:root {
  --bg-page: #f1f5f9;
  --bg-card: #ffffff;
  --bg-header: linear-gradient(135deg, #0f172a 0%, #1e3a8a 60%, #0f766e 100%);
  --text-main: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --primary: #1d4ed8;
  --primary-hover: #1e40af;
  --teal: #0f766e;
  --amber: #d97706;
  --amber-bg: #fffbeb;
  --amber-border: #fcd34d;
  --green: #15803d;
  --green-bg: #dcfce7;
  --red: #b91c1c;
  --red-bg: #fee2e2;
  --border-color: #e2e8f0;
  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.08);
  --shadow-md: 0 4px 14px rgba(15, 23, 42, 0.09);
  --radius-md: 10px;
  --radius-lg: 14px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background-color: var(--bg-page);
  color: var(--text-main);
  line-height: 1.5;
  min-height: 100vh;
}

/* 顶部导航栏 */
.top-header {
  background: var(--bg-header);
  color: #ffffff;
  padding: 16px 24px 0 24px;
  box-shadow: 0 4px 18px rgba(15, 23, 42, 0.2);
}

.header-main {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
  padding-bottom: 14px;
}

.uni-badge {
  display: inline-block;
  background: rgba(255, 255, 255, 0.16);
  border: 1px solid rgba(255, 255, 255, 0.3);
  padding: 2px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.5px;
  margin-bottom: 4px;
}

.course-title {
  font-size: 22px;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.phase-tag {
  font-size: 12px;
  background: #f59e0b;
  color: #0f172a;
  padding: 2px 9px;
  border-radius: 6px;
  font-weight: 700;
}

.project-subtitle {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.88);
  margin-top: 3px;
}

.stats-bar {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.stat-card {
  background: rgba(255, 255, 255, 0.12);
  backdrop-filter: blur(6px);
  border: 1px solid rgba(255, 255, 255, 0.22);
  border-radius: 10px;
  padding: 8px 14px;
  min-width: 140px;
  display: flex;
  flex-direction: column;
}

.stat-card.stat-highlight {
  background: rgba(245, 158, 11, 0.22);
  border-color: rgba(251, 191, 36, 0.65);
}

.stat-label {
  font-size: 11px;
  color: rgba(255, 255, 255, 0.82);
}

.stat-value {
  font-size: 20px;
  font-weight: 800;
  color: #ffffff;
  line-height: 1.25;
}

.stat-unit {
  font-size: 11px;
  color: rgba(255, 255, 255, 0.78);
}

/* 工作台切换 Tab */
.workspace-tabs {
  display: flex;
  gap: 8px;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding-top: 10px;
}

.tab-btn {
  background: rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.88);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-bottom: none;
  padding: 10px 18px;
  border-radius: 10px 10px 0 0;
  cursor: pointer;
  font-size: 14px;
  font-weight: 600;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: all 0.18s ease;
}

.tab-btn:hover {
  background: rgba(255, 255, 255, 0.2);
  color: #ffffff;
}

.tab-btn.active {
  background: var(--bg-page);
  color: #0f172a;
  border-color: var(--bg-page);
  box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.1);
}

.tab-pill {
  font-size: 11px;
  padding: 1px 7px;
  border-radius: 99px;
  background: rgba(29, 78, 216, 0.14);
  color: #1e40af;
}

.tab-btn:not(.active) .tab-pill {
  background: rgba(255, 255, 255, 0.2);
  color: #ffffff;
}

/* 主工作区容器 */
.workspace-container {
  padding: 14px 20px 28px;
  max-width: 1920px;
  margin: 0 auto;
}

.workspace-panel {
  display: none;
}

.workspace-panel.active {
  display: block;
}

/* 工具栏与筛选栏 */
.graph-toolbar {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 10px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 12px;
  box-shadow: var(--shadow-sm);
}

.filter-group {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
}

.filter-group input,
.filter-group select {
  padding: 6px 10px;
  border: 1px solid #cbd5e1;
  border-radius: 6px;
  font-size: 13px;
  background: #f8fafc;
  color: var(--text-main);
}

#searchInput {
  width: 220px;
}

.toolbar-actions {
  display: flex;
  gap: 8px;
  align-items: center;
}

/* 按钮通用样式 */
.btn {
  padding: 7px 14px;
  border-radius: 7px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  border: 1px solid transparent;
  transition: all 0.15s ease;
}

.btn-primary {
  background: var(--primary);
  color: #ffffff;
}

.btn-primary:hover {
  background: var(--primary-hover);
}

.btn-outline {
  background: #ffffff;
  border-color: #cbd5e1;
  color: var(--text-main);
}

.btn-outline:hover {
  background: #f1f5f9;
}

.btn-subtle {
  background: #f1f5f9;
  color: var(--text-secondary);
}

.btn-subtle:hover {
  background: #e2e8f0;
}

.btn-danger-outline {
  background: #fff1f2;
  border-color: #fecdd3;
  color: #be123c;
}

.btn-danger-outline:hover {
  background: #ffe4e6;
}

.btn-block {
  flex: 1;
}

.btn-lg {
  padding: 11px 22px;
  font-size: 15px;
}

.btn-mini {
  padding: 3px 9px;
  font-size: 12px;
  border: 1px solid #cbd5e1;
  border-radius: 5px;
  background: #ffffff;
  cursor: pointer;
}

.btn-mini:hover {
  background: #f1f5f9;
}

/* 图谱主网格：左侧画布 + 右侧溯源审阅面板 */
.graph-main-grid {
  display: grid;
  grid-template-columns: 1fr 445px;
  gap: 14px;
  align-items: start;
}

.graph-canvas-wrapper {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.canvas-header-overlay {
  padding: 10px 14px;
  border-bottom: 1px solid var(--border-color);
  background: #f8fafc;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.legend-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  background: #ffffff;
  padding: 3px 9px;
  border-radius: 99px;
  border: 1px solid #e2e8f0;
  cursor: pointer;
}

.legend-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
}

.canvas-controls {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.canvas-tip {
  font-size: 12px;
  color: var(--text-secondary);
}

.graph-svg {
  width: 100%;
  height: 590px;
  background: radial-gradient(circle at center, #f8fafc 0%, #eff6ff 100%);
  cursor: grab;
  user-select: none;
}

.graph-svg:active {
  cursor: grabbing;
}

/* 底部节点快览条 */
.node-quick-strip {
  border-top: 1px solid var(--border-color);
  padding: 8px 14px;
  background: #f8fafc;
}

.strip-title {
  font-size: 12px;
  font-weight: 700;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.strip-list {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-bottom: 4px;
}

.quick-node-pill {
  flex-shrink: 0;
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 6px;
  background: #ffffff;
  border: 1px solid #cbd5e1;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 5px;
}

.quick-node-pill.active {
  background: #eff6ff;
  border-color: var(--primary);
  color: var(--primary);
  font-weight: 700;
}

/* 右侧详情与审阅侧边栏 */
.inspector-sidebar {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 16px;
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-height: 760px;
  overflow-y: auto;
}

.inspector-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 10px;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 10px;
}

.inspector-kicker {
  font-size: 10px;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: 0.8px;
}

.inspector-header h2 {
  font-size: 17px;
  line-height: 1.3;
  color: var(--text-main);
}

.status-badge {
  flex-shrink: 0;
  font-size: 12px;
  font-weight: 700;
  padding: 3px 10px;
  border-radius: 99px;
}

.status-approved {
  background: var(--green-bg);
  color: var(--green);
}

.status-pending {
  background: #fef3c7;
  color: #b45309;
}

.status-needs_revision {
  background: var(--red-bg);
  color: var(--red);
}

/* 核心原文溯源凭证金卡 */
.provenance-box {
  background: var(--amber-bg);
  border: 2px solid var(--amber-border);
  border-radius: 10px;
  padding: 12px;
}

.provenance-title {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 13px;
  font-weight: 800;
  color: #92400e;
  margin-bottom: 8px;
}

.verified-pill {
  background: #d97706;
  color: #ffffff;
  font-size: 11px;
  padding: 1px 8px;
  border-radius: 99px;
}

.prov-row {
  font-size: 12.5px;
  margin-bottom: 5px;
  line-height: 1.4;
}

.prov-label {
  color: #78350f;
  font-weight: 700;
}

.prov-value {
  color: #0f172a;
}

.prov-location {
  background: #fef3c7;
  color: #92400e;
  padding: 1px 6px;
  border-radius: 4px;
  font-weight: 600;
}

.prov-excerpt-wrap {
  margin-top: 6px;
}

.prov-excerpt {
  margin-top: 4px;
  background: #ffffff;
  border-left: 3px solid #d97706;
  padding: 7px 10px;
  font-size: 12px;
  color: #1e293b;
  border-radius: 0 6px 6px 0;
}

/* 教师审阅操作区 */
.review-action-box,
.node-edit-form,
.relations-box {
  background: #f8fafc;
  border: 1px solid #e2e8f0;
  border-radius: 10px;
  padding: 11px 12px;
}

.section-subtitle {
  font-size: 13px;
  font-weight: 700;
  color: #1e293b;
  margin-bottom: 8px;
}

.review-status-buttons {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 6px;
  margin-bottom: 8px;
}

.status-btn {
  padding: 6px 8px;
  font-size: 12px;
  font-weight: 700;
  border-radius: 6px;
  border: 1px solid #cbd5e1;
  background: #ffffff;
  cursor: pointer;
}

.status-btn.active[data-status="approved"] {
  background: #15803d;
  color: #ffffff;
  border-color: #15803d;
}

.status-btn.active[data-status="pending"] {
  background: #d97706;
  color: #ffffff;
  border-color: #d97706;
}

.status-btn.active[data-status="needs_revision"] {
  background: #b91c1c;
  color: #ffffff;
  border-color: #b91c1c;
}

.form-row {
  display: flex;
  flex-direction: column;
  gap: 3px;
  margin-bottom: 8px;
}

.form-row-inline {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.form-row label,
.form-row-inline label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
}

.req {
  color: #dc2626;
}

.form-row input,
.form-row select,
.form-row textarea,
.form-row-inline input {
  padding: 6px 9px;
  border: 1px solid #cbd5e1;
  border-radius: 6px;
  font-size: 12.5px;
  font-family: inherit;
  background: #ffffff;
}

.form-actions {
  display: flex;
  gap: 8px;
  margin-top: 6px;
}

.save-feedback {
  font-size: 12px;
  font-weight: 600;
  margin-top: 6px;
  min-height: 18px;
}

.relation-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 5px;
  margin-bottom: 8px;
  max-height: 120px;
  overflow-y: auto;
}

.relation-item {
  font-size: 12px;
  background: #ffffff;
  border: 1px solid #e2e8f0;
  border-radius: 6px;
  padding: 4px 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.add-edge-inline {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.add-edge-inline select,
.add-edge-inline input {
  padding: 5px 8px;
  font-size: 12px;
  border: 1px solid #cbd5e1;
  border-radius: 6px;
}

/* 工作台 2：上传与台账 */
.upload-grid {
  display: grid;
  grid-template-columns: 440px 1fr;
  gap: 18px;
  align-items: start;
}

.upload-drop-card,
.materials-ledger-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-md);
}

.card-desc {
  font-size: 13px;
  color: var(--text-secondary);
  margin: 6px 0 14px;
}

.dropzone {
  border: 2px dashed #3b82f6;
  background: #eff6ff;
  border-radius: 12px;
  padding: 26px 18px;
  text-align: center;
  cursor: pointer;
  position: relative;
  margin-bottom: 14px;
  transition: background 0.15s ease;
}

.dropzone:hover,
.dropzone.dragover {
  background: #dbeafe;
}

.dropzone input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

.dropzone-icon {
  font-size: 36px;
  margin-bottom: 6px;
}

.dropzone-title {
  font-size: 14px;
  font-weight: 700;
  color: #1e3a8a;
}

.dropzone-hint {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 4px;
}

.upload-status-msg {
  margin-top: 10px;
  font-size: 13px;
  font-weight: 600;
}

.materials-table-wrap {
  overflow-x: auto;
}

.materials-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

.materials-table th,
.materials-table td {
  padding: 11px 12px;
  border-bottom: 1px solid var(--border-color);
  text-align: left;
}

.materials-table th {
  background: #f8fafc;
  font-weight: 700;
  color: var(--text-secondary);
}

/* 工作台 3：智能问答与资源发现 */
.qa-layout {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  gap: 18px;
  align-items: start;
}

.qa-intro-card,
.qa-response-card,
.qa-right-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-md);
}

.qa-response-card {
  margin-top: 14px;
}

.preset-questions {
  margin: 14px 0;
}

.preset-title {
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 8px;
}

.preset-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.chip-btn {
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  color: #1e40af;
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 12.5px;
  font-weight: 600;
  cursor: pointer;
  text-align: left;
}

.chip-btn:hover {
  background: #dbeafe;
}

.qa-input-bar {
  display: flex;
  gap: 10px;
  margin-top: 12px;
}

.qa-input-bar input {
  flex: 1;
  padding: 10px 14px;
  border: 1px solid #cbd5e1;
  border-radius: 8px;
  font-size: 14px;
}

.qa-answer-box {
  line-height: 1.65;
  font-size: 14px;
  color: #1e293b;
  white-space: pre-line;
}

.qa-references-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 10px;
}

.ref-card {
  border: 1px solid #fcd34d;
  background: #fffbeb;
  border-radius: 10px;
  padding: 12px;
}

.ref-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 6px;
}

/* Modal 弹窗 */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.modal-backdrop.hidden {
  display: none;
}

.modal-card {
  background: #ffffff;
  border-radius: 14px;
  width: 540px;
  max-width: 95vw;
  padding: 20px;
  box-shadow: 0 12px 32px rgba(15, 23, 42, 0.25);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 14px;
}

.btn-close {
  background: none;
  border: none;
  font-size: 18px;
  cursor: pointer;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 12px;
}

@media (max-width: 1280px) {
  .graph-main-grid,
  .upload-grid,
  .qa-layout {
    grid-template-columns: 1fr;
  }
}