:root {
  --primary: #1677ff;
  --primary-hover: #4096ff;
  --primary-active: #0958d9;
  --primary-bg: #e6f4ff;
  --success: #52c41a;
  --success-bg: #f6ffed;
  --warning: #faad14;
  --warning-bg: #fff7e6;
  --error: #ff4d4f;
  --error-bg: #fff1f0;
  --text-primary: #1f1f1f;
  --text-secondary: #666;
  --text-tertiary: #999;
  --bg-page: #f5f7fa;
  --bg-white: #ffffff;
  --border-color: #e8e8e8;
  --shadow-sm: 0 1px 4px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 2px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 4px 24px rgba(0, 0, 0, 0.12);
  --radius: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --sidebar-width: 240px;
  --header-height: 56px;
  --transition: all 0.2s ease;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  color: var(--text-primary);
  background: var(--bg-page);
  line-height: 1.6;
  font-size: 14px;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: var(--transition);
}

a:hover {
  color: var(--primary-hover);
}

/* ===== Layout ===== */
.app-layout {
  display: flex;
  min-height: 100vh;
}

.sidebar {
  width: var(--sidebar-width);
  background: var(--bg-white);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 100;
  transition: var(--transition);
}

.sidebar-header {
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  gap: 12px;
}

.sidebar-logo {
  width: 36px;
  height: 36px;
  background: var(--primary);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 18px;
  font-weight: 700;
  flex-shrink: 0;
}

.sidebar-brand {
  overflow: hidden;
}

.sidebar-brand h1 {
  font-size: 15px;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar-brand .portal-tag {
  font-size: 11px;
  color: var(--text-tertiary);
}

.sidebar-nav {
  flex: 1;
  padding: 12px 0;
  overflow-y: auto;
}

.nav-group {
  margin-bottom: 4px;
}

.nav-group-label {
  padding: 8px 20px 4px;
  font-size: 11px;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 1px;
  font-weight: 600;
}

.nav-link {
  display: flex;
  align-items: center;
  padding: 10px 20px;
  cursor: pointer;
  transition: var(--transition);
  font-size: 14px;
  color: var(--text-secondary);
  gap: 10px;
  border-left: 3px solid transparent;
  text-decoration: none;
}

.nav-link:hover {
  background: var(--bg-page);
  color: var(--text-primary);
  text-decoration: none;
}

.nav-link.active {
  background: var(--primary-bg);
  color: var(--primary);
  border-left-color: var(--primary);
  font-weight: 500;
}

.nav-link .nav-icon {
  font-size: 18px;
  width: 24px;
  text-align: center;
  flex-shrink: 0;
}

.nav-link .nav-badge {
  margin-left: auto;
  background: var(--error);
  color: white;
  font-size: 11px;
  min-width: 18px;
  height: 18px;
  border-radius: 9px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 5px;
}

.main-wrapper {
  flex: 1;
  margin-left: var(--sidebar-width);
  min-height: 100vh;
}

.top-header {
  height: var(--header-height);
  background: var(--bg-white);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  position: sticky;
  top: 0;
  z-index: 50;
}

.top-header h2 {
  font-size: 16px;
  font-weight: 600;
}

.top-header .header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.page-content {
  padding: 24px;
}

/* ===== Cards ===== */
.card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 20px;
  margin-bottom: 16px;
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-md);
}

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

.card-title {
  font-size: 15px;
  font-weight: 600;
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 8px 16px;
  border-radius: var(--radius);
  font-size: 14px;
  cursor: pointer;
  border: 1px solid transparent;
  transition: var(--transition);
  font-weight: 500;
  gap: 6px;
  white-space: nowrap;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

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

.btn-success {
  background: var(--success);
  color: white;
  border-color: var(--success);
}

.btn-success:hover {
  opacity: 0.85;
  color: white;
}

.btn-warning {
  background: var(--warning);
  color: white;
  border-color: var(--warning);
}

.btn-error {
  background: var(--error);
  color: white;
  border-color: var(--error);
}

.btn-error:hover {
  opacity: 0.85;
  color: white;
}

.btn-outline {
  background: transparent;
  border-color: var(--border-color);
  color: var(--text-primary);
}

.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: none;
}

.btn-ghost:hover {
  background: var(--bg-page);
  color: var(--text-primary);
}

.btn-sm {
  padding: 4px 12px;
  font-size: 12px;
}

.btn-lg {
  padding: 12px 24px;
  font-size: 16px;
}

.btn-icon {
  padding: 8px;
  min-width: 36px;
}

/* ===== Forms ===== */
.form-group {
  margin-bottom: 16px;
}

.form-label {
  display: block;
  font-size: 13px;
  font-weight: 500;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.form-label .required {
  color: var(--error);
  margin-left: 2px;
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: 8px 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  font-size: 14px;
  transition: var(--transition);
  background: var(--bg-white);
  color: var(--text-primary);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(22, 119, 255, 0.1);
}

.form-textarea {
  min-height: 100px;
  resize: vertical;
  font-family: inherit;
}

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

.form-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

/* ===== Table ===== */
.table-container {
  overflow-x: auto;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
}

table {
  width: 100%;
  border-collapse: collapse;
}

th, td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
  font-size: 13px;
}

th {
  background: var(--bg-page);
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  white-space: nowrap;
}

tbody tr {
  transition: var(--transition);
}

tbody tr:hover {
  background: #fafafa;
}

tbody tr:last-child td {
  border-bottom: none;
}

/* ===== Tags ===== */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 500;
  white-space: nowrap;
}

.tag-pending { background: var(--warning-bg); color: #d48806; }
.tag-design { background: var(--primary-bg); color: #0958d9; }
.tag-solution { background: #f0f0ff; color: #531dab; }
.tag-developing { background: #e6fffb; color: #08979c; }
.tag-done { background: var(--success-bg); color: #389e0d; }
.tag-rejected { background: var(--error-bg); color: #cf1322; }

/* ===== Grid ===== */
.grid {
  display: grid;
  gap: 16px;
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ===== Stats ===== */
.stats-row {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  display: flex;
  align-items: center;
  gap: 16px;
}

.stat-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  flex-shrink: 0;
}

.stat-icon.blue { background: var(--primary-bg); }
.stat-icon.green { background: var(--success-bg); }
.stat-icon.orange { background: var(--warning-bg); }
.stat-icon.red { background: var(--error-bg); }

.stat-info h3 {
  font-size: 24px;
  font-weight: 700;
  line-height: 1.2;
}

.stat-info p {
  font-size: 13px;
  color: var(--text-tertiary);
}

/* ===== Modal ===== */
.modal-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 1000;
  justify-content: center;
  align-items: center;
  animation: fadeIn 0.2s ease;
}

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

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from { transform: translateY(20px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

.modal {
  background: var(--bg-white);
  border-radius: var(--radius-xl);
  width: 90%;
  max-width: 800px;
  max-height: 85vh;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  animation: slideUp 0.3s ease;
  display: flex;
  flex-direction: column;
}

.modal-header {
  padding: 20px 24px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h3 {
  font-size: 16px;
  font-weight: 600;
}

.modal-close {
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
  color: var(--text-tertiary);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  transition: var(--transition);
}

.modal-close:hover {
  background: var(--bg-page);
  color: var(--text-primary);
}

.modal-body {
  padding: 24px;
  overflow-y: auto;
  flex: 1;
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: flex-end;
  gap: 8px;
}

/* ===== Steps ===== */
.steps {
  display: flex;
  margin-bottom: 24px;
  position: relative;
}

.step {
  flex: 1;
  text-align: center;
  position: relative;
}

.step::before {
  content: '';
  position: absolute;
  top: 16px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--border-color);
  z-index: 0;
}

.step:first-child::before { left: 50%; }
.step:last-child::before { right: 50%; }

.step-number {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--border-color);
  color: var(--text-tertiary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  font-weight: 600;
  position: relative;
  z-index: 1;
  transition: var(--transition);
}

.step.active .step-number {
  background: var(--primary);
  color: white;
}

.step.done .step-number {
  background: var(--success);
  color: white;
}

.step-title {
  font-size: 12px;
  margin-top: 8px;
  color: var(--text-tertiary);
}

.step.active .step-title {
  color: var(--primary);
  font-weight: 500;
}

.step.done .step-title {
  color: var(--success);
}

/* ===== Empty State ===== */
.empty-state {
  text-align: center;
  padding: 48px 20px;
  color: var(--text-tertiary);
}

.empty-state .empty-icon {
  font-size: 48px;
  margin-bottom: 16px;
  opacity: 0.5;
}

.empty-state h4 {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.empty-state p {
  font-size: 14px;
}

/* ===== Tabs ===== */
.tabs {
  display: flex;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: 20px;
  gap: 4px;
}

.tab {
  padding: 10px 20px;
  cursor: pointer;
  font-size: 14px;
  color: var(--text-secondary);
  border-bottom: 2px solid transparent;
  transition: var(--transition);
  font-weight: 500;
}

.tab:hover {
  color: var(--text-primary);
}

.tab.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

/* ===== Search ===== */
.search-box {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
}

.search-box input {
  flex: 1;
}

/* ===== Content Cards ===== */
.content-card {
  background: var(--bg-white);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
  cursor: pointer;
}

.content-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.content-card h4 {
  font-size: 15px;
  margin-bottom: 8px;
  line-height: 1.4;
}

.content-card p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.content-card .card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border-color);
  font-size: 12px;
  color: var(--text-tertiary);
}

/* ===== Feature Cards (Recent Features) ===== */
.features-timeline {
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-height: 70vh;
  overflow-y: auto;
  padding-right: 8px;
}

.feature-card {
  padding: 16px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  transition: var(--transition);
  cursor: pointer;
  background: var(--bg-white);
}

.feature-card:hover {
  border-color: var(--primary);
  background: #fafcff;
}

.feature-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 8px;
}

.feature-header h4 {
  font-size: 14px;
  font-weight: 600;
  line-height: 1.4;
}

.feature-card p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 8px;
}

.feature-meta {
  display: flex;
  gap: 16px;
  font-size: 12px;
  color: var(--text-tertiary);
}

.feature-meta span {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ===== Knowledge Items ===== */
.kb-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.kb-item {
  padding: 16px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  transition: var(--transition);
  cursor: pointer;
}

.kb-item:hover {
  border-color: var(--primary);
  background: #fafcff;
}

.kb-item h4 {
  font-size: 14px;
  margin-bottom: 6px;
}

.kb-item p {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ===== Detail View ===== */
.detail-section {
  margin-bottom: 20px;
}

.detail-label {
  font-size: 12px;
  color: var(--text-tertiary);
  margin-bottom: 4px;
}

.detail-value {
  font-size: 14px;
  color: var(--text-primary);
  line-height: 1.6;
}

.detail-value p {
  white-space: pre-wrap;
}

/* ===== Toast ===== */
.toast-container {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 2000;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.toast {
  padding: 12px 20px;
  border-radius: var(--radius);
  background: var(--bg-white);
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  animation: slideIn 0.3s ease;
  min-width: 280px;
}

.toast.success { border-left: 4px solid var(--success); }
.toast.error { border-left: 4px solid var(--error); }
.toast.info { border-left: 4px solid var(--primary); }

@keyframes slideIn {
  from { transform: translateX(100%); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}

/* ===== Document Cards (Knowledge Base) ===== */
.doc-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}

.doc-card {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.doc-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.doc-card-icon {
  font-size: 40px;
  margin-bottom: 12px;
  width: 64px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-page);
  border-radius: var(--radius-lg);
}

.doc-card-body h4 {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.doc-card-body p {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* ===== Q&A Section ===== */
.qa-section {
  border: 1px solid var(--primary);
  background: linear-gradient(135deg, #f0f7ff 0%, #ffffff 100%);
}

.qa-header {
  text-align: center;
  margin-bottom: 16px;
}

.qa-header h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 4px;
}

.qa-header p {
  font-size: 13px;
  color: var(--text-secondary);
}

.qa-input-row {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
}

.qa-input {
  flex: 1;
}

.qa-history {
  max-height: 400px;
  overflow-y: auto;
  padding: 8px 0;
}

.qa-empty {
  text-align: center;
  color: var(--text-tertiary);
  font-size: 13px;
  padding: 24px 0;
}

.qa-msg {
  display: flex;
  gap: 10px;
  margin-bottom: 12px;
  align-items: flex-start;
}

.qa-msg-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  flex-shrink: 0;
}

.qa-user .qa-msg-avatar {
  background: var(--primary-bg);
}

.qa-ai .qa-msg-avatar {
  background: #f0f0ff;
}

.qa-msg-bubble {
  padding: 10px 14px;
  border-radius: 12px;
  font-size: 13px;
  line-height: 1.6;
  max-width: 80%;
}

.qa-user .qa-msg-bubble {
  background: var(--primary);
  color: white;
  border-bottom-left-radius: 4px;
}

.qa-ai .qa-msg-bubble {
  background: var(--bg-white);
  border: 1px solid var(--border-color);
  border-bottom-right-radius: 4px;
}

/* ===== Full Document View ===== */
.doc-full-content {
  font-size: 13px;
  line-height: 1.8;
}

.doc-full-content h2 {
  font-size: 20px;
  font-weight: 700;
  margin: 24px 0 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.doc-full-content h3 {
  font-size: 17px;
  font-weight: 600;
  margin: 20px 0 10px;
}

.doc-full-content h4 {
  font-size: 15px;
  font-weight: 600;
  margin: 16px 0 8px;
}

.doc-full-content strong {
  font-weight: 600;
}

.doc-full-content img {
  max-width: 100%;
  border-radius: 8px;
  margin: 8px 0;
}

.doc-full-content a {
  color: var(--primary);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .stats-row { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .doc-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .sidebar {
    width: 64px;
  }
  
  .sidebar-brand,
  .nav-group-label,
  .nav-link span:not(.nav-icon):not(.nav-badge) {
    display: none;
  }
  
  .nav-link {
    justify-content: center;
    padding: 12px;
  }
  
  .nav-link .nav-icon {
    margin: 0;
  }
  
  .nav-link .nav-badge {
    position: absolute;
    top: 4px;
    right: 4px;
    min-width: 16px;
    height: 16px;
    font-size: 10px;
  }
  
  .main-wrapper {
    margin-left: 64px;
  }
  
  .stats-row { grid-template-columns: 1fr; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .page-content { padding: 16px; }
}