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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: #f5f7fa;
  color: #333;
}

.page {
  min-height: 100vh;
}

.hidden {
  display: none !important;
}

/* 登录页 */
#login-page {
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.login-box {
  background: white;
  padding: 40px;
  border-radius: 12px;
  box-shadow: 0 10px 40px rgba(0,0,0,0.2);
  text-align: center;
  width: 100%;
  max-width: 400px;
}

.login-box h1 {
  margin-bottom: 30px;
  color: #333;
}

.login-box input {
  width: 100%;
  padding: 14px;
  margin-bottom: 15px;
  border: 2px solid #e0e0e0;
  border-radius: 8px;
  font-size: 16px;
  transition: border-color 0.3s;
}

.login-box input:focus {
  outline: none;
  border-color: #667eea;
}

.login-box button {
  width: 100%;
  padding: 14px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}

.login-box button:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

/* 主页面布局 */
#main-page {
  display: flex;
  height: 100vh;
}

.sidebar {
  width: 260px;
  background: #2c3e50;
  color: white;
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}

.sidebar h2 {
  padding: 20px;
  font-size: 20px;
  border-bottom: 1px solid #34495e;
}

.menu {
  list-style: none;
  flex: 1;
  padding: 10px 0;
}

.menu-item {
  padding: 14px 20px;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 10px;
}

.menu-item:hover {
  background: #34495e;
}

.menu-item.active {
  background: #3498db;
}

.user-info {
  padding: 15px 20px;
  border-top: 1px solid #34495e;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.user-info button {
  padding: 6px 12px;
  background: #e74c3c;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

.content {
  flex: 1;
  overflow-y: auto;
  padding: 30px;
}

/* 页面元素 */
.page-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.page-header h1 {
  font-size: 28px;
}

.filters {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.filters input, .filters select {
  padding: 10px 14px;
  border: 2px solid #e0e0e0;
  border-radius: 6px;
  font-size: 14px;
}

.filters input:focus, .filters select:focus {
  outline: none;
  border-color: #3498db;
}

.btn {
  padding: 10px 20px;
  background: #ecf0f1;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
  transition: all 0.2s;
}

.btn:hover {
  background: #bdc3c7;
}

.btn.primary {
  background: #3498db;
  color: white;
}

.btn.primary:hover {
  background: #2980b9;
}

.btn.danger {
  background: #e74c3c;
  color: white;
}

.btn.danger:hover {
  background: #c0392b;
}

/* 统计卡片 */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin-bottom: 30px;
}

.stat-card {
  background: white;
  padding: 25px;
  border-radius: 10px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.stat-card h3 {
  color: #7f8c8d;
  font-size: 14px;
  margin-bottom: 10px;
}

.stat-number {
  font-size: 36px;
  font-weight: 700;
  color: #2c3e50;
}

.stat-card.warning .stat-number {
  color: #e67e22;
}

.stat-card.success .stat-number {
  color: #27ae60;
}

.stat-card.danger .stat-number {
  color: #e74c3c;
}

/* 表格 */
.table {
  width: 100%;
  background: white;
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  border-collapse: collapse;
}

.table th, .table td {
  padding: 14px 16px;
  text-align: left;
  border-bottom: 1px solid #ecf0f1;
}

.table th {
  background: #f8f9fa;
  font-weight: 600;
  color: #2c3e50;
}

.table tr:hover {
  background: #f8f9fa;
}

.table-actions {
  display: flex;
  gap: 8px;
}

.table-actions button {
  padding: 6px 12px;
  font-size: 12px;
}

/* 表单 */
.form {
  background: white;
  padding: 30px;
  border-radius: 10px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
}

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

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
  color: #2c3e50;
}

.form-group input, .form-group select, .form-group textarea {
  width: 100%;
  padding: 12px;
  border: 2px solid #e0e0e0;
  border-radius: 6px;
  font-size: 14px;
}

.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
  outline: none;
  border-color: #3498db;
}

.form-group textarea {
  min-height: 80px;
  resize: vertical;
}

.form-actions {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid #ecf0f1;
}

/* 标签页 */
.tabs {
  display: flex;
  gap: 5px;
  margin-bottom: 20px;
  border-bottom: 2px solid #ecf0f1;
}

.tab {
  padding: 12px 24px;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  color: #7f8c8d;
  border-bottom: 2px solid transparent;
  margin-bottom: -2px;
}

.tab.active {
  color: #3498db;
  border-bottom-color: #3498db;
}

/* 弹窗 */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0,0,0,0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
}

.modal-content {
  background: white;
  padding: 0;
  border-radius: 12px;
  width: 90%;
  max-width: 500px;
  max-height: 90vh;
  overflow-y: auto;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 25px;
  border-bottom: 1px solid #ecf0f1;
}

.modal-header h2 {
  font-size: 20px;
}

.modal-header .close {
  background: none;
  border: none;
  font-size: 28px;
  cursor: pointer;
  color: #7f8c8d;
}

.modal-content .form {
  box-shadow: none;
  padding: 25px;
}

/* 响应式 */
@media (max-width: 768px) {
  #main-page {
    flex-direction: column;
  }
  
  .sidebar {
    width: 100%;
    height: auto;
  }
  
  .menu {
    display: flex;
    overflow-x: auto;
  }
  
  .menu-item {
    white-space: nowrap;
  }
}