:root {
    --primary: #4f46e5;
    --primary-light: #818cf8;
    --primary-dark: #3730a3;
    --secondary: #f97316;
    --background: #f8fafc;
    --text: #1e293b;
    --gray-50: #f8fafc;
    --gray-100: #f1f5f9;
    --gray-200: #e2e8f0;
    --gray-300: #cbd5e1;
    --gray-400: #94a3b8;
    --gray-800: #1e293b;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius-sm: 4px;
    --radius: 8px;
    --radius-lg: 12px;
  }
  
  * {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
  }
  
  body {
    background: linear-gradient(135deg, var(--gray-50), var(--gray-100));
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
  }
  
  .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
  }
  
  header {
    padding: 2.5rem 2rem;
    text-align: center;
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    color: white;
    border-radius: var(--radius-lg);
    margin-bottom: 3rem;
    box-shadow: var(--shadow-lg);
    position: relative;
    overflow: hidden;
  }
  
  header::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(45deg, rgba(255,255,255,0.1) 25%, transparent 25%),
                linear-gradient(-45deg, rgba(255,255,255,0.1) 25%, transparent 25%),
                linear-gradient(45deg, transparent 75%, rgba(255,255,255,0.1) 75%),
                linear-gradient(-45deg, transparent 75%, rgba(255,255,255,0.1) 75%);
    background-size: 20px 20px;
    opacity: 0.1;
  }
  
  h1 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -0.025em;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.1);
  }
  
  .subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 0.5rem;
    font-weight: 500;
  }
  
  .attribution {
    margin-top: 1rem;
    font-size: 0.875rem;
    opacity: 0.8;
    font-weight: 500;
  }
  
  nav {
    display: flex;
    justify-content: center;
    gap: 2rem;
    padding: 1rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
    margin-bottom: 2rem;
  }
  
  nav a {
    color: white;
    text-decoration: none;
    font-weight: 600;
    opacity: 0.9;
    transition: all 0.2s ease;
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    position: relative;
  }
  
  nav a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background-color: white;
    transition: width 0.2s ease;
  }
  
  nav a:hover::after {
    width: 100%;
  }
  
  nav a:hover {
    opacity: 1;
    background-color: rgba(255, 255, 255, 0.1);
  }
  
  nav a.active {
    background-color: rgba(255, 255, 255, 0.2);
    opacity: 1;
  }
  
  .main-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
  }
  
  @media (min-width: 768px) {
    .main-content {
      grid-template-columns: repeat(2, 1fr);
    }
  }
  
  .card {
    background: white;
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    border: 1px solid var(--gray-200);
  }
  
  .card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
  }
  
  .card-title {
    font-size: 1.5rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
  }
  
  .card-title svg {
    width: 1.5rem;
    height: 1.5rem;
    stroke-width: 2;
  }
  
  .upload-area {
    border: 2px dashed var(--gray-300);
    border-radius: var(--radius);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-bottom: 1.5rem;
    background-color: var(--gray-50);
  }
  
  .upload-area:hover, .upload-area.dragover {
    border-color: var(--primary);
    background-color: rgba(79, 70, 229, 0.05);
  }
  
  .upload-icon {
    font-size: 3rem;
    color: var(--gray-400);
    margin-bottom: 1rem;
  }
  
  #imagePreview {
    max-width: 100%;
    max-height: 300px;
    margin: 1.5rem auto;
    display: none;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
  }
  
  button {
    background-color: var(--primary);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius);
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
  }
  
  button:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
  }
  
  button:active {
    transform: translateY(0);
  }
  
  button:disabled {
    background-color: var(--gray-300);
    cursor: not-allowed;
    transform: none;
  }
  
  .button-secondary {
    background-color: var(--secondary);
  }
  
  .button-secondary:hover {
    background-color: #ea580c;
  }
  
  .results-section {
    margin-top: 2rem;
  }
  
  .result-card {
    background-color: var(--gray-50);
    border-radius: var(--radius);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    border: 1px solid var(--gray-200);
  }
  
  .result-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--primary-dark);
  }
  
  .result-content {
    background-color: white;
    padding: 1.25rem;
    border-radius: var(--radius);
    border: 1px solid var(--gray-200);
    overflow-wrap: break-word;
  }
  
  .result-image {
    max-width: 100%;
    border-radius: var(--radius);
    margin-top: 1rem;
    box-shadow: var(--shadow);
  }
  
  .loading-spinner {
    display: none;
    text-align: center;
    margin: 2rem 0;
  }
  
  .spinner {
    width: 2.5rem;
    height: 2.5rem;
    border: 3px solid rgba(79, 70, 229, 0.1);
    border-left-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto;
  }
  
  @keyframes spin {
    to {
      transform: rotate(360deg);
    }
  }
  
  .error-message {
    color: #dc2626;
    background-color: #fee2e2;
    padding: 1rem;
    border-radius: var(--radius);
    display: none;
    margin: 1rem 0;
    font-weight: 500;
    border: 1px solid #fecaca;
  }
  
  .info-text {
    color: var(--gray-400);
    font-size: 0.875rem;
    margin-top: 0.75rem;
  }
  
  .credits {
    text-align: center;
    margin-top: 3rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--gray-200);
    color: var(--gray-400);
    font-size: 0.875rem;
  }
  
  #login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, var(--gray-50), var(--gray-100));
    padding: 2rem;
  }
  
  .auth-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: 2.5rem;
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 400px;
    text-align: center;
    border: 1px solid var(--gray-200);
  }
  
  .auth-card h2 {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 1.5rem;
    font-weight: 700;
  }
  
  .auth-card input[type="text"],
  .auth-card input[type="password"],
  .auth-card input[type="email"] {
    width: 100%;
    padding: 0.75rem 1rem;
    margin-bottom: 1rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 1rem;
    transition: all 0.2s ease;
  }
  
  .auth-card input:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
  }
  
  .auth-card button {
    width: 100%;
    padding: 0.875rem;
    font-size: 1rem;
    font-weight: 600;
    margin-top: 0.5rem;
  }
  
  .auth-card .form-switch {
    margin-top: 1.25rem;
    font-size: 0.875rem;
    color: var(--gray-400);
  }
  
  .auth-card .form-switch a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.2s ease;
  }
  
  .auth-card .form-switch a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
  }
  
  .logout-button {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    background-color: var(--secondary);
    padding: 0.625rem 1.25rem;
    font-size: 0.875rem;
  }
  
  .features-list {
    list-style-type: none;
    padding: 0;
  }
  
  .features-list li {
    margin-bottom: 1rem;
    padding-left: 1.5rem;
    position: relative;
  }
  
  .features-list li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: bold;
  }
  
  .contact-info p, 
  .feedback-form p {
    margin-bottom: 1rem;
  }
  
  .feedback-form textarea {
    width: 100%;
    padding: 1rem;
    margin-bottom: 1rem;
    border: 1px solid var(--gray-300);
    border-radius: var(--radius);
    font-size: 1rem;
    min-height: 120px;
    resize: vertical;
    transition: all 0.2s ease;
  }
  
  .feedback-form textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
  }
  
  .video-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
    z-index: -1;
  }
  
  .video-bg video {
    position: absolute;
    top: 50%;
    left: 50%;
    min-width: 100%;
    min-height: 100%;
    width: auto;
    height: auto;
    transform: translate(-50%, -50%);
    object-fit: cover;
    filter: brightness(40%) saturate(120%);
  }
  
  @media (max-width: 640px) {
    .container {
      padding: 1rem;
    }
  
    header {
      padding: 1.5rem 1rem;
    }
  
    h1 {
      font-size: 2rem;
    }
  
    .card {
      padding: 1.5rem;
    }
  
    nav {
      gap: 1rem;
      flex-wrap: wrap;
    }
  
    nav a {
      padding: 0.375rem 0.75rem;
      font-size: 0.875rem;
    }
  }