:root {
      --primary: #4361ee;
      --secondary: #3f37c9;
      --accent: #4895ef;
      --light: #f8f9fa;
      --dark: #212529;
      --success: #4cc9f0;
      --danger: #f72585;
      --warning: #f8961e;
      --info: #43aa8b;
    }
    
    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }
    
    body {
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      line-height: 1.6;
      color: var(--dark);
      background-color: #f5f7fa;
      padding: 0;
      margin: 0;
    }
    
    .container {
      max-width: 100%;
      padding: 0 15px;
      margin: 0 auto;
    }
    
    @media (min-width: 768px) {
      .container {
        max-width: 720px;
      }
    }
    
    @media (min-width: 992px) {
      .container {
        max-width: 960px;
      }
    }
    
    @media (min-width: 1200px) {
      .container {
        max-width: 1140px;
      }
    }
    
    header {
      background: linear-gradient(135deg, var(--primary), var(--secondary));
      color: white;
      padding: 1.5rem 0;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
      position: sticky;
      top: 0;
      z-index: 100;
    }
    
    .header-content {
      display: flex;
      justify-content: space-between;
      align-items: center;
    }
    
    .logo {
      font-size: 1.8rem;
      font-weight: 700;
      display: flex;
      align-items: center;
    }
    
    .logo i {
      margin-right: 0.5rem;
    }
    
    .stats {
      display: flex;
      gap: 1rem;
    }
    
    .stat-item {
      background: rgba(255, 255, 255, 0.2);
      padding: 0.5rem 1rem;
      border-radius: 50px;
      font-size: 0.9rem;
      display: flex;
      align-items: center;
    }
    
    .stat-item i {
      margin-right: 0.3rem;
    }
    
    .tabs {
      display: flex;
      border-bottom: 1px solid #dee2e6;
      margin-bottom: 1.5rem;
      overflow-x: auto;
      -webkit-overflow-scrolling: touch;
    }
    
    .tab {
      padding: 0.75rem 1.5rem;
      cursor: pointer;
      border-bottom: 3px solid transparent;
      font-weight: 500;
      white-space: nowrap;
      transition: all 0.3s ease;
    }
    
    .tab:hover {
      color: var(--primary);
    }
    
    .tab.active {
      color: var(--primary);
      border-bottom-color: var(--primary);
    }
    
    .tab-content {
      display: none;
      animation: fadeIn 0.3s ease;
    }
    
    .tab-content.active {
      display: block;
    }
    
    .card-form {
      background: white;
      border-radius: 10px;
      padding: 1.5rem;
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
      margin-bottom: 2rem;
    }
    
    .form-group {
      margin-bottom: 1.25rem;
    }
    
    .form-label {
      display: block;
      margin-bottom: 0.5rem;
      font-weight: 500;
    }
    
    .form-control {
      width: 100%;
      padding: 0.75rem;
      border: 1px solid #ced4da;
      border-radius: 6px;
      font-size: 1rem;
      transition: border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
    }
    
    .form-control:focus {
      border-color: var(--accent);
      outline: 0;
      box-shadow: 0 0 0 0.2rem rgba(67, 97, 238, 0.25);
    }
    
    textarea.form-control {
      min-height: 100px;
      resize: vertical;
    }
    
    .image-upload {
      display: flex;
      flex-direction: column;
      gap: 0.5rem;
    }
    
    .image-preview-container {
      display: flex;
      gap: 1rem;
      flex-wrap: wrap;
    }
    
    .image-preview {
      width: 100px;
      height: 100px;
      object-fit: cover;
      border-radius: 6px;
      border: 1px solid #dee2e6;
      display: none;
    }
    
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      font-weight: 500;
      text-align: center;
      white-space: nowrap;
      vertical-align: middle;
      user-select: none;
      border: 1px solid transparent;
      padding: 0.75rem 1.5rem;
      font-size: 1rem;
      line-height: 1.5;
      border-radius: 6px;
      transition: all 0.15s ease-in-out;
      cursor: pointer;
    }
    
    .btn i {
      margin-right: 0.5rem;
    }
    
    .btn-primary {
      color: white;
      background-color: var(--primary);
    }
    
    .btn-primary:hover {
      background-color: var(--secondary);
    }
    
    .btn-success {
      color: white;
      background-color: var(--success);
    }
    
    .btn-success:hover {
      background-color: #3aa8d4;
    }
    
    .btn-danger {
      color: white;
      background-color: var(--danger);
    }
    
    .btn-danger:hover {
      background-color: #e5177b;
    }
    
    .btn-block {
      display: block;
      width: 100%;
    }
    
    .card-viewer {
      background: white;
      border-radius: 10px;
      padding: 2rem;
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
      margin-bottom: 2rem;
      min-height: 300px;
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      position: relative;
      overflow: hidden;
    }
    
    .card-content {
      width: 100%;
      text-align: center;
      transition: transform 0.6s;
      transform-style: preserve-3d;
      position: relative;
    }
    
    .card-text {
      font-size: 1.5rem;
      margin-bottom: 1rem;
      word-break: break-word;
      backface-visibility: hidden;
    }
    
    .card-image {
      max-width: 100%;
      max-height: 250px;
      border-radius: 6px;
      margin: 0 auto 1rem;
      display: block;
      backface-visibility: hidden;
    }
    
    .card-controls {
      display: flex;
      gap: 1rem;
      margin-top: 1.5rem;
      width: 100%;
    }
    
    .card-controls .btn {
      flex: 1;
    }
    
    .progress-container {
      background: white;
      border-radius: 10px;
      padding: 1.5rem;
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
      margin-bottom: 2rem;
    }
    
    .progress-info {
      display: flex;
      justify-content: space-between;
      margin-bottom: 0.5rem;
    }
    
    .progress-bar {
      height: 10px;
      background-color: #e9ecef;
      border-radius: 5px;
      overflow: hidden;
    }
    
    .progress-bar-fill {
      height: 100%;
      background: linear-gradient(90deg, var(--primary), var(--accent));
      transition: width 0.3s ease;
    }
    
    .import-export {
      display: grid;
      gap: 1.5rem;
      grid-template-columns: 1fr;
    }
    
    @media (min-width: 768px) {
      .import-export {
        grid-template-columns: 1fr 1fr;
      }
    }
    
    .import-box, .export-box {
      background: white;
      border-radius: 10px;
      padding: 1.5rem;
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    }
    
    .section-title {
      font-size: 1.25rem;
      margin-bottom: 1rem;
      color: var(--dark);
      display: flex;
      align-items: center;
    }
    
    .section-title i {
      margin-right: 0.75rem;
      color: var(--primary);
    }
    
    .empty-state {
      text-align: center;
      padding: 3rem 1rem;
      color: #6c757d;
    }
    
    .empty-state i {
      font-size: 3rem;
      color: #adb5bd;
      margin-bottom: 1rem;
    }
    
    .empty-state h3 {
      margin-bottom: 0.5rem;
      color: #495057;
    }
    
    .badge {
      display: inline-block;
      padding: 0.35em 0.65em;
      font-size: 0.75em;
      font-weight: 700;
      line-height: 1;
      color: white;
      text-align: center;
      white-space: nowrap;
      vertical-align: baseline;
      border-radius: 50px;
      background-color: var(--primary);
    }
    
    .floating-action-btn {
      position: fixed;
      bottom: 2rem;
      right: 2rem;
      width: 60px;
      height: 60px;
      border-radius: 50%;
      background-color: var(--primary);
      color: white;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
      cursor: pointer;
      z-index: 99;
      transition: all 0.3s ease;
    }
    
    .floating-action-btn:hover {
      transform: translateY(-3px);
      box-shadow: 0 6px 16px rgba(0, 0, 0, 0.2);
    }
    
    @keyframes fadeIn {
      from { opacity: 0; }
      to { opacity: 1; }
    }
    
    @keyframes pulse {
      0% { transform: scale(1); }
      50% { transform: scale(1.05); }
      100% { transform: scale(1); }
    }
    
    .pulse {
      animation: pulse 1.5s infinite;
    }
    
    /* Flip animation */
    .flip-card {
      transform: rotateY(180deg);
    }
    
    /* Toast notifications */
    .toast {
      position: fixed;
      bottom: 20px;
      left: 50%;
      transform: translateX(-50%);
      background-color: var(--dark);
      color: white;
      padding: 12px 24px;
      border-radius: 4px;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
      z-index: 999;
      display: flex;
      align-items: center;
      opacity: 0;
      transition: opacity 0.3s ease;
    }
    
    .toast.show {
      opacity: 1;
    }
    
    .toast i {
      margin-right: 8px;
    }

    /* Footer styles */
    .footer {
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      background-color: #f8f9fa;
      padding: 30px 0;
      text-align: center;
      border-top: 1px solid #e1e1e1;
      margin-top: 40px;
    }
    
    .footer-name {
      font-size: 1.5rem;
      font-weight: 600;
      color: #2c3e50;
      margin-bottom: 5px;
    }
    
    .footer-title {
      font-size: 1rem;
      color: #7f8c8d;
      margin-bottom: 20px;
      font-weight: 400;
    }
    
    .footer-links {
      display: flex;
      justify-content: center;
      gap: 25px;
      margin-bottom: 20px;
      flex-wrap: wrap;
    }
    
    .footer-link {
      display: flex;
      align-items: center;
      color: #3498db;
      text-decoration: none;
      transition: color 0.3s;
    }
    
    .footer-link:hover {
      color: #2980b9;
    }
    
    .footer-link i {
      margin-right: 8px;
      font-size: 1.1rem;
    }
    
    .footer-quote {
      font-style: italic;
      color: #555;
      max-width: 600px;
      margin: 0 auto;
      padding: 0 20px;
      line-height: 1.5;
    }
    
    /* Button styles */
    .btn-secondary {
      color: white;
      background-color: #6c757d;
      border-color: #6c757d;
    }
    .btn-secondary:hover {
      background-color: #5a6268;
      border-color: #545b62;
    }
    
    .progress-info span {
      margin-right: 15px;
    }
    
    /* Responsive adjustments */
    @media (max-width: 576px) {
      .header-content {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
      }
      
      .stats {
        width: 100%;
        justify-content: space-between;
      }
      
      .card-controls {
        flex-direction: column;
      }
      
      .floating-action-btn {
        bottom: 1rem;
        right: 1rem;
        width: 50px;
        height: 50px;
      }
      
      @media (max-width: 600px) {
        .footer-links {
          flex-direction: column;
          gap: 10px;
          padding-left: 2.3125rem;
        }
      }
    }