:root {
  /* Color scheme */
  color-scheme: light dark;
  
  /* Light theme */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --surface: #ffffff;
  --surface-elevated: #f8fafc;
  --border: #e2e8f0;
  --border-light: #f1f5f9;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-disabled: #94a3b8;
  
  /* Brand colors */
  --primary: #3b82f6;
  --primary-hover: #2563eb;
  --primary-light: #dbeafe;
  --secondary: #6366f1;
  --secondary-hover: #5b5bd6;
  --secondary-light: #e0e7ff;
  --success: #22c55e;
  --success-light: #dcfce7;
  --warning: #f59e0b;
  --warning-light: #fef3c7;
  --error: #ef4444;
  --error-light: #fee2e2;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px -1px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
  
  /* Border radius */
  --radius: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 20px;
  
  /* Transitions */
  --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark theme */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-tertiary: #334155;
    --surface: #1e293b;
    --surface-elevated: #334155;
    --border: #475569;
    --border-light: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    --text-disabled: #64748b;
    --primary-light: #1e40af;
    --secondary-light: #4338ca;
    --success-light: #166534;
    --warning-light: #d97706;
    --error-light: #dc2626;
  }
}

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

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  transition: var(--transition);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px;
}

/* Header */
.main-header {
  text-align: center;
  margin-bottom: 40px;
  padding: 40px 20px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  border-radius: var(--radius-2xl);
  color: white;
  position: relative;
  overflow: hidden;
}

.main-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg width="60" height="60" viewBox="0 0 60 60" xmlns="http://www.w3.org/2000/svg"><g fill="none" fill-rule="evenodd"><g fill="%23ffffff" fill-opacity="0.1"><circle cx="30" cy="30" r="2"/></g></svg>');
  opacity: 0.5;
}

.header-icon {
  font-size: 3rem;
  margin-bottom: 16px;
  position: relative;
  z-index: 1;
}

.main-header h1 {
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 700;
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}

.main-header .subtitle {
  font-size: 1.1rem;
  opacity: 0.9;
  position: relative;
  z-index: 1;
}

/* Section titles */
.section-title {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 24px;
  color: var(--text-primary);
}

.section-icon {
  font-size: 1.5rem;
}

.image-count {
  font-size: 0.9rem;
  font-weight: 400;
  color: var(--text-muted);
  margin-left: auto;
}

/* Panels */
.upload-panel,
.settings-panel,
.results-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 32px;
  margin-bottom: 32px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.upload-panel:hover,
.settings-panel:hover,
.results-panel:hover {
  box-shadow: var(--shadow-md);
}

/* Upload area */
.upload-area {
  margin-bottom: 24px;
}

.drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius-xl);
  padding: 48px 24px;
  text-align: center;
  cursor: pointer;
  transition: var(--transition);
  background: var(--bg-secondary);
  position: relative;
}

.drop-zone:hover,
.drop-zone:focus {
  border-color: var(--primary);
  background: var(--primary-light);
  outline: none;
}

.drop-zone.hover {
  border-color: var(--primary);
  background: var(--primary-light);
  transform: scale(1.02);
}

.drop-icon {
  font-size: 3rem;
  margin-bottom: 16px;
}

.drop-title {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.drop-text {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.supported-formats {
  font-size: 0.875rem;
  color: var(--text-muted);
}

/* Settings groups */
.settings-group {
  margin-bottom: 32px;
}

.group-title {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 20px;
  color: var(--text-primary);
  padding-bottom: 8px;
  border-bottom: 2px solid var(--border-light);
}

.settings-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  align-items: end;
}

/* Form groups */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-weight: 500;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.form-group input[type="text"],
.form-group select {
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 1rem;
  transition: var(--transition);
}

.form-group input[type="text"]:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

/* Color input wrapper */
.color-input-wrapper {
  display: flex;
  align-items: center;
  gap: 8px;
  position: relative;
}

.color-input-wrapper input[type="color"] {
  width: 40px;
  height: 32px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: transparent;
  cursor: pointer;
  transition: var(--transition);
}

.color-input-wrapper input[type="color"]:hover {
  border-color: var(--primary);
}

.color-preview {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--color, #ffffff);
}

.color-toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.color-toggle .toggle-slider {
  width: 32px;
  height: 16px;
  border-radius: 8px;
}

.color-toggle .toggle-slider::before {
  width: 12px;
  height: 12px;
  left: 2px;
  top: 2px;
}

.color-toggle .toggle-input:checked + .toggle-slider::before {
  transform: translateX(16px);
}

/* Preview Panel */
.preview-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 32px;
  margin-bottom: 32px;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.preview-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.preview-canvas {
  max-width: 100%;
  max-height: 400px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  background: linear-gradient(45deg, #f0f0f0 25%, transparent 25%),
              linear-gradient(-45deg, #f0f0f0 25%, transparent 25%),
              linear-gradient(45deg, transparent 75%, #f0f0f0 75%),
              linear-gradient(-45deg, transparent 75%, #f0f0f0 75%);
  background-size: 16px 16px;
  background-position: 0 0, 0 8px, 8px -8px, -8px 0px;
}

.preview-controls {
  display: flex;
  align-items: center;
  gap: 16px;
}

.preview-info {
  font-weight: 500;
  color: var(--text-secondary);
  min-width: 60px;
  text-align: center;
}

/* Enhanced file input wrapper */
.file-input-wrapper {
  position: relative;
  overflow: hidden;
  display: inline-block;
  width: 100%;
}

.file-input-wrapper input[type="file"] {
  position: absolute;
  left: -9999px;
  opacity: 0;
}

.file-input-text {
  display: block;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-secondary);
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  position: relative;
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
}

.file-input-text:hover {
  border-color: var(--primary);
  background: var(--primary-light);
}

.file-input-text.has-file {
  color: var(--text-primary);
  background: var(--success-light);
  border-color: var(--success);
}

/* Enhanced slider containers */
.slider-container {
  display: flex;
  align-items: center;
  gap: 12px;
}

.slider-container input[type="range"] {
  flex: 1;
  height: 6px;
  border-radius: 3px;
  background: linear-gradient(to right, var(--primary) 0%, var(--primary) var(--fill, 40%), var(--border) var(--fill, 40%), var(--border) 100%);
  outline: none;
  -webkit-appearance: none;
  transition: var(--transition);
}

.slider-container input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.slider-container input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.1);
  box-shadow: var(--shadow-md);
}

.slider-container input[type="range"]::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  border: none;
  box-shadow: var(--shadow);
  transition: var(--transition);
}

.slider-value {
  font-weight: 500;
  color: var(--text-primary);
  min-width: 60px;
  text-align: center;
  padding: 4px 8px;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  font-size: 0.875rem;
  border: 1px solid var(--border-light);
}

/* Enhanced buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius-lg);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  min-width: 140px;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left 0.5s;
}

.btn:hover::before {
  left: 100%;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  box-shadow: var(--shadow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--surface-elevated);
  color: var(--text-primary);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: var(--bg-tertiary);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.btn-outline:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border-color: var(--text-muted);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

.btn-icon {
  font-size: 1.1rem;
}

/* Enhanced actions section */
.actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--border-light);
}

/* Progress indicator */
.progress-indicator {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: var(--border);
  z-index: 9999;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.progress-indicator.active {
  opacity: 1;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  width: 0%;
  transition: width 0.3s ease;
}

/* Enhanced notifications */
.notification {
  position: fixed;
  top: 20px;
  right: 20px;
  padding: 16px 24px;
  border-radius: var(--radius-lg);
  color: white;
  font-weight: 500;
  z-index: 1000;
  max-width: 350px;
  box-shadow: var(--shadow-xl);
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.notification.success {
  background: linear-gradient(135deg, var(--success), #16a34a);
}

.notification.error {
  background: linear-gradient(135deg, var(--error), #dc2626);
}

.notification.warning {
  background: linear-gradient(135deg, var(--warning), #d97706);
}

.notification.info {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
}

/* Slider containers */
.slider-container {
  display: flex;
  align-items: center;
  gap: 12px;
}

.slider-container input[type="range"] {
  flex: 1;
  height: 6px;
  border-radius: 3px;
  background: var(--border);
  outline: none;
  -webkit-appearance: none;
}

.slider-container input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  box-shadow: var(--shadow);
}

.slider-container input[type="range"]::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--primary);
  cursor: pointer;
  border: none;
  box-shadow: var(--shadow);
}

.slider-value {
  font-weight: 500;
  color: var(--text-primary);
  min-width: 60px;
  text-align: center;
  padding: 4px 8px;
  background: var(--bg-tertiary);
  border-radius: var(--radius);
  font-size: 0.875rem;
}

/* Toggle switch */
.toggle-label {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  font-weight: 500;
}

.toggle-input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: relative;
  width: 48px;
  height: 24px;
  background: var(--border);
  border-radius: 12px;
  transition: var(--transition);
}

.toggle-slider::before {
  content: '';
  position: absolute;
  height: 18px;
  width: 18px;
  left: 3px;
  top: 3px;
  background: white;
  border-radius: 50%;
  transition: var(--transition);
  box-shadow: var(--shadow);
}

.toggle-input:checked + .toggle-slider {
  background: var(--primary);
}

.toggle-input:checked + .toggle-slider::before {
  transform: translateX(24px);
}

.toggle-text {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Actions */
.actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 32px;
  padding-top: 24px;
  border-top: 1px solid var(--border-light);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius-lg);
  font-size: 1rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition);
  border: none;
  min-width: 140px;
  justify-content: center;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: white;
  box-shadow: var(--shadow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: var(--surface-elevated);
  color: var(--text-primary);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: var(--bg-tertiary);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.btn-outline {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}

.btn-outline:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border-color: var(--text-muted);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

.btn-icon {
  font-size: 1.1rem;
}

/* Results grid */
.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 20px;
  margin-top: 24px;
}

.result-card {
  background: var(--surface-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.result-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.result-card img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  display: block;
}

.card-info {
  padding: 16px;
}

.card-name {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-primary);
  margin-bottom: 8px;
  truncate: ellipsis;
  overflow: hidden;
  white-space: nowrap;
}

.card-actions {
  display: flex;
  gap: 8px;
}

.card-btn {
  flex: 1;
  padding: 8px 12px;
  font-size: 0.875rem;
  min-width: auto;
}

/* Responsive design */
@media (max-width: 768px) {
  .container {
    padding: 16px;
  }
  
  .main-header {
    padding: 24px 16px;
    margin-bottom: 24px;
  }
  
  .upload-panel,
  .settings-panel,
  .results-panel {
    padding: 20px;
    margin-bottom: 20px;
  }
  
  .settings-row {
    grid-template-columns: 1fr;
    gap: 16px;
  }
  
  .actions {
    flex-direction: column;
    align-items: stretch;
  }
  
  .btn {
    width: 100%;
  }
  
  .results-grid {
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
  }
  
  .drop-zone {
    padding: 32px 16px;
  }
}

@media (max-width: 480px) {
  .main-header h1 {
    font-size: 1.8rem;
  }
  
  .section-title {
    font-size: 1.3rem;
  }
  
  .results-grid {
    grid-template-columns: 1fr;
  }
  
.drop-zone {
  padding: 24px 12px;
}

.drop-icon {
  font-size: 2rem;
}
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

/* Loading states */
.loading {
  opacity: 0.7;
  pointer-events: none;
}

.loading .btn {
  position: relative;
}

.loading .btn::after {
  content: '';
  position: absolute;
  width: 16px;
  height: 16px;
  margin: auto;
  border: 2px solid transparent;
  border-top-color: currentColor;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Animation for new images */
.result-card.new {
  animation: slideInUp 0.5s ease-out;
}

@keyframes slideInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}