:root {
  --primary: #4f46e5;
  --primary-light: #818cf8;
  --primary-dark: #3730a3;
  --success: #10b981;
  --danger: #ef4444;
  --warning: #f59e0b;
  --info: #3b82f6;
  --bg: #f8fafc;
  --card-bg: #ffffff;
  --text: #1e293b;
  --text-light: #64748b;
  --border: #e2e8f0;
  --shadow: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-lg: 0 10px 30px rgba(0,0,0,0.1);
  --radius: 12px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

/* 顶部导航 */
.navbar {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: white;
  padding: 0 20px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow);
}

.navbar-brand {
  font-size: 20px;
  font-weight: 700;
  color: white;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.navbar-nav {
  display: flex;
  gap: 16px;
  align-items: center;
}

.navbar-nav a {
  color: rgba(255,255,255,0.9);
  text-decoration: none;
  font-size: 15px;
  display: flex;
  align-items: center;
  gap: 6px;
  transition: opacity 0.2s;
}

.navbar-nav a:hover {
  opacity: 0.8;
}

/* 容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
}

/* 搜索区域 */
.search-section {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 24px;
  margin-bottom: 24px;
  box-shadow: var(--shadow);
}

.search-bar {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
}

.search-bar input {
  flex: 1;
  padding: 12px 16px;
  border: 2px solid var(--border);
  border-radius: 8px;
  font-size: 16px;
  transition: border-color 0.2s;
}

.search-bar input:focus {
  outline: none;
  border-color: var(--primary);
}

.btn {
  padding: 12px 24px;
  border: none;
  border-radius: 8px;
  font-size: 15px;
  cursor: pointer;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  text-decoration: none;
  font-weight: 500;
}

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

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

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

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

.btn-outline {
  background: transparent;
  border: 2px solid var(--border);
  color: var(--text);
}

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

.btn-sm {
  padding: 6px 12px;
  font-size: 13px;
}

/* 分类筛选 */
.category-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.cat-chip {
  padding: 6px 16px;
  border-radius: 20px;
  background: var(--bg);
  color: var(--text-light);
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
  border: 1px solid var(--border);
}

.cat-chip:hover {
  border-color: var(--primary-light);
}

.cat-chip.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
}

/* 文档卡片网格 */
.doc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

.doc-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
  cursor: pointer;
}

.doc-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.doc-card-header {
  padding: 20px;
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.doc-icon {
  width: 48px;
  height: 48px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  color: var(--primary);
  background: rgba(79,70,229,0.1);
  flex-shrink: 0;
}

.doc-card-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.doc-card-desc {
  font-size: 13px;
  color: var(--text-light);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.doc-card-footer {
  padding: 12px 20px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  color: var(--text-light);
}

.doc-card-cat {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: var(--bg);
  padding: 2px 10px;
  border-radius: 12px;
  font-size: 12px;
}

/* 分页 */
.pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  margin-top: 32px;
}

.pagination button {
  padding: 8px 14px;
  border: 1px solid var(--border);
  background: white;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.2s;
}

.pagination button:hover:not(:disabled) {
  border-color: var(--primary);
  color: var(--primary);
}

.pagination button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.pagination .page-info {
  color: var(--text-light);
  font-size: 14px;
}

/* 表单 */
.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  margin-bottom: 6px;
  font-weight: 500;
  font-size: 14px;
}

.form-control {
  width: 100%;
  padding: 10px 14px;
  border: 2px solid var(--border);
  border-radius: 8px;
  font-size: 15px;
  transition: border-color 0.2s;
}

.form-control:focus {
  outline: none;
  border-color: var(--primary);
}

textarea.form-control {
  min-height: 100px;
  resize: vertical;
}

select.form-control {
  cursor: pointer;
}

/* 统计卡片 */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 24px;
}

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

.stat-icon {
  width: 50px;
  height: 50px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  color: white;
}

.stat-value {
  font-size: 24px;
  font-weight: 700;
}

.stat-label {
  font-size: 13px;
  color: var(--text-light);
}

/* 预览区域 */
.preview-container {
  background: var(--card-bg);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

.preview-header {
  padding: 16px 24px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.preview-body {
  padding: 24px;
  min-height: 400px;
}

.preview-body img {
  max-width: 100%;
  height: auto;
}

.preview-body iframe {
  width: 100%;
  min-height: 600px;
  border: none;
}

.preview-body pre {
  white-space: pre-wrap;
  word-break: break-all;
  font-family: "Fira Code", "Courier New", monospace;
  font-size: 14px;
  line-height: 1.8;
}

/* Toast 提示 */
.toast {
  position: fixed;
  top: 80px;
  right: 20px;
  padding: 12px 20px;
  border-radius: 8px;
  color: white;
  font-size: 14px;
  z-index: 9999;
  animation: slideIn 0.3s ease;
  box-shadow: var(--shadow-lg);
}

.toast.success { background: var(--success); }
.toast.error { background: var(--danger); }

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

/* 空状态 */
.empty-state {
  text-align: center;
  padding: 60px 20px;
  color: var(--text-light);
}

.empty-state i {
  font-size: 64px;
  margin-bottom: 16px;
  opacity: 0.3;
}

/* 表格 */
.table-container {
  background: var(--card-bg);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}

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

th, td {
  padding: 12px 16px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  font-size: 14px;
}

th {
  background: var(--bg);
  font-weight: 600;
  color: var(--text-light);
}

tr:hover td {
  background: rgba(79,70,229,0.02);
}

/* 登录页 */
.login-container {
  max-width: 400px;
  margin: 60px auto;
}

.login-card {
  background: var(--card-bg);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow-lg);
}

.login-title {
  text-align: center;
  margin-bottom: 30px;
  font-size: 24px;
  font-weight: 700;
}

/* 文件上传区 */
.upload-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 40px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
}

.upload-zone:hover, .upload-zone.dragover {
  border-color: var(--primary);
  background: rgba(79,70,229,0.03);
}

.upload-zone i {
  font-size: 48px;
  color: var(--primary);
  margin-bottom: 12px;
}

/* 响应式 */
@media (max-width: 768px) {
  .container { padding: 12px; }
  .navbar { padding: 0 12px; }
  .navbar-brand { font-size: 16px; }
  .navbar-nav a span { display: none; }
  .search-bar { flex-direction: column; }
  .doc-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .login-card { padding: 24px; }
  .table-container { overflow-x: auto; }
  th, td { white-space: nowrap; }
}

@media (max-width: 480px) {
  .stats-grid { grid-template-columns: 1fr; }
  .doc-card-header { padding: 14px; }
}