:root {
    --text-color: #37352f;
    --background-color: #ffffff;
    --sidebar-bg: #f7f6f3;
    --hover-color: #efefef;
    --border-color: #e0e0e0;
    --accent-color: #2eaadc;
    --shadow: 0 1px 3px rgba(0,0,0,0.12);
    --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  }
  
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font-family: var(--font-family);
    color: var(--text-color);
    background-color: var(--background-color);
    display: flex;
    height: 100vh;
    overflow: hidden;
  }
  
  .sidebar {
    width: 250px;
    background-color: var(--sidebar-bg);
    height: 100%;
    border-right: 1px solid var(--border-color);
    overflow-y: auto;
    flex-shrink: 0;
    padding: 16px 0;
    transition: all 0.3s ease;
  }
  
  .sidebar-item {
    padding: 8px 16px;
    display: flex;
    align-items: center;
    cursor: pointer;
    transition: background-color 0.2s;
    border-radius: 3px;
    margin: 2px 8px;
  }
  
  .sidebar-item:hover {
    background-color: var(--hover-color);
  }
  
  .sidebar-item.active {
    background-color: rgba(46, 170, 220, 0.1);
    font-weight: 500;
  }
  
  .sidebar-item svg {
    margin-right: 8px;
    flex-shrink: 0;
  }
  
  .sidebar-section {
    margin-bottom: 16px;
  }
  
  .sidebar-section-title {
    padding: 6px 16px;
    font-size: 12px;
    text-transform: uppercase;
    color: rgba(55, 53, 47, 0.6);
    letter-spacing: 0.5px;
    margin-top: 10px;
  }
  
  .nested-items {
    padding-left: 12px;
  }
  
  .main-content {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
  }
  
  .page-title {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 20px;
    padding-bottom: 4px;
  }
  
  .content-card {
    background-color: var(--background-color);
    border-radius: 4px;
    box-shadow: var(--shadow);
    padding: 24px;
    margin-bottom: 24px;
    border: 1px solid var(--border-color);
  }
  
  .card-title {
    font-size: 18px;
    font-weight: 500;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
  }
  
  .form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 16px;
  }
  
  .form-group {
    margin-bottom: 16px;
  }
  
  .form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    color: rgba(55, 53, 47, 0.7);
  }
  
  .form-control {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: 3px;
    font-family: inherit;
    font-size: 14px;
    background-color: transparent;
    transition: border-color 0.2s;
  }
  
  .form-control:focus {
    border-color: var(--accent-color);
    outline: none;
  }
  
  .button-group {
    display: flex;
    gap: 12px;
    margin-top: 24px;
    justify-content: flex-end;
  }
  
  .btn {
    padding: 8px 14px;
    border-radius: 3px;
    font-size: 14px;
    cursor: pointer;
    transition: background-color 0.2s;
    border: none;
    font-weight: 500;
  }
  
  .btn-primary {
    background-color: var(--accent-color);
    color: white;
  }
  
  .btn-primary:hover {
    background-color: #2399c9;
  }
  
  .btn-secondary {
    background-color: var(--hover-color);
    color: var(--text-color);
  }
  
  .btn-secondary:hover {
    background-color: #e0e0e0;
  }
  
  table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 16px;
    font-size: 14px;
  }
  
  thead {
    background-color: var(--sidebar-bg);
  }
  
  th, td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
  }
  
  th {
    font-weight: 500;
    color: rgba(55, 53, 47, 0.7);
  }
  
  tr:hover {
    background-color: var(--hover-color);
  }
  
  .action-btn {
    padding: 4px 8px;
    border-radius: 3px;
    background-color: transparent;
    border: 1px solid var(--border-color);
    cursor: pointer;
    margin-right: 4px;
  }
  
  .action-btn:hover {
    background-color: var(--hover-color);
  }
  
  .add-btn {
    display: inline-flex;
    align-items: center;
    margin-bottom: 16px;
    background-color: transparent;
    border: none;
    cursor: pointer;
    color: var(--text-color);
    font-size: 14px;
    font-weight: 500;
    padding: 6px 10px;
    border-radius: 3px;
  }
  
  .add-btn:hover {
    background-color: var(--hover-color);
  }
  
  .add-btn svg {
    margin-right: 6px;
  }
  
  .tab-navigation {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 16px;
  }
  
  .tab {
    padding: 8px 16px;
    cursor: pointer;
    position: relative;
    color: rgba(55, 53, 47, 0.7);
  }
  
  .tab.active {
    color: var(--text-color);
    font-weight: 500;
  }
  
  .tab.active:after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--accent-color);
  }
  
  /* Responsive styles */
  @media (max-width: 768px) {
    .sidebar {
      width: 60px;
      overflow: hidden;
    }
    
    .sidebar-item span {
      display: none;
    }
    
    .sidebar-item svg {
      margin-right: 0;
    }
    
    .sidebar-section-title {
      display: none;
    }
    
    .form-grid {
      grid-template-columns: 1fr;
    }
    
    .table-responsive {
      overflow-x: auto;
    }
    
    table {
      min-width: 800px;
    }
  }
  
  @media (max-width: 480px) {
    .button-group {
      flex-direction: column;
    }
    
    .page-title {
      font-size: 28px;
    }
  }