/* ============================================================
   question_bank.css —— 数学题库模块样式
   复用主系统 CSS 变量（--primary / --success / --warning / --danger）
   ============================================================ */

/* 题库弹窗（比普通 modal 更大） */
.qb-modal-overlay { z-index: 1100; }
/* 题库内嵌套弹出的「题目详情」必须盖在题库弹窗上方（1100 < z < 1200 选题器） */
#qbDetailModal.modal-overlay { z-index: 1150; }
.qb-modal {
    width: 1000px; max-width: 95vw; max-height: 88vh;
    display: flex; flex-direction: column;
}
.qb-modal-body { padding: 16px 20px; overflow-y: auto; flex: 1; }

/* 头部操作区 */
.qb-header-actions { display: flex; align-items: center; gap: 8px; }

/* Tab 栏 */
.qb-tabs {
    display: flex; gap: 0; border-bottom: 2px solid var(--border);
    padding: 0 20px;
}
.qb-tab {
    padding: 10px 20px; font-size: .88rem; cursor: pointer;
    color: var(--text-secondary); border-bottom: 2px solid transparent;
    margin-bottom: -2px; transition: all .2s; user-select: none;
}
.qb-tab:hover { color: var(--primary); }
.qb-tab.active { color: var(--primary); border-bottom-color: var(--primary); font-weight: 600; }

/* 筛选栏 */
.qb-filter-bar {
    display: flex; gap: 8px; flex-wrap: wrap; align-items: center;
    margin-bottom: 16px; padding: 12px; background: #fafafa;
    border-radius: 8px;
}
.qb-filter-bar input[type="text"] {
    flex: 1; min-width: 160px; padding: 8px 10px;
    border: 1px solid #d9d9d9; border-radius: 6px; font-size: .85rem; outline: none;
    transition: border-color .2s;
}
.qb-filter-bar input[type="text"]:focus { border-color: var(--primary); }
.qb-filter-bar select {
    padding: 8px 10px; border: 1px solid #d9d9d9; border-radius: 6px;
    font-size: .82rem; outline: none; background: #fff; cursor: pointer;
    transition: border-color .2s;
}
.qb-filter-bar select:focus { border-color: var(--primary); }

/* 题目卡片 */
.qb-list-body { display: flex; flex-direction: column; gap: 12px; }
.qb-card {
    background: #fff; border: 1px solid var(--border); border-radius: 8px;
    padding: 14px 16px; transition: all .2s;
}
.qb-card:hover { border-color: var(--primary); box-shadow: 0 2px 8px rgba(102,126,234,.08); }
.qb-card-head {
    display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
    margin-bottom: 8px;
}
.qb-card-body {
    font-size: .9rem; line-height: 1.7; color: var(--text);
    max-height: 120px; overflow: hidden; position: relative;
}
.qb-card-body::after {
    content: ''; position: absolute; bottom: 0; left: 0; right: 0;
    height: 30px; background: linear-gradient(transparent, #fff);
    pointer-events: none;
}
.qb-card-foot {
    display: flex; justify-content: space-between; align-items: center;
    margin-top: 10px; font-size: .8rem; color: #999; flex-wrap: wrap; gap: 8px;
}
.qb-actions { display: flex; gap: 6px; }

/* 徽章 */
.qb-badge {
    display: inline-block; padding: 2px 8px; border-radius: 4px;
    font-size: .75rem; font-weight: 500;
}
.qb-badge-type { background: #e6f7ff; color: #1890ff; }
.qb-badge-answer { background: #f6ffed; color: #389e0d; }
.qb-badge-info { background: #f0f5ff; color: #667eea; }
.qb-badge-diag { background: #fff2e8; color: #ff7a45; }
/* 📘 课后习题：绿色系 */
.qb-badge-post { background: #f6ffed; color: #52c41a; }
/* 🧩 综合题：紫色系（紫-淡紫底+深紫字） */
.qb-badge-comp { background: #f9f0ff; color: #722ed1; }

/* 复选框标签（编辑表单） */
.qb-checkbox-label {
    display: flex; align-items: center; gap: 8px; cursor: pointer;
    font-weight: 500; font-size: .88rem; color: var(--text);
}
.qb-checkbox-label input[type="checkbox"] {
    width: 16px; height: 16px; cursor: pointer; accent-color: var(--primary);
}
.qb-loc { font-size: .78rem; color: #888; flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.qb-date { font-size: .75rem; color: #bbb; }
.qb-source { color: #aaa; }
.qb-tags { color: #aaa; }
.qb-btn-del:hover { color: var(--danger); border-color: var(--danger); }

/* 分页 */
.qb-pager {
    display: flex; align-items: center; justify-content: center; gap: 12px;
    padding: 16px 0; font-size: .85rem;
}
.qb-count { color: #888; }
.qb-page-info { color: #555; font-weight: 500; }

/* 空状态 / 加载 */
.qb-empty, .qb-loading {
    text-align: center; padding: 60px 20px; color: #999; font-size: .9rem;
}

/* 编辑表单 */
.qb-edit-form { max-width: 100%; }
.qb-edit-form .form-group textarea {
    width: 100%; padding: 10px 12px; border: 1px solid #d9d9d9;
    border-radius: 6px; font-size: .88rem; outline: none;
    transition: border-color .2s; font-family: inherit; resize: vertical;
}
.qb-edit-form .form-group textarea:focus { border-color: var(--primary); }
.qb-edit-form .form-group input[type="text"] {
    width: 100%; padding: 8px 10px; border: 1px solid #d9d9d9;
    border-radius: 6px; font-size: .85rem; outline: none;
}
.qb-edit-form .form-group input[type="text"]:focus { border-color: var(--primary); }
.qb-edit-form .form-group select {
    width: 100%; padding: 8px 10px; border: 1px solid #d9d9d9;
    border-radius: 6px; font-size: .85rem; outline: none; background: #fff;
}
.qb-chapter-desc {
    font-size: .8rem; color: #888; margin: -8px 0 12px; padding: 6px 10px;
    background: #f0f5ff; border-radius: 4px;
}

/* LaTeX 实时预览 */
.qb-preview-box {
    margin: 12px 0; padding: 14px; background: #fafafa;
    border: 1px dashed #d9d9d9; border-radius: 6px;
}
.qb-preview-label {
    font-size: .78rem; color: #999; margin-bottom: 8px;
}
.qb-preview {
    font-size: .9rem; line-height: 1.7; color: var(--text);
    min-height: 24px;
}
.qb-preview:empty::before { content: '（输入题干后将显示预览）'; color: #ccc; }

/* 统计面板 */
.qb-stats-body { padding: 8px 0; }
.qb-stats-grid {
    display: flex; gap: 16px; margin-bottom: 24px; flex-wrap: wrap;
}
.qb-stat-card {
    flex: 1; min-width: 120px; background: #fff; border: 1px solid var(--border);
    border-radius: 8px; padding: 20px; text-align: center;
}
.qb-stat-num {
    font-size: 2rem; font-weight: 700; color: var(--primary);
    line-height: 1.2;
}
.qb-stat-label { font-size: .82rem; color: #999; margin-top: 4px; }
.qb-stats-section { margin-bottom: 24px; }
.qb-stats-section h5 { font-size: .95rem; margin-bottom: 12px; color: var(--text); }
.qb-bar-chart { display: flex; flex-direction: column; gap: 10px; }
.qb-bar-item {
    display: flex; align-items: center; gap: 10px; font-size: .83rem;
}
.qb-bar-label {
    min-width: 120px; text-align: right; overflow: hidden;
    text-overflow: ellipsis; white-space: nowrap; color: #666;
}
.qb-bar-track {
    flex: 1; height: 22px; background: #f0f0f0; border-radius: 11px; overflow: hidden;
}
.qb-bar-fill {
    height: 100%; border-radius: 11px; transition: width .6s ease;
    min-width: 4px;
}
.qb-bar-count {
    min-width: 30px; font-weight: 600; color: #555;
}

/* 导入区 */
.qb-import-area {
    background: #fafafa; border: 1px solid var(--border); border-radius: 8px;
    padding: 16px; margin-bottom: 16px;
}
.qb-import-area h5 { margin-bottom: 8px; }
.qb-import-area textarea {
    width: 100%; padding: 10px; border: 1px solid #d9d9d9; border-radius: 6px;
    font-size: .85rem; font-family: 'Courier New', monospace; resize: vertical;
    min-height: 200px;
}
.qb-hint { font-size: .78rem; color: #999; margin-bottom: 10px; line-height: 1.5; }

/* 详情弹窗 */
.qb-detail-modal { width: 800px; max-width: 95vw; }
.qb-detail-meta { display: flex; gap: 6px; flex-wrap: wrap; margin-bottom: 16px; }
.qb-detail-section { margin-bottom: 20px; }
.qb-detail-section h5 {
    font-size: .9rem; color: var(--primary); margin-bottom: 8px;
    padding-bottom: 4px; border-bottom: 1px solid var(--border);
}
.qb-detail-content {
    font-size: .92rem; line-height: 1.8; color: var(--text);
    padding: 12px; background: #fafafa; border-radius: 6px;
}
.qb-detail-answer { background: #f6ffed; border: 1px solid #d9f7be; }
.qb-detail-foot {
    display: flex; gap: 20px; font-size: .82rem; color: #999;
    padding-top: 12px; border-top: 1px solid var(--border);
}

/* 响应式 */
@media (max-width: 768px) {
    .qb-modal { width: 100vw; max-width: 100vw; max-height: 100vh; border-radius: 0; }
    .qb-modal-body { padding: 12px; }
    .qb-filter-bar { flex-direction: column; }
    .qb-filter-bar input, .qb-filter-bar select { width: 100%; }
    .qb-bar-label { min-width: 80px; font-size: .75rem; }
    .qb-stats-grid { flex-direction: column; }
    .qb-stat-card { min-width: auto; }
}

/* ============================================================
   选题子弹窗（从题库选前测题加入诊断）
   ============================================================ */
.qb-picker-overlay { z-index: 1200; }
.qb-picker-modal {
    width: 800px; max-width: 95vw; max-height: 85vh;
    display: flex; flex-direction: column;
}
.qb-picker-body {
    padding: 16px 20px; overflow-y: auto; flex: 1;
}
.qb-picker-hint {
    font-size: .8rem; color: #888; margin-bottom: 12px;
    padding: 8px 12px; background: #fff7e6; border-radius: 4px;
    border-left: 3px solid #faad14;
}
.qb-picker-list {
    display: flex; flex-direction: column; gap: 8px;
    max-height: 50vh; overflow-y: auto;
}
.qb-picker-item {
    display: flex; gap: 12px; padding: 12px;
    background: #fff; border: 1px solid var(--border); border-radius: 8px;
    cursor: pointer; transition: all .2s;
}
.qb-picker-item:hover {
    border-color: var(--primary); background: #f9faff;
}
.qb-picker-item.selected {
    border-color: var(--primary); background: #f0f5ff;
    box-shadow: 0 0 0 2px rgba(102,126,234,.15);
}
.qb-picker-item input[type="checkbox"] {
    margin-top: 4px; flex-shrink: 0; width: 18px; height: 18px;
    cursor: pointer; accent-color: var(--primary);
}
.qb-picker-item-body { flex: 1; min-width: 0; }
.qb-picker-item-head {
    display: flex; align-items: center; gap: 6px; margin-bottom: 6px;
    flex-wrap: wrap;
}
.qb-picker-item-stem {
    font-size: .85rem; line-height: 1.6; color: var(--text); font-weight: 600;
    display: -webkit-box; -webkit-line-clamp: 2;
    -webkit-box-orient: vertical; overflow: hidden;
}
.qb-picker-item-opts {
    margin-top: 6px;
    display: grid; grid-template-columns: 1fr 1fr; gap: 3px 18px;
}
.qb-picker-item-opt {
    font-size: .8rem; line-height: 1.55; color: #555;
    min-width: 0;
}
.qb-picker-item-opt .katex { font-size: 1em; }
.qb-picker-count {
    font-size: .88rem; color: #666; flex: 1;
}
.qb-picker-count strong { color: var(--primary); font-size: 1.1rem; }

/* 诊断页集成按钮 */
.qb-diag-actions {
    display: flex; gap: 8px; flex-wrap: wrap; margin-top: 8px;
}

/* 教案页保存按钮 */
.qb-save-btn {
    display: inline-flex; align-items: center; gap: 4px;
}

@media (max-width: 768px) {
    .qb-picker-modal { width: 100vw; max-width: 100vw; max-height: 100vh; border-radius: 0; }
    .qb-picker-body { padding: 12px; }
    .qb-picker-list { max-height: 60vh; }
}

/* ============================================================
   批量生成 Tab
   ============================================================ */
.qb-batch-config {
    background: #f9faff; border: 1px solid #e8ecf5;
    border-radius: 8px; padding: 16px; margin-bottom: 16px;
}
.qb-batch-config-row {
    display: flex; gap: 16px; align-items: flex-end;
    margin-bottom: 12px; flex-wrap: wrap;
}
.qb-batch-config-row:last-child { margin-bottom: 0; }

.qb-batch-progress {
    margin: 16px 0;
}
.qb-batch-progress-bar {
    height: 12px; background: #f0f0f0; border-radius: 6px;
    overflow: hidden; margin-bottom: 8px;
}
.qb-batch-progress-fill {
    height: 100%; background: linear-gradient(90deg, var(--primary), #a78bfa);
    border-radius: 6px; width: 0; transition: width .3s ease;
}
.qb-batch-progress-info {
    display: flex; justify-content: space-between;
    font-size: .85rem; color: #666;
}

.qb-batch-log {
    background: #1a1a2e; color: #e0e0e0;
    border-radius: 8px; padding: 12px;
    max-height: 240px; overflow-y: auto;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: .8rem; line-height: 1.6;
    margin-top: 16px;
}
.qb-batch-log-item {
    padding: 2px 0; border-bottom: 1px solid #2a2a4a;
}
.qb-batch-log-time {
    color: #666; margin-right: 8px;
}

/* ============================================================
   学情联动 · 推荐
   ============================================================ */
.qb-stats-input-row {
    display: flex; gap: 8px; margin: 12px 0;
}
.qb-recommend-result {
    margin-top: 12px;
}
.qb-recommend-summary {
    background: #f6ffed; color: #389e0d;
    padding: 8px 12px; border-radius: 6px;
    font-size: .85rem; margin-bottom: 12px;
}
.qb-recommend-group {
    margin-bottom: 16px;
}
.qb-recommend-kw {
    font-size: .85rem; margin-bottom: 6px; color: #666;
}
.qb-recommend-kw strong { color: var(--primary); }
.qb-recommend-list {
    display: flex; flex-direction: column; gap: 6px;
}
.qb-recommend-item {
    background: #fff; border: 1px solid var(--border);
    border-radius: 6px; padding: 8px 12px;
}
.qb-recommend-item-head {
    display: flex; align-items: center; gap: 6px; margin-bottom: 4px;
}
.qb-recommend-item-body {
    font-size: .82rem; line-height: 1.5; color: var(--text);
    max-height: 60px; overflow: hidden;
    display: -webkit-box; -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
}

/* ============================================================
   Word 导入拆题（qb-docx-*）
   ============================================================ */
.qb-docx-notice {
    background: #fffbe6; border: 1px solid #ffe58f; color: #874d00;
    border-radius: 8px; padding: 10px 14px; font-size: .85rem;
    line-height: 1.6; margin-bottom: 14px;
}
.qb-docx-notice b { color: #d46b08; }

/* 拖拽上传区 */
.qb-docx-drop {
    border: 2px dashed #d9d9d9; border-radius: 12px;
    padding: 34px 20px; text-align: center; cursor: pointer;
    transition: all .2s; background: #fafafa;
}
.qb-docx-drop:hover, .qb-docx-drop.dragover {
    border-color: var(--primary); background: #f0f2ff;
}
.qb-docx-drop.dragover { border-style: solid; box-shadow: 0 4px 16px rgba(102,126,234,.15); }
.qb-docx-drop-icon { font-size: 2.2rem; margin-bottom: 8px; }
.qb-docx-drop-title { font-size: .95rem; font-weight: 600; color: var(--text); }
.qb-docx-drop-hint { font-size: .78rem; color: var(--text-secondary); margin-top: 6px; }

/* 文件栏 */
.qb-docx-filebar {
    display: flex; align-items: center; gap: 10px;
    background: #f0f5ff; border: 1px solid #c6d4ff;
    border-radius: 8px; padding: 10px 14px; margin-top: 12px;
    font-size: .88rem;
}
.qb-docx-filebar span:first-child { flex: 1; }

/* 状态区 */
.qb-docx-status { margin-top: 12px; font-size: .85rem; }
.qb-docx-step { color: var(--primary); font-weight: 600; }
.qb-docx-step.done { color: var(--success, #52c41a); }
.qb-docx-meta {
    display: block; margin-top: 6px; color: var(--text-secondary); font-size: .8rem;
}
.qb-docx-stream {
    margin-top: 8px; padding: 10px; background: #1f1f1f; color: #d4d4d4;
    border-radius: 8px; font-size: .75rem; line-height: 1.5;
    max-height: 140px; overflow: hidden; white-space: pre-wrap; word-break: break-all;
}
.qb-docx-error { color: var(--danger, #ff4d4f); font-weight: 600; }

/* 图片区 */
.qb-docx-images {
    margin-top: 14px; background: #fafafa;
    border: 1px solid var(--border); border-radius: 8px; padding: 12px;
}
.qb-docx-images-head {
    display: flex; align-items: center; justify-content: space-between; margin-bottom: 10px;
}
.qb-docx-images-grid {
    display: flex; flex-wrap: wrap; gap: 10px;
}
.qb-docx-thumb {
    width: 110px; margin: 0; text-align: center;
}
.qb-docx-thumb img {
    width: 110px; height: 80px; object-fit: contain;
    background: #fff; border: 1px solid var(--border); border-radius: 6px; padding: 4px;
}
.qb-docx-thumb figcaption {
    font-size: .7rem; color: var(--text-secondary); margin-top: 4px;
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.qb-docx-images-hint {
    margin-top: 10px; font-size: .78rem; color: var(--text-secondary);
}

/* 结果区 */
.qb-docx-results { margin-top: 16px; }
.qb-draft-toolbar {
    display: flex; align-items: center; gap: 14px;
    padding: 10px 12px; background: #f0f5ff; border-radius: 8px;
    margin-bottom: 12px;
}
.qb-draft-toolbar .btn { margin-left: auto; }
.qb-draft-count { font-size: .85rem; color: var(--text-secondary); }
.qb-draft-count b { color: var(--primary); }
.qb-draft-check {
    display: flex; align-items: center; gap: 6px;
    font-size: .85rem; cursor: pointer; user-select: none;
}
.qb-draft-list {
    display: flex; flex-direction: column; gap: 10px;
}

/* 草稿卡片 */
.qb-draft-card {
    background: #fff; border: 1px solid var(--border);
    border-radius: 10px; padding: 12px 14px; transition: opacity .2s;
}
.qb-draft-card.unselected { opacity: .45; }
.qb-draft-card.needs-check {
    border-color: #ffc53d; background: #fffdf0;
}
.qb-draft-head {
    display: flex; align-items: center; gap: 8px; margin-bottom: 8px;
}
.qb-draft-head-actions { margin-left: auto; display: flex; gap: 6px; }
.qb-draft-badge {
    font-size: .72rem; padding: 2px 8px; border-radius: 10px;
    border: 1px solid var(--border); color: var(--text-secondary);
}
.qb-draft-badge.type { background: #f0f5ff; border-color: #c6d4ff; color: #2f54eb; }
.qb-draft-badge.warn { background: #fff7e6; border-color: #ffd591; color: #d46b08; }
.qb-draft-badge.diff { background: #fff; font-weight: 600; }
.qb-draft-tags {
    display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 8px;
}
.qb-draft-tag {
    font-size: .72rem; padding: 2px 8px; border-radius: 4px;
    background: #f5f5f5; color: var(--text-secondary);
}
.qb-draft-tag.muted { color: #bfbfbf; }
.qb-draft-body { font-size: .88rem; }
.qb-draft-text { line-height: 1.7; }
.qb-draft-answer {
    margin-top: 10px; padding: 8px 12px;
    background: #fafafa; border-radius: 6px;
}
.qb-draft-answer.empty { background: transparent; padding: 8px 0 0; }
.qb-draft-answer-label {
    display: inline-block; font-size: .75rem; color: var(--text-secondary);
    margin-bottom: 4px; font-weight: 600;
}
.qb-draft-none { font-size: .8rem; color: #bfbfbf; }
.qb-draft-edit {
    width: 100%; min-height: 120px; padding: 8px 10px;
    border: 1px solid var(--primary); border-radius: 6px;
    font-size: .88rem; line-height: 1.6; resize: vertical; outline: none;
}
.qb-draft-edit-actions { margin-top: 6px; display: flex; gap: 6px; }