/* ===================================================
   Image Diff Tool - Modern CSS Design System
   =================================================== */

:root {
  /* Color Palette */
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: rgba(20, 20, 30, 0.8);
  --bg-glass: rgba(255, 255, 255, 0.03);

  --text-primary: #ffffff;
  --text-secondary: #a0a0b0;
  --text-muted: #6a6a7a;

  --accent-primary: #6366f1;
  --accent-secondary: #8b5cf6;
  --accent-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a855f7 100%);

  --success: #10b981;
  --success-glow: rgba(16, 185, 129, 0.3);

  --danger: #ef4444;
  --danger-glow: rgba(239, 68, 68, 0.3);

  --warning: #f59e0b;

  --border-color: rgba(255, 255, 255, 0.08);
  --border-hover: rgba(255, 255, 255, 0.15);

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 40px rgba(99, 102, 241, 0.15);

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 0.75rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;

  /* Border Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* ===================================================
   Base Styles
   =================================================== */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Background gradient animation */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background:
    radial-gradient(ellipse at 20% 20%, rgba(99, 102, 241, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 80%, rgba(139, 92, 246, 0.08) 0%, transparent 50%),
    radial-gradient(ellipse at 50% 50%, rgba(168, 85, 247, 0.05) 0%, transparent 70%);
  pointer-events: none;
  z-index: -1;
}

/* ===================================================
   Layout
   =================================================== */

.app {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

.main {
  flex: 1;
  max-width: 1400px;
  margin: 0 auto;
  padding: var(--spacing-xl);
  width: 100%;
}

/* ===================================================
   Glass Card Effect
   =================================================== */

.glass-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--shadow-md);
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal);
}

.glass-card:hover {
  border-color: var(--border-hover);
}

/* ===================================================
   Header
   =================================================== */

.header {
  padding: var(--spacing-xl) var(--spacing-2xl);
  text-align: center;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-glass);
  backdrop-filter: blur(10px);
}

.header-content {
  max-width: 1400px;
  margin: 0 auto;
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
}

.logo-icon {
  width: 48px;
  height: 48px;
  background: var(--accent-gradient);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-glow);
}

.logo-icon svg {
  width: 28px;
  height: 28px;
  color: white;
}

.logo h1 {
  font-size: 2rem;
  font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline {
  color: var(--text-secondary);
  font-size: 1rem;
}

/* ===================================================
   Input Section
   =================================================== */

.input-section {
  padding: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
}

.section-title {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 1.25rem;
  font-weight: 600;
  margin-bottom: var(--spacing-lg);
}

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

.compare-form {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xl);
}

.input-row {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-lg);
}

.input-group {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

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

.input-group input[type="url"] {
  width: 100%;
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.input-group input[type="url"]:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.input-group input[type="url"]::placeholder {
  color: var(--text-muted);
}

.input-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.vs-badge {
  padding: var(--spacing-md);
  background: var(--accent-gradient);
  border-radius: 50%;
  font-weight: 700;
  font-size: 0.875rem;
  align-self: center;
  margin-top: 1.5rem;
  box-shadow: var(--shadow-glow);
}

/* Options Row */
.options-row {
  display: flex;
  gap: var(--spacing-lg);
}

.option-group {
  flex: 1;
  max-width: 300px;
}

.slider-container {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

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

.slider-container input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  background: var(--accent-primary);
  border-radius: 50%;
  cursor: pointer;
  box-shadow: 0 0 10px rgba(99, 102, 241, 0.5);
  transition: transform var(--transition-fast);
}

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

.slider-value {
  min-width: 3rem;
  padding: var(--spacing-xs) var(--spacing-sm);
  background: var(--bg-secondary);
  border-radius: var(--radius-sm);
  text-align: center;
  font-size: 0.875rem;
  font-weight: 500;
}

/* Compare Button */
.compare-btn {
  align-self: center;
  padding: var(--spacing-md) var(--spacing-2xl);
  background: var(--accent-gradient);
  border: none;
  border-radius: var(--radius-md);
  color: white;
  font-size: 1rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: transform var(--transition-fast), box-shadow var(--transition-fast);
  box-shadow: var(--shadow-glow);
  position: relative;
  overflow: hidden;
}

.compare-btn:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 0 50px rgba(99, 102, 241, 0.3);
}

.compare-btn:active:not(:disabled) {
  transform: translateY(0);
}

.compare-btn:disabled {
  opacity: 0.7;
  cursor: not-allowed;
}

.compare-btn .btn-loading {
  display: none;
}

.compare-btn.loading .btn-text {
  display: none;
}

.compare-btn.loading .btn-loading {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
}

.spinner {
  width: 20px;
  height: 20px;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  from {
    transform: rotate(0deg);
  }

  to {
    transform: rotate(360deg);
  }
}

/* ===================================================
   Results Section
   =================================================== */

.results-section {
  animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hidden {
  display: none !important;
}

/* Stats Grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.stat-card {
  padding: var(--spacing-lg);
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.stat-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.stat-icon svg {
  width: 24px;
  height: 24px;
}

.stat-icon.similarity {
  background: rgba(16, 185, 129, 0.15);
  color: var(--success);
}

.stat-icon.difference {
  background: rgba(239, 68, 68, 0.15);
  color: var(--danger);
}

.stat-icon.pixels {
  background: rgba(245, 158, 11, 0.15);
  color: var(--warning);
}

.stat-icon.time {
  background: rgba(99, 102, 241, 0.15);
  color: var(--accent-primary);
}

.stat-content {
  display: flex;
  flex-direction: column;
}

.stat-value {
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.2;
}

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

/* Similarity Bar */
.similarity-bar-container {
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.similarity-bar-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: var(--spacing-sm);
  font-weight: 500;
}

.similarity-bar {
  height: 12px;
  background: var(--bg-secondary);
  border-radius: 6px;
  overflow: hidden;
}

.similarity-bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--danger) 0%, var(--warning) 50%, var(--success) 100%);
  border-radius: 6px;
  transition: width 1s ease;
  width: 0%;
}

/* ===================================================
   Image Viewer
   =================================================== */

.image-viewer {
  padding: var(--spacing-xl);
}

.viewer-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-lg);
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.view-tabs {
  display: flex;
  gap: var(--spacing-xs);
  background: var(--bg-secondary);
  padding: 4px;
  border-radius: var(--radius-md);
}

.view-tab {
  padding: var(--spacing-sm) var(--spacing-md);
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: 0.875rem;
  font-weight: 500;
  font-family: inherit;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.view-tab:hover {
  color: var(--text-primary);
}

.view-tab.active {
  background: var(--accent-primary);
  color: white;
}

/* Image Grid (Side by Side) */
.image-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--spacing-lg);
}

.image-panel {
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.panel-header {
  padding: var(--spacing-md);
  background: var(--bg-glass);
  font-size: 0.875rem;
  font-weight: 500;
  text-align: center;
  border-bottom: 1px solid var(--border-color);
}

.diff-panel .panel-header {
  background: linear-gradient(90deg, rgba(239, 68, 68, 0.1), rgba(239, 68, 68, 0.2));
}

.image-wrapper {
  padding: var(--spacing-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 300px;
}

.image-wrapper img {
  max-width: 100%;
  max-height: 400px;
  object-fit: contain;
  border-radius: var(--radius-sm);
}

/* Slider Compare */
.slider-compare {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.slider-image-container {
  position: relative;
  width: 100%;
  max-width: 800px;
  margin: 0 auto;
  overflow: hidden;
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  cursor: ew-resize;
}

.slider-img {
  display: block;
  width: 100%;
  height: auto;
}

.slider-img-before {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: contain;
  clip-path: inset(0 50% 0 0);
}

.slider-img-after {
  width: 100%;
  height: auto;
  object-fit: contain;
}

.slider-divider {
  position: absolute;
  top: 0;
  left: 50%;
  width: 4px;
  height: 100%;
  background: var(--accent-primary);
  transform: translateX(-50%);
  cursor: ew-resize;
  z-index: 10;
}

.slider-handle {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 40px;
  height: 40px;
  background: var(--accent-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
}

.slider-handle svg {
  width: 12px;
  height: 12px;
  color: white;
}

.slider-labels {
  display: flex;
  justify-content: space-between;
  padding: 0 var(--spacing-md);
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* Diff Only View */
.diff-only-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-lg);
}

.diff-only-container img {
  max-width: 100%;
  max-height: 600px;
  object-fit: contain;
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  padding: var(--spacing-md);
}

.diff-legend {
  display: flex;
  gap: var(--spacing-xl);
}

.legend-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.legend-color {
  width: 16px;
  height: 16px;
  border-radius: 4px;
}

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

.legend-color.gray {
  background: rgba(255, 255, 255, 0.3);
}

/* ===================================================
   Footer
   =================================================== */

.footer {
  padding: var(--spacing-xl);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  border-top: 1px solid var(--border-color);
}

/* ===================================================
   Responsive Design
   =================================================== */

@media (max-width: 1200px) {
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .image-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .main {
    padding: var(--spacing-md);
  }

  .input-row {
    flex-direction: column;
  }

  .vs-badge {
    align-self: center;
    margin: 0;
  }

  .stats-grid {
    grid-template-columns: 1fr;
  }

  .viewer-header {
    flex-direction: column;
    text-align: center;
  }

  .view-tabs {
    width: 100%;
    justify-content: center;
  }
}

/* ===================================================
   Mode Tabs
   =================================================== */

.mode-tabs {
  display: flex;
  gap: var(--spacing-xs);
  background: var(--bg-card);
  padding: 6px;
  border-radius: var(--radius-lg);
  margin-bottom: var(--spacing-xl);
  border: 1px solid var(--border-color);
  width: fit-content;
}

.mode-tab {
  padding: var(--spacing-sm) var(--spacing-lg);
  background: transparent;
  border: none;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  font-family: inherit;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.mode-tab:hover {
  color: var(--text-primary);
  background: var(--bg-glass);
}

.mode-tab.active {
  background: var(--accent-gradient);
  color: white;
  box-shadow: var(--shadow-glow);
}

.mode-content.hidden {
  display: none;
}

/* ===================================================
   Projects Section
   =================================================== */

.projects-section {
  padding: var(--spacing-xl);
}

.projects-list {
  display: grid;
  gap: var(--spacing-md);
}

.project-card {
  padding: var(--spacing-lg);
  cursor: default;
  transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.project-card:hover {
  border-color: var(--accent-primary);
  transform: translateY(-2px);
}

.project-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
}

.project-id {
  font-size: 1.25rem;
  font-weight: 700;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.status-badge {
  padding: 4px 10px;
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.status-badge.success {
  background: rgba(16, 185, 129, 0.15);
  color: var(--success);
}

.project-details {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: var(--spacing-md);
}

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

.compare-info {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: monospace;
}

.warning-text {
  font-size: 0.8rem;
  color: var(--warning);
}

.project-actions {
  display: flex;
  gap: var(--spacing-sm);
}

.compare-project-btn,
.view-result-btn {
  padding: var(--spacing-sm) var(--spacing-md);
  border: none;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  font-family: inherit;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.compare-project-btn {
  background: var(--accent-gradient);
  color: white;
}

.compare-project-btn:hover {
  box-shadow: var(--shadow-glow);
  transform: translateY(-1px);
}

.view-result-btn {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.view-result-btn:hover {
  border-color: var(--accent-primary);
}

.compare-project-btn:disabled {
  opacity: 0.7;
  cursor: not-allowed;
  transform: none;
}

/* Project Info in Results */
.project-info {
  padding: var(--spacing-md) var(--spacing-lg);
  margin-bottom: var(--spacing-lg);
}

.project-info-content {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.project-badge {
  padding: var(--spacing-xs) var(--spacing-md);
  background: var(--accent-gradient);
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.9rem;
}

.project-files {
  font-size: 0.9rem;
  color: var(--text-secondary);
  font-family: monospace;
}

/* Empty/Loading/Error States */
.loading-state,
.empty-state,
.error-state {
  padding: var(--spacing-2xl);
  text-align: center;
  color: var(--text-secondary);
}

.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-sm);
}

.empty-icon {
  font-size: 3rem;
  opacity: 0.5;
}

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

.empty-hint code {
  background: var(--bg-secondary);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.85em;
}

.error-state {
  color: var(--danger);
}

/* Small Spinner */
.spinner-small {
  display: inline-block;
  width: 14px;
  height: 14px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  vertical-align: middle;
  margin-right: 6px;
}

/* Type Badge */
.type-badge {
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.type-badge.image {
  background: linear-gradient(135deg, #6366f1, #8b5cf6);
  color: white;
}

.type-badge.pdf {
  background: linear-gradient(135deg, #ef4444, #f97316);
  color: white;
}

.type-badge.url {
  background: linear-gradient(135deg, #10b981, #14b8a6);
  color: white;
}

/* Source Path */
.source-path {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: monospace;
  background: var(--bg-secondary);
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  margin-left: auto;
}