/* ===== CSS VARIABLES & RESET ===== */
:root {
  /* Dark Theme Colors (Default) */
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-tertiary: #94a3b8;
  --border-light: #334155;
  --border-medium: #475569;
  
  /* Accent Colors */
  --accent-primary: #3b82f6;
  --accent-hover: #2563eb;
  --accent-light: #1e40af;
  --success: #10b981;
  --warning: #f59e0b;
  --error: #ef4444;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1), 0 8px 10px -6px rgb(0 0 0 / 0.1);
  
  /* Spacing & Sizing */
  --header-height: 80px;
  --sidebar-width: 350px;
  --border-radius: 12px;
  --border-radius-sm: 8px;
  --transition: all 0.2s ease;
}


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

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

/* ===== LAYOUT ===== */
.app-container {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.header {
  height: var(--header-height);
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border-light);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-content {
  max-width: 1400px;
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
}

.app-title {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--text-primary);
}

.title-icon {
  font-size: 1.75rem;
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 1rem;
}


.round-counter {
  background: var(--accent-primary);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius);
  font-weight: 500;
  font-size: 0.9rem;
}

.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 2rem;
  padding: 2rem;
  max-width: 1600px;
  margin: 0 auto;
  width: 100%;
}

/* ===== LOADING SCREEN ===== */
.loading-screen {
  grid-column: 1 / -1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 400px;
  gap: 1.5rem;
}

.loading-spinner {
  width: 50px;
  height: 50px;
  border: 4px solid var(--border-light);
  border-top: 4px solid var(--accent-primary);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

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

/* ===== COMPARISON INTERFACE ===== */
.comparison-container {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.comparison-header {
  text-align: center;
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--bg-tertiary);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 1rem;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-primary), var(--success));
  border-radius: 4px;
  transition: width 0.3s ease;
  width: 0%;
}

.comparison-prompt {
  font-size: 1.25rem;
  font-weight: 500;
  color: var(--text-secondary);
}

/* ===== IMAGE COMPARISON ===== */
.image-comparison {
  display: grid;
  grid-template-columns: minmax(300px, 1fr) auto minmax(300px, 1fr);
  gap: 1rem;
  align-items: start;
  width: 100%;
  max-width: min(95vw, 1400px);
  margin: 0 auto;
}

.image-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  background: var(--bg-secondary);
  border-radius: var(--border-radius);
  padding: 1.5rem;
  box-shadow: var(--shadow-md);
  transition: var(--transition);
}

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

.image-wrapper {
  position: relative;
  width: 100%;
  border-radius: var(--border-radius-sm);
  overflow: hidden;
  background: var(--bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.comparison-image {
  width: 100%;
  height: auto;
  max-width: 100%;
  max-height: 70vh;
  object-fit: contain;
  cursor: pointer;
  transition: var(--transition);
  opacity: 0;
  display: block;
}

.comparison-image.loaded {
  opacity: 1;
}

.comparison-image:hover {
  transform: scale(1.02);
}

.image-loading {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
}

.skeleton-loader {
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, var(--bg-tertiary) 25%, var(--border-light) 50%, var(--bg-tertiary) 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}

@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

/* ===== CAMERA INFO ===== */
.camera-info {
  text-align: center;
}

.camera-name {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.camera-details {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
}

.detail-item {
  background: var(--bg-tertiary);
  padding: 0.25rem 0.75rem;
  border-radius: 20px;
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-weight: 500;
}

/* ===== BUTTONS ===== */
.selection-button {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.875rem 1.5rem;
  background: var(--accent-primary);
  color: white;
  border: none;
  border-radius: var(--border-radius-sm);
  font-size: 1rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

.selection-button:hover {
  background: var(--accent-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.selection-button:active {
  transform: translateY(0);
}

.button-key {
  background: rgba(255, 255, 255, 0.2);
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-size: 0.875rem;
  font-weight: 600;
}

.vs-divider {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 60px;
}

.vs-text {
  background: var(--bg-secondary);
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
  border-radius: var(--border-radius);
  font-weight: 600;
  font-size: 1.125rem;
  box-shadow: var(--shadow-sm);
}

/* ===== SKIP SECTION ===== */
.skip-container {
  display: flex;
  justify-content: center;
  margin-top: 1rem;
}

.skip-button {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.25rem;
  background: var(--bg-secondary);
  color: var(--text-secondary);
  border: 2px solid var(--border-medium);
  border-radius: var(--border-radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

.skip-button:hover {
  background: var(--bg-tertiary);
  border-color: var(--accent-primary);
  color: var(--text-primary);
}

/* ===== STATISTICS PANEL ===== */
.statistics-panel {
  background: var(--bg-secondary);
  border-radius: var(--border-radius);
  padding: 1.5rem;
  box-shadow: var(--shadow-md);
  width: 100%;
  margin-top: 2rem;
}

.stats-title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1.5rem;
  text-align: center;
  color: var(--text-primary);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}

.stat-card {
  background: var(--bg-tertiary);
  padding: 1rem;
  border-radius: var(--border-radius-sm);
  text-align: center;
}

.stat-number {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--accent-primary);
  margin-bottom: 0.25rem;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.section-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

/* ===== BRAND PREFERENCES ===== */
.brand-preferences {
  margin-bottom: 2rem;
}

.brand-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.brand-item {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 0.5rem;
  align-items: center;
}

.brand-name {
  font-weight: 500;
  color: var(--text-primary);
}

.brand-percentage {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--accent-primary);
}

.brand-bar {
  grid-column: 1 / -1;
  height: 6px;
  background: var(--bg-tertiary);
  border-radius: 3px;
  overflow: hidden;
}

.brand-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-primary), var(--success));
  border-radius: 3px;
  transition: width 0.3s ease;
}

/* ===== TOP CAMERAS ===== */
.top-cameras {
  margin-bottom: 2rem;
}

.camera-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.camera-item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 0.75rem;
  align-items: center;
  padding: 0.5rem;
  background: var(--bg-tertiary);
  border-radius: var(--border-radius-sm);
}

.camera-rank {
  font-weight: 600;
  color: var(--accent-primary);
  font-size: 0.875rem;
}

.camera-model {
  font-weight: 500;
  color: var(--text-primary);
  font-size: 0.875rem;
}

.camera-wins {
  background: var(--accent-light);
  color: var(--accent-primary);
  padding: 0.125rem 0.5rem;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
}

/* ===== SESSION STATS ===== */
.session-stats {
  margin-bottom: 2rem;
}

.session-details {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.session-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.session-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.session-value {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-primary);
}

/* ===== CONTROL BUTTONS ===== */
.controls-section {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.control-button {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem;
  border: none;
  border-radius: var(--border-radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

.export-button {
  background: var(--success);
  color: white;
}

.export-button:hover {
  background: #059669;
  transform: translateY(-1px);
}

.reset-button {
  background: var(--error);
  color: white;
}

.reset-button:hover {
  background: #dc2626;
  transform: translateY(-1px);
}

/* ===== MODAL ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background: var(--bg-primary);
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-xl);
  max-width: 500px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  transform: scale(0.9);
  transition: var(--transition);
}

.modal-overlay.active .modal-content {
  transform: scale(1);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.5rem;
  border-bottom: 1px solid var(--border-light);
}

.modal-header h2 {
  font-size: 1.25rem;
  font-weight: 600;
}

.modal-close {
  width: 32px;
  height: 32px;
  border: none;
  background: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
}

.modal-close:hover {
  background: var(--bg-tertiary);
  color: var(--text-primary);
}

.modal-body {
  padding: 1.5rem;
}

.instructions {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.instruction-item {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.instruction-key {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  padding: 0.5rem;
  border-radius: var(--border-radius-sm);
  font-weight: 600;
  min-width: 60px;
  text-align: center;
  font-size: 0.875rem;
}

.instruction-text {
  color: var(--text-secondary);
}

.instructions-note {
  background: var(--bg-secondary);
  padding: 1rem;
  border-radius: var(--border-radius-sm);
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

.modal-footer {
  padding: 1.5rem;
  border-top: 1px solid var(--border-light);
  display: flex;
  justify-content: flex-end;
}

.btn-primary {
  background: var(--accent-primary);
  color: white;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: var(--border-radius-sm);
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

.btn-primary:hover {
  background: var(--accent-hover);
}

/* ===== TOAST ===== */
.toast {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  background: var(--bg-primary);
  color: var(--text-primary);
  padding: 1rem 1.5rem;
  border-radius: var(--border-radius);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--border-light);
  transform: translateX(100%);
  transition: var(--transition);
  z-index: 1000;
}

.toast.show {
  transform: translateX(0);
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 1200px) {
  :root {
    --sidebar-width: 300px;
  }
}

@media (max-width: 1024px) {
  .main-content {
    gap: 1.5rem;
  }
  
  .image-comparison {
    max-width: 98vw;
  }
  
}

@media (max-width: 768px) {
  .header-content {
    padding: 0 1rem;
  }
  
  .app-title {
    font-size: 1.25rem;
  }
  
  .main-content {
    padding: 1rem;
  }
  
  .image-comparison {
    grid-template-columns: 1fr;
    gap: 1rem;
    max-width: 100%;
  }
  
  
  .vs-divider {
    order: 2;
    height: auto;
    padding: 0.5rem 0;
  }
  
  .image-container.right {
    order: 3;
  }
  
  .statistics-panel {
    padding: 1.5rem;
  }
  
  .stats-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .header-controls {
    gap: 0.5rem;
  }
  
  .round-counter {
    padding: 0.375rem 0.75rem;
    font-size: 0.8rem;
  }
  
  .image-container {
    padding: 1rem;
  }
  
  .image-comparison {
    grid-template-columns: minmax(250px, 1fr);
    gap: 0.5rem;
  }
  
  
  .camera-details {
    flex-direction: column;
    align-items: center;
  }
  
  .selection-button {
    padding: 0.75rem 1rem;
    font-size: 0.9rem;
  }
  
  .statistics-panel {
    padding: 1rem;
  }
  
  .modal-content {
    width: 95%;
  }
}

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

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.comparison-container {
  animation: slideInUp 0.3s ease;
}

.image-container {
  animation: fadeIn 0.5s ease;
}

/* ===== ACCESSIBILITY ===== */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

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

/* Focus styles for keyboard navigation */
button:focus-visible,
.comparison-image:focus-visible {
  outline: 2px solid var(--accent-primary);
  outline-offset: 2px;
}

/* ===== PRINT STYLES ===== */
@media print {
  .header,
  .statistics-panel,
  .modal-overlay,
  .toast {
    display: none;
  }
  
  .main-content {
    display: block;
    padding: 0;
  }
  
  .image-comparison {
    display: flex;
    justify-content: space-between;
  }
  
  .image-container {
    width: 45%;
    box-shadow: none;
    border: 1px solid #ccc;
  }
}