:root {
      --primary: #4361ee;
      --success: #06d6a0;
      --danger: #ef476f;
      --warning: #ffd166;
      --dark: #1a1a2e;
      --light: #f8f9fa;
      --gray: #6c757d;
      --border-radius: 8px;
      --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
      --transition: all 0.3s ease;
    }
    
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    
    body {
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      background: linear-gradient(135deg, #0f0c29, #302b63, #24243e);
      color: var(--light);
      line-height: 1.6;
      min-height: 100vh;
      padding: 20px;
    }
    
    .container {
      max-width: 1000px;
      margin: 0 auto;
      background: rgba(26, 26, 46, 0.9);
      border-radius: var(--border-radius);
      box-shadow: var(--box-shadow);
      overflow: hidden;
      backdrop-filter: blur(10px);
    }
    
    header {
      text-align: center;
      padding: 2rem;
      background: rgba(0, 0, 0, 0.2);
      border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    }
    
    h1 {
      font-size: 2.5rem;
      margin-bottom: 0.5rem;
      background: linear-gradient(90deg, #4361ee, #06d6a0);
      -webkit-background-clip: text;
      -webkit-text-fill-color: transparent;
    }
    
    .subtitle {
      color: #adb5bd;
      font-size: 1.1rem;
    }
    
    .tab-buttons {
      display: flex;
      position: relative;
      background: rgba(0, 0, 0, 0.2);
    }
    
    .tab-button {
      flex: 1;
      padding: 1rem;
      background: none;
      border: none;
      color: var(--light);
      font-size: 1.1rem;
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition);
      position: relative;
      z-index: 1;
    }
    
    .tab-button.active {
      color: var(--primary);
    }
    
    .tab-slider {
      position: absolute;
      bottom: 0;
      height: 4px;
      background: var(--primary);
      transition: var(--transition);
      width: 50%;
    }
    
    .tab-panel {
      display: none;
      padding: 2rem;
    }
    
    .tab-panel.active {
      display: block;
      animation: fadeIn 0.5s ease;
    }
    
    @keyframes fadeIn {
      from { opacity: 0; transform: translateY(10px); }
      to { opacity: 1; transform: translateY(0); }
    }
    
    .encryption-type, .scan-method-selector {
      display: flex;
      margin-bottom: 1.5rem;
      background: rgba(255, 255, 255, 0.05);
      border-radius: var(--border-radius);
      overflow: hidden;
    }
    
    .type-btn, .method-btn {
      flex: 1;
      padding: 0.75rem;
      text-align: center;
      cursor: pointer;
      transition: var(--transition);
    }
    
    .type-btn.active, .method-btn.active {
      background: var(--primary);
      color: white;
    }
    
    .form-group {
      margin-bottom: 1.5rem;
    }
    
    .form-label {
      display: block;
      margin-bottom: 0.5rem;
      font-weight: 600;
      color: #e9ecef;
    }
    
    .form-input {
      width: 100%;
      padding: 0.75rem 1rem;
      border: 1px solid rgba(255, 255, 255, 0.1);
      border-radius: var(--border-radius);
      background: rgba(0, 0, 0, 0.2);
      color: var(--light);
      font-size: 1rem;
      transition: var(--transition);
    }
    
    .form-input:focus {
      outline: none;
      border-color: var(--primary);
      box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.3);
    }
    
    .file-input-wrapper {
      position: relative;
      margin-bottom: 0.5rem;
    }
    
    .file-input-button {
      padding: 0.75rem 1rem;
      background: rgba(67, 97, 238, 0.2);
      border: 1px dashed var(--primary);
      border-radius: var(--border-radius);
      text-align: center;
      cursor: pointer;
      transition: var(--transition);
    }
    
    .file-input-button:hover {
      background: rgba(67, 97, 238, 0.3);
    }
    
    .file-input {
      position: absolute;
      top: 0;
      left: 0;
      width: 100%;
      height: 100%;
      opacity: 0;
      cursor: pointer;
    }
    
    .file-name {
      font-size: 0.9rem;
      color: #adb5bd;
    }
    
    .file-list {
      margin-top: 1rem;
      padding: 1rem;
      background: rgba(0, 0, 0, 0.2);
      border-radius: var(--border-radius);
      max-height: 200px;
      overflow-y: auto;
    }
    
    .file-list-item {
      display: flex;
      justify-content: space-between;
      padding: 0.5rem 0;
      border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }
    
    .file-list-item:last-child {
      border-bottom: none;
    }
    
    .helper-text {
      font-size: 0.85rem;
      color: #6c757d;
      margin-top: 0.5rem;
    }
    
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 0.75rem 1.5rem;
      border: none;
      border-radius: var(--border-radius);
      font-size: 1rem;
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition);
    }
    
    .btn i {
      margin-right: 0.5rem;
    }
    
    .btn-success {
      background: var(--success);
      color: white;
    }
    
    .btn-success:hover {
      background: #05c290;
      transform: translateY(-2px);
    }
    
    .btn-danger {
      background: var(--danger);
      color: white;
    }
    
    .btn-danger:hover {
      background: #e73666;
      transform: translateY(-2px);
    }
    
    .btn-primary {
      background: var(--primary);
      color: white;
    }
    
    .btn-primary:hover {
      background: #3251d4;
      transform: translateY(-2px);
    }
    
    .btn-block {
      width: 100%;
    }
    
    .method-content {
      display: none;
      margin-top: 1rem;
    }
    
    .method-content.active {
      display: block;
      animation: fadeIn 0.5s ease;
    }
    
    .input-group {
      display: flex;
    }
    
    .input-group .form-input {
      border-top-right-radius: 0;
      border-bottom-right-radius: 0;
    }
    
    .input-group .btn {
      border-top-left-radius: 0;
      border-bottom-left-radius: 0;
    }
    
    .scanner-container {
      margin-top: 1rem;
      border-radius: var(--border-radius);
      overflow: hidden;
    }
    
    .qr-reader {
      width: 100%;
      height: 300px;
      background: #000;
      position: relative;
    }
    
    .scan-result {
      padding: 1rem;
      background: rgba(0, 0, 0, 0.2);
      text-align: center;
      font-weight: 600;
    }
    
    .qr-preview {
      display: block;
      max-width: 200px;
      margin: 1rem auto;
      border-radius: var(--border-radius);
    }
    
    .notification {
      position: fixed;
      bottom: 20px;
      right: 20px;
      padding: 1rem 1.5rem;
      background: var(--success);
      color: white;
      border-radius: var(--border-radius);
      box-shadow: var(--box-shadow);
      transform: translateY(100px);
      opacity: 0;
      transition: var(--transition);
      z-index: 1000;
    }
    
    .notification.show {
      transform: translateY(0);
      opacity: 1;
    }
    
    .security-indicator {
      height: 4px;
      background: var(--gray);
      border-radius: 2px;
      margin-top: 0.5rem;
      overflow: hidden;
      position: relative;
    }
    
    .security-progress {
      height: 100%;
      width: 0;
      transition: var(--transition);
    }
    
    .password-strength {
      display: flex;
      justify-content: space-between;
      margin-top: 0.5rem;
      font-size: 0.8rem;
    }
    
    .expiration-display {
      margin-top: 0.5rem;
      font-size: 0.9rem;
      color: #adb5bd;
    }
    
    @media (max-width: 768px) {
      body {
        padding: 10px;
      }
      
      h1 {
        font-size: 2rem;
      }
      
      .tab-button {
        padding: 0.75rem;
        font-size: 1rem;
      }
      
      .tab-panel {
        padding: 1.5rem;
      }
      
      .input-group {
        flex-direction: column;
      }
      
      .input-group .form-input {
        border-radius: var(--border-radius);
        margin-bottom: 0.5rem;
      }
      
      .input-group .btn {
        border-radius: var(--border-radius);
      }
    }