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

    body {
      font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      min-height: 100vh;
      padding: 2rem;
    }

    .app {
      max-width: 900px;
      margin: 0 auto;
      background: rgba(255, 255, 255, 0.98);
      border-radius: 24px;
      box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
      overflow: hidden;
      backdrop-filter: blur(10px);
    }

    /* Tabs */
    .tabs {
      display: flex;
      gap: 0;
      background: #f8f9fa;
      border-bottom: 2px solid #e9ecef;
      padding: 0 1.5rem;
    }

    .tab {
      padding: 1rem 2rem;
      font-size: 0.95rem;
      font-weight: 600;
      cursor: pointer;
      background: transparent;
      border: none;
      color: #6c757d;
      transition: all 0.3s ease;
      position: relative;
    }

    .tab:hover {
      color: #667eea;
    }

    .tab.active {
      color: #667eea;
    }

    .tab.active::after {
      content: '';
      position: absolute;
      bottom: -2px;
      left: 0;
      right: 0;
      height: 2px;
      background: #667eea;
    }

    /* Panels */
    .panel {
      display: none;
      padding: 2rem;
      animation: fadeIn 0.4s ease;
    }

    .panel.active {
      display: block;
    }

    @keyframes fadeIn {
      from {
        opacity: 0;
        transform: translateY(10px);
      }
      to {
        opacity: 1;
        transform: translateY(0);
      }
    }

    /* Cards */
    .card {
      background: white;
      border-radius: 16px;
      padding: 1.5rem;
      margin-bottom: 1.5rem;
      box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }

    .card:hover {
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    }

    .section-title {
      font-size: 0.85rem;
      font-weight: 700;
      text-transform: uppercase;
      letter-spacing: 1px;
      color: #667eea;
      margin-bottom: 1rem;
    }

    /* Grids */
    .grid3 {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
      gap: 1rem;
      margin-bottom: 1rem;
    }

    .grid2 {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
      gap: 1rem;
      margin-bottom: 1rem;
    }

    /* Fields */
    .field {
      display: flex;
      flex-direction: column;
      gap: 0.5rem;
    }

    .field label {
      font-size: 0.85rem;
      font-weight: 600;
      color: #495057;
    }

    .field input,
    .field select,
    textarea {
      padding: 0.6rem 0.8rem;
      border: 2px solid #e9ecef;
      border-radius: 10px;
      font-size: 0.9rem;
      font-family: 'Courier New', monospace;
      transition: all 0.2s ease;
      background: white;
    }

    .field input:focus,
    .field select:focus,
    textarea:focus {
      outline: none;
      border-color: #667eea;
      box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
    }

    /* File area */
    .file-area {
      border: 2px dashed #dee2e6;
      border-radius: 12px;
      padding: 2rem;
      text-align: center;
      cursor: pointer;
      transition: all 0.3s ease;
      background: #f8f9fa;
    }

    .file-area:hover {
      border-color: #667eea;
      background: #f0f3ff;
      transform: translateY(-2px);
    }

    .file-area input {
      display: none;
    }

    .file-info {
      font-size: 0.85rem;
      color: #6c757d;
      margin-top: 0.5rem;
    }

    /* Buttons */
    .actions {
      display: flex;
      gap: 0.75rem;
      flex-wrap: wrap;
      margin-top: 1rem;
    }

    .btn {
      padding: 0.7rem 1.5rem;
      font-size: 0.9rem;
      font-weight: 600;
      cursor: pointer;
      border: none;
      border-radius: 12px;
      transition: all 0.2s ease;
      font-family: inherit;
    }

    .btn-primary {
      background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
      color: white;
      box-shadow: 0 2px 4px rgba(102, 126, 234, 0.3);
    }

    .btn-primary:hover {
      transform: translateY(-2px);
      box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
    }

    .btn-primary:active {
      transform: translateY(0);
    }

    .btn {
      background: #f8f9fa;
      color: #495057;
      border: 1px solid #dee2e6;
    }

    .btn:hover {
      background: #e9ecef;
      transform: translateY(-1px);
    }

    /* Results & Messages */
    .output-box {
      font-family: 'Courier New', monospace;
      font-size: 0.8rem;
      background: #f8f9fa;
      border-radius: 10px;
      padding: 1rem;
      max-height: 200px;
      overflow-y: auto;
      line-height: 1.6;
      margin-top: 0.5rem;
    }

    .msg {
      padding: 0.75rem 1rem;
      border-radius: 10px;
      font-size: 0.85rem;
      margin-top: 0.75rem;
      animation: slideIn 0.3s ease;
    }

    @keyframes slideIn {
      from {
        opacity: 0;
        transform: translateX(-10px);
      }
      to {
        opacity: 1;
        transform: translateX(0);
      }
    }

    .msg.ok {
      background: #d4edda;
      color: #155724;
      border-left: 4px solid #28a745;
    }

    .msg.err {
      background: #f8d7da;
      color: #721c24;
      border-left: 4px solid #dc3545;
    }

    .msg.info {
      background: #d1ecf1;
      color: #0c5460;
      border-left: 4px solid #17a2b8;
    }

    /* Step list */
    .step-list {
      list-style: none;
      padding: 0;
    }

    .step-list li {
      padding: 0.5rem 0;
      font-size: 0.85rem;
      color: #495057;
      border-bottom: 1px solid #f0f0f0;
    }

    .step-list li:last-child {
      border-bottom: none;
    }

    .step-list li span {
      font-family: 'Courier New', monospace;
      font-weight: 700;
      color: #667eea;
      background: #f0f3ff;
      padding: 0.2rem 0.4rem;
      border-radius: 6px;
      font-size: 0.8rem;
    }

    hr {
      margin: 1.5rem 0;
      border: none;
      border-top: 2px solid #f0f0f0;
    }

    .badge {
      display: inline-block;
      padding: 0.25rem 0.75rem;
      border-radius: 20px;
      font-size: 0.7rem;
      font-weight: 600;
    }

    .badge-ok {
      background: #d4edda;
      color: #155724;
    }

    .badge-err {
      background: #f8d7da;
      color: #721c24;
    }

    .result-row {
      display: flex;
      justify-content: space-between;
      align-items: center;
      padding: 0.5rem 0;
      border-bottom: 1px solid #f0f0f0;
    }

    .result-label {
      font-weight: 600;
      color: #6c757d;
      font-size: 0.85rem;
    }

    .result-val {
      font-family: 'Courier New', monospace;
      font-weight: 700;
      color: #667eea;
    }

    /* Responsive */
    @media (max-width: 640px) {
      body {
        padding: 1rem;
      }
      
      .panel {
        padding: 1.5rem;
      }
      
      .tabs {
        padding: 0 1rem;
      }
      
      .tab {
        padding: 0.75rem 1rem;
        font-size: 0.85rem;
      }
      
      .grid3, .grid2 {
        grid-template-columns: 1fr;
      }
    }
    
    /* Scrollbar styling */
    ::-webkit-scrollbar {
      width: 8px;
      height: 8px;
    }
    
    ::-webkit-scrollbar-track {
      background: #f1f1f1;
      border-radius: 10px;
    }
    
    ::-webkit-scrollbar-thumb {
      background: #cbd5e0;
      border-radius: 10px;
    }
    
    ::-webkit-scrollbar-thumb:hover {
      background: #a0aec0;
    }
    
    /* Loading animation */
    .loading {
      display: inline-block;
      width: 20px;
      height: 20px;
      border: 3px solid rgba(102, 126, 234, 0.3);
      border-radius: 50%;
      border-top-color: #667eea;
      animation: spin 0.6s linear infinite;
    }
    
    @keyframes spin {
      to { transform: rotate(360deg); }
    }