:root {
      --primary-color: #4a6cf7;
      --secondary-color: #6c757d;
      --success-color: #28a745;
      --danger-color: #dc3545;
      --dark-color: #343a40;
      --light-color: #f8f9fa;
      --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;
      line-height: 1.6;
      color: #333;
      background-color: #f5f7ff;
      padding: 0;
    }

    .navbar {
      background-color: white;
      box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
      padding: 1rem 0;
      position: sticky;
      top: 0;
      z-index: 100;
    }

    .nav-container {
      display: flex;
      justify-content: space-between;
      align-items: center;
      max-width: 1200px;
      margin: 0 auto;
      padding: 0 20px;
    }

    .logo a {
      font-size: 1.5rem;
      font-weight: 700;
      color: var(--primary-color);
      text-decoration: none;
    }

    .nav-links {
      list-style: none;
      display: flex;
      gap: 20px;
    }

    .nav-links li a {
      color: var(--dark-color);
      text-decoration: none;
      font-weight: 500;
      transition: var(--transition);
    }

    .nav-links li a:hover {
      color: var(--primary-color);
    }

    .container {
      max-width: 1200px;
      margin: 2rem auto;
      padding: 0 20px;
    }

    .app-container {
      display: grid;
      grid-template-columns: 1fr 1fr;
      gap: 2rem;
      margin-bottom: 3rem;
    }

    @media (max-width: 768px) {
      .app-container {
        grid-template-columns: 1fr;
      }
    }

    .upload-section, .preview-section {
      background: white;
      border-radius: var(--border-radius);
      padding: 2rem;
      box-shadow: var(--box-shadow);
    }

    h1 {
      text-align: center;
      margin-bottom: 1.5rem;
      color: var(--dark-color);
      font-weight: 700;
    }

    h2 {
      margin-bottom: 1rem;
      color: var(--dark-color);
    }

    .upload-area {
      border: 2px dashed #d1d5db;
      border-radius: var(--border-radius);
      padding: 2rem;
      text-align: center;
      cursor: pointer;
      transition: var(--transition);
      margin-bottom: 1.5rem;
    }

    .upload-area:hover {
      border-color: var(--primary-color);
      background-color: #f8faff;
    }

    .upload-area i {
      font-size: 3rem;
      color: var(--secondary-color);
      margin-bottom: 1rem;
    }

    .upload-area p {
      margin-bottom: 1rem;
      color: var(--secondary-color);
    }

    .btn {
      display: inline-block;
      padding: 0.75rem 1.5rem;
      background-color: var(--primary-color);
      color: white;
      border: none;
      border-radius: var(--border-radius);
      font-size: 1rem;
      font-weight: 600;
      cursor: pointer;
      transition: var(--transition);
      text-align: center;
      text-decoration: none;
    }

    .btn:hover {
      background-color: #c6c6c7;
      transform: translateY(-2px);
    }

    .btn:disabled {
      background-color: var(--secondary-color);
      cursor: not-allowed;
      transform: none;
    }

    .btn-success {
      background-color: var(--success-color);
    }

    .btn-success:hover {
      background-color: #218838;
    }

    .btn-danger {
      background-color: var(--danger-color);
    }

    .btn-danger:hover {
      background-color: #c82333;
    }

    .controls {
      margin-top: 1.5rem;
    }

    .control-group {
      margin-bottom: 1rem;
    }

    .control-group label {
      display: block;
      margin-bottom: 0.5rem;
      font-weight: 500;
    }

    .control-group input[type="range"] {
      width: 100%;
    }

    .preview-container {
      display: flex;
      flex-direction: column;
      align-items: center;
      gap: 1rem;
    }

    .image-preview {
      max-width: 100%;
      max-height: 300px;
      border-radius: var(--border-radius);
      box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    }

    .file-info {
      background-color: #f8f9fa;
      padding: 1rem;
      border-radius: var(--border-radius);
      width: 100%;
    }

    .file-info p {
      margin-bottom: 0.5rem;
    }

    .download-options {
      display: flex;
      gap: 1rem;
      margin-top: 1.5rem;
      flex-wrap: wrap;
    }

    .content-section {
      background: white;
      border-radius: var(--border-radius);
      padding: 2rem;
      box-shadow: var(--box-shadow);
      margin-bottom: 2rem;
    }

    .content-section h2 {
      color: var(--primary-color);
      margin-bottom: 1rem;
    }

    .content-section p {
      margin-bottom: 1rem;
      line-height: 1.7;
    }

    .footer {
      background-color: var(--dark-color);
      color: white;
      text-align: center;
      padding: 1.5rem;
      margin-top: 3rem;
    }

    .format-badge {
      display: inline-block;
      padding: 0.25rem 0.75rem;
      background-color: var(#d19f32);
      color: rgb(255, 255, 255);
      border-radius: 20px;
      font-size: 0.875rem;
      margin-right: 0.5rem;
      margin-bottom: 0.5rem;
    }

    .quality-display {
      display: flex;
      justify-content: space-between;
      margin-top: 0.5rem;
    }

    .quality-value {
      font-weight: 600;
      color: var(--primary-color);
    }

    .compression-levels {
      display: flex;
      gap: 1rem;
      margin-bottom: 1rem;
    }

    .compression-option {
      flex: 1;
      text-align: center;
      padding: 0.75rem;
      border: 2px solid #d1d5db;
      border-radius: var(--border-radius);
      cursor: pointer;
      transition: var(--transition);
    }

    .compression-option:hover {
      border-color: var(--primary-color);
    }

    .compression-option.active {
      border-color: var(--primary-color);
      background-color: #f0f4ff;
    }

    .compression-option h4 {
      margin-bottom: 0.5rem;
    }

    .compression-option p {
      font-size: 0.875rem;
      color: var(--secondary-color);
    }

    /* Products Section */
    .products-section {
      margin-top: 3rem;
    }

    .products-grid {
      display: grid;
      grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
      gap: 2rem;
      margin-top: 1.5rem;
    }

    .product-card {
      background: white;
      border-radius: var(--border-radius);
      overflow: hidden;
      box-shadow: var(--box-shadow);
      transition: var(--transition);
    }

    .product-card:hover {
      transform: translateY(-5px);
      box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    }

    .product-image {
      width: 100%;
      height: 200px;
      object-fit: cover;
    }

    .product-info {
      padding: 1.5rem;
    }

    .product-info h3 {
      margin-bottom: 0.5rem;
      color: var(--dark-color);
    }

    .product-info p {
      margin-bottom: 1rem;
      color: var(--secondary-color);
    }

    .product-link {
      display: inline-block;
      padding: 0.5rem 1rem;
      background-color: var(--primary-color);
      color: white;
      text-decoration: none;
      border-radius: var(--border-radius);
      font-weight: 500;
      transition: var(--transition);
    }

    .product-link:hover {
      background-color: #3a5bd9;
    }

    .comparison-container {
      display: flex;
      gap: 1rem;
      margin-top: 1rem;
    }

    .comparison-box {
      flex: 1;
      text-align: center;
    }

    .comparison-image {
      max-width: 100%;
      max-height: 200px;
      border-radius: var(--border-radius);
      box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    }

    .comparison-label {
      margin-top: 0.5rem;
      font-weight: 600;
    }

    .original-size {
      color: var(--secondary-color);
    }

    .optimized-size {
      color: var(--success-color);
    }