* {
    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: #f8f9fa;
  }
  
  .container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
  }
  
  h1,
  h2,
  h3,
  h4,
  h5,
  h6 {
    margin-bottom: 0.5em;
    font-weight: 600;
    line-height: 1.3;
  }
  
  h1 {
    font-size: 2.5rem;
  }
  
  h2 {
    font-size: 2rem;
  }
  
  h3 {
    font-size: 1.5rem;
  }
  
  p {
    margin-bottom: 1rem;
  }
  
  a {
    color: #0066cc;
    text-decoration: none;
    transition: color 0.3s;
  }
  
  a:hover {
    color: #004499;
  }
  
  header {
    background-color: #fff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
  }
  
  header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
  }
  
  .logo h1 {
    font-size: 1.5rem;
    margin: 0;
    color: #0066cc;
  }
  
  nav ul {
    display: flex;
    list-style: none;
  }
  
  nav ul li {
    margin-left: 1.5rem;
  }
  
  nav ul li a {
    color: #333;
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
  }
  
  nav ul li a:after {
    content: "";
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: #0066cc;
    transition: width 0.3s;
  }
  
  nav ul li a:hover:after {
    width: 100%;
  }
  
  .menu-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
  }
  
  main {
    min-height: calc(100vh - 150px);
    padding: 2rem 0;
  }
  
  .hero {
    background-color: #0066cc;
    color: white;
    padding: 4rem 0;
    text-align: center;
    margin-bottom: 2rem;
    border-radius: 0.5rem;
  }
  
  .hero h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
  }
  
  .hero p {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto 2rem;
  }
  
  .cta-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
  }
  
  .btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 0.25rem;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
    border: none;
  }
  
  .btn-primary {
    background-color: #fff;
    color: #0066cc;
  }
  
  .btn-primary:hover {
    background-color: #f0f0f0;
    color: #004499;
  }
  
  .btn-secondary {
    background-color: transparent;
    color: #fff;
    border: 1px solid #fff;
  }
  
  .btn-secondary:hover {
    background-color: rgba(235, 228, 228, 0.61);
  }
  
  .products {
    padding: 3rem 0;
  }
  
  .products h2 {
    text-align: center;
    margin-bottom: 0.5rem;
  }
  
  .products > p {
    text-align: center;
    margin-bottom: 2rem;
    color: #666;
  }
  
  .product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 2rem;
  }
  
  .product-card {
    background-color: #fff;
    border-radius: 0.5rem;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
  }
  
  .product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px rgba(0, 0, 0, 0.1);
  }
  
  .product-card img {
    width: 100%;
    height: 180px;
    object-fit: cover;
  }
  
  .product-card h3 {
    padding: 1rem;
    text-align: center;
    font-size: 1.2rem;
  }
  
  .features {
    background-color: #f0f5ff;
    padding: 3rem 0;
    margin-top: 2rem;
    border-radius: 0.5rem;
  }
  
  .features h2 {
    text-align: center;
    margin-bottom: 2rem;
  }
  
  .feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
  }
  
  .feature-card {
    background-color: #fff;
    padding: 2rem;
    border-radius: 0.5rem;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
  }
  
  .feature-card i {
    font-size: 2.5rem;
    color: #0066cc;
    margin-bottom: 1rem;
  }
  
  .feature-card h3 {
    margin-bottom: 1rem;
  }
  
  .auth-section,
  .refund-section {
    max-width: 800px;
    margin: 0 auto;
    background-color: #fff;
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
  }
  
  .auth-section h2,
  .refund-section h2 {
    text-align: center;
    margin-bottom: 0.5rem;
  }
  
  .auth-section > p,
  .refund-section > p {
    text-align: center;
    margin-bottom: 2rem;
    color: #666;
  }
  
  .form-group {
    margin-bottom: 2rem;
    border: 1px solid #e0e0e0;
    border-radius: 0.5rem;
    padding: 1.5rem;
  }
  
  .form-group h3 {
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid #e0e0e0;
    color: #0066cc;
  }
  
  .form-row {
    display: flex;
    gap: 1rem;
    margin-bottom: 1rem;
  }
  
  .form-control {
    margin-bottom: 1rem;
    flex: 1;
  }
  
  .form-control label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
  }
  
  .form-control input,
  .form-control select,
  .form-control textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ddd;
    border-radius: 0.25rem;
    font-family: inherit;
    font-size: 1rem;
  }
  
  .form-control input:focus,
  .form-control select:focus,
  .form-control textarea:focus {
    outline: none;
    border-color: #0066cc;
    box-shadow: 0 0 0 2px rgba(0, 102, 204, 0.2);
  }
  
  .form-actions {
    display: flex;
    justify-content: center;
    gap: 1rem;
  }
  
  .form-actions .btn {
    min-width: 150px;
  }
  
  .form-actions .btn-primary {
    background-color: #0066cc;
    color: #fff;
  }
  
  .form-actions .btn-primary:hover {
    background-color: #004499;
  }
  
  .form-actions .btn-secondary {
    background-color: #f0f0f0;
    color: #333;
    border: 1px solid #ddd;
  }
  
  .form-actions .btn-secondary:hover {
    background-color: #e0e0e0;
  }
  
  .alert {
    padding: 1rem;
    border-radius: 0.25rem;
    margin-bottom: 1.5rem;
  }
  
  .alert-danger {
    background-color: #fff0f0;
    border: 1px solid #ffcccc;
    color: #cc0000;
  }
  
  .alert ul {
    margin-left: 1.5rem;
  }
  
  .confirmation-section {
    max-width: 800px;
    margin: 0 auto;
  }
  
  .success-message,
  .error-message {
    background-color: #fff;
    padding: 2rem;
    border-radius: 0.5rem;
    text-align: center;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
  }
  
  .success-message i,
  .error-message i {
    font-size: 4rem;
    margin-bottom: 1rem;
  }
  
  .success-message i {
    color: #00cc66;
  }
  
  .error-message i {
    color: #cc0000;
  }
  
  .next-steps {
    text-align: left;
    margin: 2rem 0;
    padding: 1.5rem;
    background-color: #f8f9fa;
    border-radius: 0.5rem;
  }
  
  .next-steps h3 {
    margin-bottom: 1rem;
  }
  
  .next-steps ol {
    margin-left: 1.5rem;
  }
  
  .next-steps li {
    margin-bottom: 0.5rem;
  }
  
  .error-section {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 60vh;
  }
  
  .error-content {
    text-align: center;
    max-width: 500px;
  }
  
  .error-content h2 {
    font-size: 6rem;
    color: #0066cc;
    margin-bottom: 0;
  }
  
  .error-content h3 {
    margin-bottom: 1rem;
  }
  
  .error-content p {
    margin-bottom: 2rem;
    color: #666;
  }
  
  footer {
    background-color: #333;
    color: #fff;
    padding: 2rem 0;
    text-align: center;
  }
  
  @media (max-width: 768px) {
    .menu-toggle {
      display: block;
    }
  
    nav {
      position: fixed;
      top: 0;
      right: -300px;
      width: 300px;
      height: 100vh;
      background-color: #fff;
      box-shadow: -5px 0 15px rgba(0, 0, 0, 0.1);
      transition: right 0.3s;
      z-index: 1001;
    }
  
    nav.active {
      right: 0;
    }
  
    nav ul {
      flex-direction: column;
      padding: 2rem;
    }
  
    nav ul li {
      margin: 1rem 0;
    }
  
    .form-row {
      flex-direction: column;
      gap: 0;
    }
  
    .hero h2 {
      font-size: 2rem;
    }
  
    .product-grid {
      grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    }
  }