-badge.resolved { background: rgba(0,184,148,0.85); color: #fff; }
.my-work-card-badge.pending { background: rgba(253,203,110,0.85); color: #333; }
.my-work-card-body { padding: 8px 10px 10px; }
.my-work-card-title { font-size: 0.82em; font-weight: 600; color: var(--text-primary); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.my-work-card-meta { font-size: 0.7em; color: var(--text-muted); margin-top: 3px; }
/* 个人后台缩略图行（3列） */
.profile-thumb-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; }
.profile-thumb-card { background: var(--bg-card); border-radius: 10px; overflow: hidden; cursor: pointer; border: 1px solid var(--border); transition: all 0.2s; }
.profile-thumb-card:hover { border-color: var(--primary); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.profile-thumb-card-img { width: 100%; height: 72px; background: var(--bg-dark); overflow: hidden; position: relative; }
.profile-thumb-card-img img { width: 100%; height: 100%; object-fit: cover; }
.profile-thumb-card-title { padding: 4px 6px 6px; font-size: 0.72em; color: var(--text-secondary); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.profile-thumb-empty { font-size: 0.8em; color: var(--text-muted); padding: 8px 0; }
.my-work-empty { text-align: center; padding: 20px 0; color: var(--text-muted); font-size: 0.85em; grid-column: 1 / -1; }
.user-info { cursor: pointer; }
.user-info:hover { opacity: 0.8; }

/* === Tab切换栏 === */
.section-tabs { display: flex; gap: 0; background: var(--bg-card); border-radius: 14px; padding: 5px; margin: 0 auto 22px; border: 1px solid var(--border); max-width: 500px; box-shadow: var(--shadow-sm); }
.section-tab { flex: 1; padding: 12px; text-align: center; border-radius: 10px; cursor: pointer; font-weight: 600; font-size: 0.92em; color: var(--text-muted); transition: all 0.3s ease; user-select: none; }
.section-tab:hover { color: var(--text-primary); background: rgba(255,255,255,0.03); }
.section-tab.active { background: linear-gradient(135deg, var(--primary), var(--primary-dark)); color: #fff; box-shadow: 0 4px 16px rgba(124,111,247,0.35); transform: scale(1.02); }


/* === 用户管理面板 === */
.user-manage-panel { background: var(--bg-card); border: 1px solid var(--border); border-radius: 12px; padding: 20px; margin-bottom: 16px; }
.user-manage-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 16px; }
.user-manage-header h3 { margin: 0; font-size: 1.1em; }
.user-manage-tabs { display: flex; gap: 8px; margin-bottom: 16px; }
.um-tab { padding: 6px 16px; border-radius: 20px; font-size: 0.85em; cursor: pointer; border: 1px solid var(--border); color: var(--text-secondary); transition: all 0.2s; }
.um-tab:hover { border-color: var(--primary); color: var(--primary); }

.um-menu-item { padding: 14px 18px; cursor: pointer; font-size: 0.95em; color: var(--text-secondary); border-left: 3px solid transparent; transition: all 0.2s; }
.um-menu-item:hover { background: rgba(108,92,231,0.08); color: var(--text-primary); }
.um-menu-item.active { background: rgba(108,92,231,0.15); color: var(--accent); border-left-color: var(--accent); font-weight: 600; }
/* 自定义下拉框 */
.custom-select-options .custom-option:hover { background: rgba(108,92,231,0.12); color: var(--accent); }
.custom-select-options .custom-option:first-child:hover { background: rgba(108,92,231,0.08); color: var(--text-muted); }
        .um-panel { background: var(--bg-card); border: 1px solid var(--border); border-radius: 14px; padding: 20px; }
.um-tab.active { background: var(--primary); color: #fff; border-color: var(--primary); }

/* 开关切换 */
.toggle-switch { position: relative; display: inline-block; width: 44px; height: 24px; cursor: pointer; }
.toggle-switch input { opacity: 0; width: 0; height: 0; }
.toggle-slider { position: absolute; inset: 0; background: #444; border-radius: 12px; transition: all 0.3s; }
.toggle-slider::before { content: ''; position: absolute; height: 18px; width: 18px; left: 3px; bottom: 3px; background: #fff; border-radius: 50%; transition: all 0.3s; }
.toggle-switch input:checked + .toggle-slider { background: var(--success); }
.toggle-switch input:checked + .toggle-slider::before { transform: translateX(20px); }
.user-manage-list { display: flex; flex-direction: column; gap: 8px; }
.um-user-card { display: flex; align-items: center; gap: 12px; padding: 10px 14px; background: var(--bg-main); border: 1px solid var(--border); border-radius: 10px; cursor: pointer; transition: all 0.2s; }
.um-user-card:hover { border-color: var(--primary); background: rgba(108,92,231,0.05); }
.um-user-avatar { width: 36px; height: 36px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: 1.2em; background: var(--bg-card); border: 2px solid var(--border); }
.um-user-info { flex: 1; }
.um-user-name { font-weight: 600; font-size: 0.95em; }
.um-user-meta { font-size: 0.8em; color: var(--text-muted); }
.um-user-role { font-size: 0.7em; padding: 2px 8px; border-radius: 10px; font-weight: 600; }
.um-role-student { background: rgba(108,92,231,0.15); color: var(--primary); }
.um-role-teacher { background: rgba(46,213,115,0.15); color: var(--success); }
.um-role-pending { background: rgba(255,193,7,0.15); color: #ffc107; }
.um-role-user { background: rgba(150,150,150,0.15); color: #aaa; }
.um-empty { text-align: center; padding: 30px; color: var(--text-muted); font-size: 0.9em; }

/* 用户主页 */
#userPageView { padding-bottom: 40px; }
/* ========== 个人后台新布局 ========== */
#userPageView { z-index: 2147483646 !important; }
.upp-container { display: flex; height: 100%; overflow: hidden; }
.upp-sidebar {
    width: 180px; min-width: 180px; flex-shrink: 0;
    background: var(--bg-card);
    display: flex; flex-direction: column;
    border-right: 1px solid var(--border);
}
.upp-sidebar-profile {
    padding: 14px 16px 10px; flex-shrink: 0;
    border-bottom: 1px solid var(--border);
    display: flex; justify-content: center;
}
.upp-sidebar-menu {
    flex: 1; overflow-y: auto; padding: 12px 0 12px 20px;
    min-height: 0;
}
.upp-sidebar-avatar {
    width: 36px; height: 36px; border-radius: 50%;
    flex-shrink: 0;
    overflow: hidden; border: 1.5px solid var(--accent);
}
.upp-sidebar-avatar img { width: 100%; height: 100%; object-fit: cover; }
.upp-sidebar-name { font-size: 0.85em; font-weight: 600; color: var(--text-primary); }
.upp-sidebar-role { font-size: 0.7em; color: var(--accent); margin-top: 1px; }
.upp-sidebar-menu { flex: 1; padding: 12px 0 12px 20px; overflow-y: auto; }
.upp-menu-item {
    display: flex; align-items: center; gap: 10px;
    padding: 12px 16px; margin: 2px 0;
    border-radius: 6px; cursor: pointer;
    color: var(--text-secondary); font-size: 0.88em;
    transition: all 0.2s;
}
.upp-menu-item:hover { background: rgba(108,92,231,0.06); color: var(--text-primary); }
.upp-menu-item.active { background: var(--accent); color: #fff; font-weight: 600; }
.upp-menu-item .upp-menu-icon { flex-shrink: 0; display: flex; align-items: center; }
.upp-menu-item .upp-menu-badge {
    margin-left: 6px; font-size: 0.65em; font-weight: 700;
    background: rgba(232,120,74,0.85); color: #fff;
    min-width: 16px; height: 16px; border-radius: 6px;
    display: flex; align-items: center; justify-content: center;
    padding: 0 6px;
}
.upp-main {
    flex: 1; display: flex; flex-direction: column;
    overflow: hidden; background: var(--bg-card);
}
.upp-main-header {
    padding: 14px 24px; flex-shrink: 0;
    border-bottom: 1px solid var(--border);
    display: flex; align-items: center; justify-content: space-between;
}
.upp-main-header h2 { margin: 0; font-size: 1.05em; color: var(--text-primary); }
.upp-main-header .upp-count { font-size: 0.85em; color: var(--text-muted); }
.upp-main-content {
    flex: 1; overflow-y: auto; padding: 20px 24px;
}
.upp-work-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 14px;
}
.upp-work-card {
    background: var(--bg-card); border-radius: 12px; overflow: hidden;
    border: 1px solid var(--border); cursor: pointer;
    transition: all 0.25s;
}
.upp-work-card:hover { transform: translateY(-3px); box-shadow: 0 6px 20px rgba(0,0,0,0.08); border-color: var(--primary); }
.upp-work-card-img {
    width: 100%; height: 160px; background: var(--bg-dark);
    overflow: hidden; position: relative;
}
.upp-work-card-img img { width: 100%; height: 100%; object-fit: cover; }
.upp-work-card-badge {
    position: absolute; top: 8px; right: 8px;
    padding: 3px 10px; border-radius: 10px;
    font-size: 0.7em; font-weight: 700;
}
.upp-work-card-badge.feedback { background: var(--success); color: #fff; }
.upp-work-card-badge.pending { background: var(--danger); color: #fff; }
.upp-work-card-body { padding: 10px 12px; }
.upp-work-card-title { font-size: 0.82em; font-weight: 600; color: var(--text-primary); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.upp-work-card-meta { font-size: 0.72em; color: var(--text-muted); margin-top: 4px; }
.upp-empty { text-align: center; padding: 60px 20px; color: var(--text-muted); }
.upp-empty-icon { font-size: 3em; margin-bottom: 12px; opacity: 0.5; }
/* 课程卡片网格 */
.upp-course-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 20px; }
.upp-course-card { border-radius: 14px; overflow: hidden; cursor: pointer; border: 1px solid var(--border); transition: all 0.3s; display: flex; flex-direction: column; }
.upp-course-card:hover { transform: translateY(-4px); box-shadow: 0 12px 40px rgba(0,0,0,0.5); border-color: var(--accent); }
/* 顶部图片区 */
.upp-course-card-top { height: 160px; position: relative; overflow: hidden; }
.upp-course-card-top-bg { position: absolute; inset: 0; background-size: cover; background-position: center; background-color: #2a2a2a; }
.upp-course-card-no-img .upp-course-card-top-bg { background: #2a2a2a; }
.upp-course-card-top-overlay { position: absolute; inset: 0; display: flex; align-items: flex-end; padding: 14px 16px; }
.upp-course-card-top-title { font-size: 1.4em; font-weight: 800; color: #FFD700; text-shadow: 0 1px 4px rgba(0,0,0,0.4); }
.upp-course-card-top-tag { position: absolute; top: 8px; right: 8px; padding: 3px 10px; border-radius: 4px; font-size: 0.72em; font-weight: 600; background: rgba(0,0,0,0.45); color: #FFD700; border: 1px solid rgba(255,215,0,0.25); white-space: nowrap; }
/* 底部信息区 - 深灰底色 */
.upp-course-card-bottom { background: #1e1e1e; padding: 14px 16px; display: flex; flex-direction: column; gap: 6px; }
.upp-course-card-class-row { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.upp-course-card-class-name { font-size: 0.95em; font-weight: 600; color: var(--text-primary); }
/* 状态标签：进行中(橙) / 已结课(灰) */
.upp-course-card-status { padding: 3px 12px; border-radius: 12px; font-size: 0.72em; font-weight: 600; }
.upp-course-card-status.live { background: #E17055; color: #fff; }
.upp-course-card-status.done { background: #6B7280; color: #fff; }
.upp-course-card-info-row { display: flex; align-items: center; justify-content: space-between; gap: 8px; margin-top: 4px; }
.upp-course-card-type { font-size: 0.8em; color: #888; }
.upp-course-card-teacher { font-size: 0.7em; color: #888; }

#userPageCard { position: relative; }
#userPageCard::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--accent), var(--accent2));
    border-radius: 16px 16px 0 0;
}
#userPagePosts .my-work-grid {
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
}
#userPagePosts .my-work-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.2s;
}
#userPagePosts .my-work-card:hover {
    border-color: var(--primary);
    box-shadow: 0 4px 20px rgba(108,92,231,0.15);
    transform: translateY(-2px);
}
#userPagePosts .my-work-card-img {
    width: 100%;
    height: 140px;
    overflow: hidden;
    position: relative;
}
#userPagePosts .my-work-card-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
#userPagePosts .my-work-card-badge {
    position: absolute;
    top: 8px;
    right: 8px;
    padding: 2px 8px;
    border-radius: 6px;
    font-size: 0.75em;
    font-weight: 700;
}
#userPagePosts .my-work-card-badge.feedback { background: rgba(0,184,148,0.2); color: var(--success); }
#userPagePosts .my-work-card-badge.pending { background: rgba(232,120,74,0.2); color: var(--danger); }
#userPagePosts .my-work-card-body { padding: 10px 12px; }
#userPagePosts .my-work-card-title {
    font-size: 0.85em;
    font-weight: 600;
    color: var(--text-primary);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* === 直播课模块样式 === */
.live-header { display: flex; align-items: center; justify-content: space-between; padding: 12px 24px 8px; gap: 12px; }
.live-add-btn { padding: 8px 16px; border-radius: 8px; border: 1px solid var(--accent); background: var(--accent); color: #fff; font-size: 0.85em; font-weight: 600; cursor: pointer; transition: all 0.2s; white-space: nowrap; }
.live-add-btn:hover { opacity: 0.9; transform: translateY(-1px); }

.live-group-header { display: flex; align-items: center; gap: 10px; padding: 16px 20px 8px; font-size: 1em; font-weight: 700; color: var(--text-primary); }
.live-group-header .live-count { font-size: 0.82em; font-weight: 400; color: var(--text-muted); }
.live-group-header .live-schedule { font-size: 0.82em; font-weight: 400; color: var(--text-muted); margin-left: auto; }

.live-grid { display: grid; grid-template-columns: repeat(auto-fill, 260px); gap: 30px; padding: 24px 0 36px; justify-content: center; /* 增加顶部内边距，让内容往上移 */ }
.live-card { width: 260px; background: var(--bg-card); border-radius: 10px; border: 1px solid var(--border); overflow: hidden; transition: all 0.25s cubic-bezier(0.4,0,0.2,1); position: relative; box-shadow: 0 1px 3px rgba(0,0,0,.06), 0 1px 2px rgba(0,0,0,.04); }
.live-card:hover { transform: translateY(-6px); box-shadow: 0 12px 28px rgba(0,0,0,.1), 0 0 0 1px rgba(99,102,241,.12); border-color: var(--border-glow); }
.live-card.suspended { opacity: 0.6; }

.live-card-image { width: 100%; height: 120px; overflow: hidden; position: relative; background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%); }
.live-card-image img { width: 100%; height: 100%; object-fit: cover; transition: transform 0.4s; }
.live-card:hover .live-card-image img { transform: scale(1.08); }
.live-card-overlay { position: absolute; inset: 0; display: flex; flex-direction: column; justify-content: space-between; padding: 10px 12px; background: linear-gradient(180deg, rgba(0,0,0,0.15) 0%, transparent 30%, transparent 60%, rgba(0,0,0,0.6) 100%); }
.live-card-overlay .live-card-class { font-size: 0.78em; font-weight: 600; color: #fff; text-shadow: 0 1px 3px rgba(0,0,0,0.6); }
.live-card-overlay .live-card-instructor { font-size: 0.72em; color: rgba(255,255,255,0.85); text-shadow: 0 1px 2px rgba(0,0,0,0.5); }
.live-card-overlay .live-card-session { align-self: flex-end; font-size: 1.4em; font-weight: 800; color: #fff; text-shadow: 0 2px 6px rgba(0,0,0,0.5); }

.live-card-body { padding: 6px 10px; }
.live-card-title { font-size: 0.75em; font-weight: 700; color: var(--text-primary); }
.live-card-info { display: flex; align-items: center; justify-content: space-between; font-size: 0.68em; }
.live-card-date { color: var(--accent); font-weight: 500; display: flex; align-items: center; gap: 4px; }
.live-card-time { color: var(--text-muted); }
.live-card-status { position: absolute; top: 8px; right: 8px; padding: 2px 8px; border-radius: 4px; font-size: 0.7em; font-weight: 600; z-index: 5; }
.live-card-status.normal { background: rgba(16,185,129,0.9); color: #fff; }
.live-card-status.suspended { background: rgba(239,68,68,0.9); color: #fff; }

.live-card-actions { display: flex; gap: 4px; }
.live-card-actions button { width: 20px; height: 20px; border-radius: 50%; border: 1px solid var(--border); background: var(--bg-card); color: var(--text-muted); font-size: 9px; cursor: pointer; display: flex; align-items: center; justify-content: center; transition: all 0.2s; }
.live-card-actions button:hover { border-color: var(--accent); color: var(--accent); }

/* 直播课表单弹窗 */
.live-form-overlay { position: fixed; top: 0; left: 0; right: 0; bottom: 0; background: rgba(0,0,0,0.55); z-index: 9999; display: flex; align-items: center; justify-content: center; padding: 20px; box-sizing: border-box; backdrop-filter: blur(2px); -webkit-backdrop-filter: blur(2px); }
.live-form { background: var(--bg-card); border-radius: 12px; padding: 24px 28px; width: 560px; max-width: 100%; max-height: 90vh; overflow-y: auto; box-shadow: 0 20px 60px rgba(0,0,0,0.4); border: 1px solid var(--border); position: relative; }
.live-form h3 { font-size: 1.2em; font-weight: 700; margin: 0 0 20px; padding-bottom: 12px; border-bottom: 1px solid var(--border); }
.live-form-field { margin-bottom: 14px; }
.live-form-field label { display: block; font-size: 0.85em; font-weight: 600; color: var(--text-muted); margin-bottom: 6px; }
.live-form-field input, .live-form-field textarea, .live-form-field select { width: 100%; padding: 10px 12px; border-radius: 8px; border: 1px solid var(--border); background: var(--bg-main); color: var(--text-primary); font-size: 0.9em; font-family: inherit; box-sizing: border-box; transition: border-color 0.2s; }
.live-form-field input:focus, .live-form-field textarea:focus, .live-form-field select:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(108,92,231,0.12); }
.live-form-field textarea { resize: vertical; min-height: 70px; }
.live-form-row { display: flex; gap: 14px; }
.live-form-row .live-form-field { flex: 1; }
.live-form-actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 20px; padding-top: 16px; border-top: 1px solid var(--border); }
.live-form-actions button { padding: 10px 24px; border-radius: 8px; font-size: 0.9em; font-weight: 600; cursor: pointer; transition: all 0.2s; border: none; }
.live-form-actions .btn-save { background: var(--accent); color: #fff; }
.live-form-actions .btn-save:hover { opacity: 0.9; transform: translateY(-1px); }
.live-form-actions .btn-cancel { background: transparent; color: var(--text-muted); border: 1px solid var(--border); }
.live-form-actions .btn-cancel:hover { border-color: var(--text-muted); color: var(--text-primary); }

.live-empty { text-align: center; padding: 60px 20px; color: var(--text-muted); }
.live-empty-icon { font-size: 3em; margin-bottom: 12px; }

@media (max-width: 768px) {
    .live-grid { grid-template-columns: 1fr !important; gap: 12px; padding: 4px 4px 36px; }
    .live-card { max-width: 100%; }
    .live-form { width: 100%; padding: 18px 16px; }
    .live-form-row { flex-direction: column; gap: 0; }
}

/* === 学员视图隐藏（纯CSS，仅视觉层，不触碰任何业务逻辑）=== */
body.is-student .reply-admin-actions { display: none !important; }
body.is-student .set-cover-btn { display: none !important; }
body.is-student .cover-picker-overlay { display: none !important; }


/* ═══════════ 学生互助模块样式 ═══════════ */

/* 筛选按钮 */
.help-filter-btn {
    padding: 6px 14px;
    border: 1px solid var(--border);
    border-radius: 6px;
    background: var(--bg-body);
    color: var(--text-secondary);
    font-size: 0.85em;
    cursor: pointer;
    transition: all 0.2s ease;
}

.help-filter-btn:hover {
    background: var(--bg-hover);
    border-color: var(--accent);
}

.help-filter-btn.active {
    background: var(--accent);
    color: #fff;
    border-color: var(--accent);
}

/* 问题卡片 */
.help-question-card {
    display: flex;
    flex-direction: row;
    gap: 0;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 10px;
    overflow: hidden;
    cursor: pointer;
    transition: all 0.2s ease;
    height: 145px;
}

.help-question-card:hover {
    border-color: var(--accent);
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    transform: translateY(-2px);
}

/* 问题封面图 */
.help-question-cover {
    width: 25%;
    height: 145px;
    flex-shrink: 0;
    overflow: hidden;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.help-question-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.help-question-cover-placeholder {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5em;
    color: rgba(255,255,255,0.9);
}

/* 问题内容区域 */
.help-question-content {
    padding: 12px 16px;
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0;
    min-width: 0;
    position: relative;
    overflow: hidden;
}

/* 问题类型标签 */
.help-question-type {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    background: #E6F4FF;
    color: #0958D9;
    border-radius: 4px;
    font-size: 0.75em;
    font-weight: 500;
    width: fit-content;
}

/* 问题标题 */
.help-question-title {
    font-size: 1em;
    font-weight: 700;
    color: #000;
    margin: 0 0 6px 0;
    line-height: 1.3;
    max-height: 2.6em;
    overflow: hidden;
    text-overflow: ellipsis;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    word-wrap: break-word;
    word-break: break-word;
}

/* 问题内容预览 */
.help-question-desc {
    font-size: 0.85em;
    color: #999;
    line-height: 1.5;
    margin-bottom: 8px;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    word-break: break-word;
}

/* 问题元信息（作者、班级、时间等） */
.help-question-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 0.85em;
    color: #666;
    margin-top: auto;
}

.help-question-meta-item {
    display: flex;
    align-items: center;
    gap: 4px;
}

.help-question-meta-badge {
    padding: 2px 8px;
    background: #E6F4FF;
    color: #0958D9;
    border-radius: 4px;
    font-size: 0.95em;
}

.help-question-meta-time {
    color: #999;
    margin-left: auto;
}

/* 状态标签 */
.help-status-badge {
    padding: 4px 12px;
    border-radius: 16px;
    font-size: 0.75em;
    font-weight: 500;
    white-space: nowrap;
    flex-shrink: 0;
}

.help-status-badge.status-open {
    background: #3B82F6;
    color: #fff;
}

.help-status-badge.status-resolved {
    background: #10B981;
    color: #fff;
}

.help-status-badge.status-expired {
    background: #F59E0B;
    color: #fff;
}

.help-status-badge.status-closed {
    background: #6B7280;
    color: #fff;
}

/* 截止时间警告 */
.help-deadline-warning {
    color: #D46B08;
    font-weight: 500;
}

/* 发帖表单模态框 */
.help-modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 10000;
}

.help-modal-overlay.show {
    display: flex;
}

.help-modal {
    background: var(--bg-card);
    border-radius: 12px;
    padding: 24px;
    max-width: 600px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
}

.help-modal h3 {
    margin: 0 0 20px 0;
    font-size: 1.2em;
    color: var(--text-primary);
}

.help-form-group {
    margin-bottom: 16px;
}

.help-form-group label {
    display: block;
    margin-bottom: 6px;
    font-size: 0.9em;
    font-weight: 500;
    color: var(--text-primary);
}

.help-form-group label .required {
    color: #FF4D4F;
    margin-left: 2px;
}

.help-form-group input,
.help-form-group select,
.help-form-group textarea {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 6px;
    font-size: 0.92em;
    background: var(--bg-body);
    color: var(--text-primary);
    font-family: inherit;
}

.help-form-group textarea {
    min-height: 120px;
    resize: vertical;
}

.help-form-actions {
    display: flex;
    gap: 12px;
    justify-content: flex-end;
    margin-top: 24px;
}

/* 响应式设计 */
@media (max-width: 1200px) {
    #helpQuestionsGrid {
        grid-template-columns: repeat(2, 1fr) !important;
    }
}

@media (max-width: 768px) {
    #helpQuestionsGrid {
        grid-template-columns: 1fr !important;
    }
    
    .help-question-card {
        height: auto;
        min-height: 120px;
    }
    
    .help-question-cover {
        width: 30%;
    }
    
    .help-header {
        padding: 12px 16px;
    }
    
    .help-question-meta {
        gap: 8px;
        font-size: 0.75em;
    }
}


/* ═══════════ 问题详情页样式 ═══════════ */

/* 返回列表按钮 */
.help-back-btn {
    padding: 8px 20px;
    border: 1px solid #e0dcf5;
    background: #f5f3ff;
    color: #7c6ff7;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.9em;
    font-weight: 500;
    transition: all 0.2s;
}

.help-back-btn:hover {
    background: #ebe7ff;
    border-color: #9b87f5;
}

.help-detail-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 24px;
}

.help-detail-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border);
}

.help-detail-author {
    font-size: 0.9em;
    color: var(--text-primary);
    font-weight: 500;
}

.help-detail-meta-item {
    font-size: 0.85em;
    color: var(--text-muted);
}

.help-detail-title {
    font-size: 1.5em;
    font-weight: 700;
    color: #000;
    margin: 0 0 16px 0;
    line-height: 1.4;
    user-select: text;
    -webkit-user-select: text;
    cursor: text;
}

.help-detail-content {
    font-size: 0.95em;
    color: var(--text-primary);
    line-height: 1.6;
    margin-bottom: 16px;
    user-select: text;
    -webkit-user-select: text;
    cursor: text;
}

.help-detail-image {
    max-width: 48%;
    height: auto;
    border-radius: 8px;
    margin: 8px 1% 8px 0;
    display: inline-block;
    vertical-align: top;
}

.help-detail-actions {
    display: flex;
    gap: 12px;
    margin-top: 20px;
    padding-top: 16px;
    border-top: 1px solid var(--border);
}

/* 回答列表 */
.help-answer-item {
    padding: 12px 16px;
    background: #fff;
    border: 1px solid #ddd;
    border-radius: 8px;
    margin-bottom: 10px;
    animation: fadeInUp 0.3s ease;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.help-answer-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.help-answer-author {
    font-size: 0.9em;
    color: var(--text-primary);
    font-weight: 500;
}

.help-answer-time {
    font-size: 0.8em;
    color: var(--text-muted);
}

.help-answer-content {
    font-size: 0.9em;
    color: var(--text-primary);
    line-height: 1.5;
    user-select: text;
    -webkit-user-select: text;
    cursor: text;
}

.help-answer-delete-btn {
    padding: 2px 8px;
    font-size: 0.75em;
    border: 1px solid #dc3545;
    background: #fff;
    color: #dc3545;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    line-height: 1;
}

.help-answer-delete-btn:hover {
    background: #dc3545;
    color: #fff;
}

.help-answer-actions {
    margin-top: 12px;
    display: flex;
    gap: 12px;
}

.help-answer-btn {
    padding: 4px 12px;
    font-size: 0.8em;
    border: 1px solid var(--border);
    background: var(--bg-body);
    color: var(--text-secondary);
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s;
}

.help-answer-btn:hover {
    background: var(--bg-hover);
    border-color: var(--accent);
}

/* 回答图片样式 */
.help-answer-images {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 12px;
}

.help-answer-image {
    max-width: 12%;
    height: auto;
    border-radius: 6px;
    object-fit: cover;
    cursor: pointer;
    transition: transform 0.2s;
}

.help-answer-image:hover {
    transform: scale(1.02);
}

/* 评论表单样式 - 淡紫色主题 */
.help-answer-form {
    margin-top: 16px;
}

/* 上传按钮区域 - 淡紫色背景，紧贴输入框顶部 */
.help-answer-upload-area {
    background: linear-gradient(to bottom, #f5f3ff 0%, #faf9ff 100%);
    padding: 10px 16px;
    border-radius: 8px 8px 0 0;
}

.help-answer-upload-btn {
    cursor: pointer;
    font-size: 0.85em;
    color: #6b5bd4;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 8px;
    border-radius: 4px;
    transition: background 0.2s;
}

.help-answer-upload-btn:hover {
    background: rgba(155, 135, 245, 0.15);
}

/* 白色输入区域容器 */
.help-answer-input-container {
    background: #fff;
    border-left: 1px solid #ddd;
    border-right: 1px solid #ddd;
    padding: 12px 16px;
}

.help-answer-textarea {
    width: 100%;
    min-height: 80px;
    padding: 0;
    border: none;
    font-size: 0.9em;
    resize: vertical;
    background: transparent;
    color: var(--text-primary);
    font-family: inherit;
    outline: none;
}

.help-answer-textarea::placeholder {
    color: #bbb;
}

.help-answer-images-preview {
    display: none;
    margin-top: 12px;
    flex-wrap: wrap;
    gap: 8px;
}

.help-answer-images-preview:not(:empty) {
    display: flex;
}

/* 底部淡紫色区域 */
.help-answer-form-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 16px;
    background: linear-gradient(to bottom, #faf9ff 0%, #f5f3ff 100%);
    border-radius: 0 0 8px 8px;
}

.help-answer-form-title {
    font-size: 0.85em;
    color: #9b87f5;
    font-weight: 500;
}

.help-answer-submit-btn {
    padding: 8px 24px;
    font-size: 0.85em;
    border-radius: 20px;
    background: #9b87f5;
    color: #fff;
    border: none;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.2s;
}

.help-answer-submit-btn:hover {
    background: #8a76e4;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(155, 135, 245, 0.3);
}

.help-answer-submit-btn:active {
    transform: translateY(0);
}

/* 图片查看器 */
.image-viewer-backdrop {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.9);
    z-index: 10000;
    align-items: center;
    justify-content: center;
    cursor: zoom-out;
}

.image-viewer-backdrop.show {
    display: flex;
}

.image-viewer-image {
    max-width: 90%;
    max-height: 90%;
    object-fit: contain;
    animation: zoomIn 0.2s ease;
}

@keyframes zoomIn {
    from {
        transform: scale(0.8);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

.image-viewer-close {
    position: absolute;
    top: 20px;
    right: 30px;
    background: rgba(255, 255, 255, 0.2);
    border: 2px solid #fff;
    color: #fff;
    font-size: 2em;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
}

.image-viewer-close:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}