/* DevMentors Design System - Image Format Comparison Tool */

/* ========================================
   CSS Variables (DevMentors Theme)
   ======================================== */
:root {
  /* Background Colors */
  --bg-primary: #000000;
  --bg-secondary: #0a0a0a;
  --bg-tertiary: #1a1a1a;

  /* Text Colors */
  --text-primary: #f9f9f9;
  --text-secondary: #999999;
  --text-tertiary: #666666;

  /* Accent Colors */
  --accent-primary: #48BDB8;
  --accent-light: #5ed4cf;
  --accent-dark: #2a2a2a;

  /* Border Colors */
  --border-color: #1a1a1a;
  --border-hover: #48BDB8;

  /* Spacing (4px base grid) */
  --space-xs: 8px;
  --space-sm: 12px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;

  /* Typography */
  --font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'Segoe UI', sans-serif;
  --font-size-xs: 12px;
  --font-size-sm: 14px;
  --font-size-md: 16px;
  --font-size-lg: 20px;
  --font-size-xl: 24px;
  --font-size-2xl: 32px;
  --font-size-3xl: 48px;
  --font-size-4xl: 56px;

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

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;

  /* Shadows */
  --shadow-hover: 0 8px 24px rgba(72, 189, 184, 0.3);
  --shadow-card: 0 4px 12px rgba(0, 0, 0, 0.3);
}

/* ========================================
   Reset & Base Styles
   ======================================== */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
}

/* ========================================
   Typography
   ======================================== */
h1 {
  font-size: var(--font-size-3xl);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
}

h2 {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  line-height: 1.1;
}

h3 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  line-height: 1.2;
}

.subtitle {
  font-size: var(--font-size-md);
  color: var(--text-secondary);
  font-weight: 400;
}

.meta {
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-tertiary);
}

/* ========================================
   Layout
   ======================================== */
.container {
  max-width: 1800px;
  margin: 0 auto;
  padding: var(--space-md);
}

.app-header {
  position: relative;
  text-align: center;
  padding: var(--space-lg) 0;
  border-bottom: 1px solid var(--border-color);
  margin-bottom: var(--space-lg);
}

.header-logo {
  margin-bottom: var(--space-md);
}

.devmentors-logo {
  height: 32px;
  opacity: 0.9;
  transition: opacity var(--transition-fast);
}

.devmentors-logo:hover {
  opacity: 1;
}

/* Language Switcher - Top Right */
.lang-switcher {
  position: absolute;
  top: var(--space-md);
  right: var(--space-md);
  display: flex;
  gap: 4px;
  background: var(--bg-tertiary);
  padding: 4px;
  border-radius: var(--radius-sm);
  z-index: 100;
}

.lang-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  border: none;
  border-radius: 4px;
  background: transparent;
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: var(--font-size-xs);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.lang-btn:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.05);
}

.lang-btn.active {
  background: var(--accent-primary);
  color: var(--bg-primary);
}

.flag-icon {
  font-size: 16px;
  line-height: 1;
}

/* Header Emoji */
.header-emoji {
  font-size: 0.85em;
}

.app-header h1 {
  margin-bottom: var(--space-xs);
}

/* Triple View Layout */
.main-content.triple-view {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: var(--space-lg);
  min-height: calc(100vh - 180px);
}

.viewers-section {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.viewers-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

/* ========================================
   Viewer Panels
   ======================================== */
.viewer-panel {
  display: flex;
  flex-direction: column;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color var(--transition-normal);
}

.viewer-panel:hover {
  border-color: var(--border-hover);
}

.panel-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: var(--bg-tertiary);
  border-bottom: 1px solid var(--border-color);
}

.format-label {
  font-weight: 700;
  font-size: var(--font-size-sm);
  color: var(--text-primary);
}

.format-label.jxl-label {
  color: var(--accent-primary);
}

/* Format Info Button */
.format-info-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 18px;
  height: 18px;
  padding: 0;
  border: none;
  background: transparent;
  color: var(--text-tertiary);
  cursor: pointer;
  transition: color var(--transition-fast);
}

.format-info-btn:hover {
  color: var(--accent-primary);
}

/* Modal */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

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

.modal-content {
  position: relative;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  max-width: 500px;
  width: 90%;
  max-height: 80vh;
  overflow-y: auto;
  transform: scale(0.9);
  transition: transform var(--transition-normal);
}

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

.modal-close {
  position: absolute;
  top: var(--space-md);
  right: var(--space-md);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  padding: 0;
  border: none;
  background: var(--bg-tertiary);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.modal-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: var(--space-md);
  padding-right: var(--space-xl);
}

.modal-body {
  color: var(--text-secondary);
  font-size: var(--font-size-sm);
  line-height: 1.7;
}

.modal-body p {
  margin-bottom: var(--space-sm);
}

.modal-body p:last-child {
  margin-bottom: 0;
}

.modal-body strong {
  color: var(--text-primary);
}

.modal-body ul {
  margin: 0 0 var(--space-sm) 0;
  padding-left: var(--space-lg);
}

.modal-body li {
  margin-bottom: var(--space-xs);
  line-height: 1.5;
}

.modal-body li:last-child {
  margin-bottom: 0;
}

.modal-body .highlight {
  color: var(--accent-primary);
  font-weight: 600;
}

.modal-body code {
  background: var(--bg-tertiary);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: var(--font-size-xs);
}

.format-meta {
  font-size: var(--font-size-xs);
  color: var(--text-tertiary);
}

.panel-size {
  margin-left: auto;
  font-size: var(--font-size-xs);
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--bg-secondary);
  padding: 2px 8px;
  border-radius: 4px;
}

/* ========================================
   Image Container (per panel)
   ======================================== */
.image-container {
  position: relative;
  overflow: hidden;
  height: 520px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-primary);
}

.image-wrapper {
  width: 100%;
  height: 100%;
  overflow: auto;
  cursor: grab;
  position: relative;
}

.image-wrapper:active {
  cursor: grabbing;
}

.image-wrapper img {
  max-width: none;
  display: block;
  user-select: none;
  -webkit-user-drag: none;
}

.image-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  color: var(--text-tertiary);
  padding: var(--space-lg);
  text-align: center;
}

.image-placeholder svg {
  width: 48px;
  height: 48px;
  opacity: 0.5;
}

.image-placeholder p {
  font-size: var(--font-size-sm);
}

.zoom-indicator {
  position: absolute;
  bottom: var(--space-xs);
  right: var(--space-xs);
  background: rgba(0, 0, 0, 0.8);
  padding: 4px 8px;
  border-radius: 4px;
  font-size: var(--font-size-xs);
  color: var(--text-secondary);
  z-index: 10;
}

/* ========================================
   JXL Warning Overlay
   ======================================== */
.jxl-warning-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 15;
}

.jxl-warning-content {
  text-align: center;
  color: #fbbf24;
  padding: var(--space-lg);
}

.jxl-warning-content svg {
  margin-bottom: var(--space-sm);
  opacity: 0.8;
}

.jxl-warning-content p {
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.jxl-hint {
  font-size: var(--font-size-xs);
  color: var(--text-tertiary);
}

.jxl-hint code {
  background: var(--bg-tertiary);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 11px;
}

.jxl-hint-link {
  color: var(--accent-primary);
  text-decoration: underline;
  font-weight: 600;
}

.jxl-hint-link:hover {
  color: var(--accent-light);
}

/* ========================================
   Controls Bar
   ======================================== */
.controls-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-lg);
  padding: var(--space-md);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  flex-wrap: wrap;
}

/* Sync Toggle */
.sync-toggle {
  display: flex;
  align-items: center;
}

.sync-label {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  cursor: pointer;
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.sync-label input[type="checkbox"] {
  display: none;
}

.sync-checkbox {
  width: 20px;
  height: 20px;
  border: 2px solid var(--border-color);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.sync-label input:checked + .sync-checkbox {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
}

.sync-label input:checked + .sync-checkbox::after {
  content: '✓';
  color: var(--bg-primary);
  font-size: 12px;
  font-weight: bold;
}

/* ========================================
   Zoom Controls
   ======================================== */
.zoom-controls {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.zoom-slider-container {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.zoom-slider {
  width: 120px;
  height: 4px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--bg-tertiary);
  border-radius: 2px;
  outline: none;
}

.zoom-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  background: var(--accent-primary);
  border-radius: 50%;
  cursor: pointer;
  transition: transform var(--transition-fast);
}

.zoom-slider::-webkit-slider-thumb:hover {
  transform: scale(1.2);
}

.zoom-slider::-moz-range-thumb {
  width: 16px;
  height: 16px;
  background: var(--accent-primary);
  border-radius: 50%;
  cursor: pointer;
  border: none;
}

.zoom-value {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  min-width: 50px;
  text-align: center;
}

.zoom-presets {
  display: flex;
  gap: var(--space-xs);
}

.zoom-preset-btn {
  padding: var(--space-xs) var(--space-sm);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: var(--font-size-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.zoom-preset-btn:hover {
  border-color: var(--accent-primary);
  color: var(--accent-primary);
}

.zoom-preset-btn.active {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: var(--bg-primary);
}

/* Reset Button */
.reset-btn {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-md);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-secondary);
  color: var(--text-secondary);
  font-family: var(--font-family);
  font-size: var(--font-size-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

.reset-btn svg {
  opacity: 0.7;
}

/* Sticky Controls Bar */
.sticky-controls {
  position: sticky;
  bottom: 0;
  z-index: 100;
  box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.5);
}

/* ========================================
   Cards
   ======================================== */
.card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: border-color var(--transition-normal);
}

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

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--border-color);
}

.card-title {
  font-size: var(--font-size-md);
  font-weight: 600;
}

/* ========================================
   Stats Panel
   ======================================== */
.stats-panel {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.stat-group {
  margin-bottom: var(--space-sm);
}

.stat-group-title {
  font-size: var(--font-size-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-tertiary);
  margin-bottom: var(--space-xs);
}

.stat-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-xs) 0;
  border-bottom: 1px solid var(--border-color);
}

.stat-row:last-child {
  border-bottom: none;
}

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

.stat-value {
  font-weight: 600;
  font-size: var(--font-size-sm);
}

.stat-value.highlight {
  color: var(--accent-primary);
}

.stat-value.positive {
  color: #4ade80;
}

.stat-value.negative {
  color: #f87171;
}

/* ========================================
   Size Comparison Bars
   ======================================== */
.size-comparison {
  margin-top: var(--space-sm);
}

.comparison-bar-container {
  margin-bottom: var(--space-md);
}

.comparison-bar-label {
  display: flex;
  justify-content: space-between;
  margin-bottom: var(--space-xs);
  font-size: var(--font-size-sm);
}

.comparison-bar-label .format-name {
  font-weight: 600;
}

.comparison-bar-label .size {
  color: var(--text-secondary);
}

/* Baseline-centered comparison bar */
.comparison-bar {
  height: 10px;
  background: var(--bg-tertiary);
  border-radius: 5px;
  overflow: visible;
  position: relative;
}

/* Center marker (JPEG baseline) */
.comparison-bar::after {
  content: '';
  position: absolute;
  left: 50%;
  top: -2px;
  bottom: -2px;
  width: 2px;
  background: var(--text-secondary);
  transform: translateX(-50%);
  z-index: 2;
}

.comparison-bar-fill {
  height: 100%;
  border-radius: 5px;
  transition: width var(--transition-normal), left var(--transition-normal);
  position: absolute;
  top: 0;
}

/* Smaller than JPEG (left side, green) */
.comparison-bar-fill.smaller {
  background: linear-gradient(90deg, #22c55e, #4ade80);
  right: 50%;
  left: auto;
}

/* Larger than JPEG (right side, red) */
.comparison-bar-fill.larger {
  background: linear-gradient(90deg, #f87171, #ef4444);
  left: 50%;
}

/* JPEG baseline marker */
.comparison-bar-fill.baseline {
  background: linear-gradient(90deg, #f59e0b, #fbbf24);
  left: 50%;
  width: 4px !important;
  transform: translateX(-50%);
  border-radius: 2px;
  z-index: 1;
}

.size-diff {
  font-size: var(--font-size-xs);
  margin-top: 4px;
  color: var(--text-tertiary);
}

.size-diff.smaller {
  color: #4ade80;
}

.size-diff.larger {
  color: #f87171;
}

/* ========================================
   Badges
   ======================================== */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: 4px var(--space-sm);
  background: rgba(72, 189, 184, 0.1);
  border: 1px solid var(--accent-primary);
  border-radius: var(--radius-xl);
  font-size: var(--font-size-xs);
  font-weight: 600;
  color: var(--accent-primary);
}

/* ========================================
   Image Picker (Custom Dropdown with Thumbnails)
   ======================================== */
.custom-select {
  position: relative;
  width: 100%;
}

.custom-select-trigger {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  width: 100%;
  padding: var(--space-xs) var(--space-sm);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-family);
  font-size: var(--font-size-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: left;
}

.custom-select-trigger:hover {
  border-color: var(--accent-primary);
}

.custom-select-trigger:focus {
  outline: none;
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 2px rgba(72, 189, 184, 0.2);
}

.custom-select.open .custom-select-trigger {
  border-color: var(--accent-primary);
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}

.select-thumbnail {
  width: 64px;
  height: 32px;
  object-fit: cover;
  border-radius: 4px;
  flex-shrink: 0;
}

.select-text {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.select-arrow {
  flex-shrink: 0;
  color: var(--text-tertiary);
  transition: transform var(--transition-fast);
}

.custom-select.open .select-arrow {
  transform: rotate(180deg);
}

.custom-select-dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background: var(--bg-tertiary);
  border: 1px solid var(--accent-primary);
  border-top: none;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  max-height: 300px;
  overflow-y: auto;
  z-index: 1000;
  display: none;
}

.custom-select.open .custom-select-dropdown {
  display: block;
}

.select-group {
  padding: var(--space-xs) 0;
}

.select-group:not(:last-child) {
  border-bottom: 1px solid var(--border-color);
}

.select-group-label {
  padding: var(--space-xs) var(--space-sm);
  font-size: var(--font-size-xs);
  font-weight: 600;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.select-option {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-xs) var(--space-sm);
  cursor: pointer;
  transition: background var(--transition-fast);
}

.select-option:hover {
  background: rgba(72, 189, 184, 0.1);
}

.select-option.selected {
  background: rgba(72, 189, 184, 0.15);
}

.option-thumbnail {
  width: 64px;
  height: 32px;
  object-fit: cover;
  border-radius: 4px;
  flex-shrink: 0;
}

.option-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  overflow: hidden;
}

.option-title {
  font-size: var(--font-size-sm);
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.option-dimensions {
  font-size: var(--font-size-xs);
  color: var(--text-tertiary);
}

/* ========================================
   Instructions Card (Collapsible)
   ======================================== */
.instructions-card {
  padding: 0;
}

.instructions-card .collapsible-header {
  cursor: pointer;
  list-style: none;
  margin-bottom: 0;
  padding: var(--space-md) var(--space-lg);
  border-bottom: none;
}

.instructions-card .collapsible-header::-webkit-details-marker {
  display: none;
}

.instructions-card .chevron-icon {
  transition: transform var(--transition-fast);
  color: var(--text-tertiary);
}

.instructions-card[open] .chevron-icon {
  transform: rotate(180deg);
}

.instructions-card[open] .collapsible-header {
  border-bottom: 1px solid var(--border-color);
}

.instructions-card .instructions-content {
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
  padding: var(--space-md) var(--space-lg);
}

.instructions-card p {
  margin-bottom: var(--space-xs);
}

.instructions-card code {
  display: block;
  background: var(--bg-tertiary);
  padding: var(--space-sm);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-xs);
  margin-bottom: var(--space-md);
  color: var(--accent-primary);
  word-break: break-all;
}

.instructions-card code:last-child {
  margin-bottom: 0;
}

.instruction-step {
  margin-top: var(--space-md);
  margin-bottom: var(--space-xs);
  color: var(--text-primary);
}

.instruction-step:first-child {
  margin-top: 0;
}

.instruction-note {
  font-size: var(--font-size-xs);
  color: var(--text-tertiary);
  margin-bottom: var(--space-sm);
}

.instruction-note a {
  color: var(--accent-primary);
  text-decoration: underline;
}

.instruction-note a:hover {
  color: var(--accent-light);
}

/* Download Buttons */
.download-section-title {
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-sm) !important;
}

.download-buttons {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  margin-bottom: var(--space-lg);
}

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-sm) var(--space-md);
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--accent-primary);
  font-family: var(--font-family);
  font-size: var(--font-size-xs);
  font-weight: 500;
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.download-btn:hover {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: var(--bg-primary);
}

.download-btn svg {
  flex-shrink: 0;
}


/* ========================================
   Keyboard Shortcuts (Collapsible)
   ======================================== */
.shortcuts-card {
  padding: 0;
}

.shortcuts-card .collapsible-header {
  cursor: pointer;
  list-style: none;
  margin-bottom: 0;
  padding: var(--space-md) var(--space-lg);
  border-bottom: none;
}

.shortcuts-card .collapsible-header::-webkit-details-marker {
  display: none;
}

.shortcuts-card .chevron-icon {
  transition: transform var(--transition-fast);
  color: var(--text-tertiary);
}

.shortcuts-card[open] .chevron-icon {
  transform: rotate(180deg);
}

.shortcuts-card[open] .collapsible-header {
  border-bottom: 1px solid var(--border-color);
}

.shortcuts-content {
  padding: var(--space-md) var(--space-lg);
}

.shortcut-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 4px 0;
  font-size: var(--font-size-sm);
  color: var(--text-secondary);
}

.shortcut-key {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 22px;
  height: 22px;
  padding: 0 6px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-primary);
}

/* ========================================
   Footer
   ======================================== */
.app-footer {
  text-align: center;
  padding: var(--space-xl) 0;
  margin-top: var(--space-xl);
  border-top: 1px solid var(--border-color);
}

.footer-credit {
  font-family: var(--font-family);
  font-size: var(--font-size-sm);
  color: var(--text-tertiary);
}

.footer-credit a {
  color: var(--accent-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

.footer-credit a:hover {
  color: var(--accent-light);
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1400px) {
  .main-content.triple-view {
    grid-template-columns: 1fr;
  }

  .stats-panel {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-md);
  }
}

@media (max-width: 1024px) {
  .viewers-grid {
    grid-template-columns: 1fr;
  }

  .viewer-panel {
    min-height: 300px;
  }

  h1 {
    font-size: var(--font-size-2xl);
  }
}

@media (max-width: 768px) {
  .container {
    padding: var(--space-sm);
  }

  h1 {
    font-size: var(--font-size-xl);
  }

  .controls-bar {
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-sm);
  }

  .zoom-controls {
    flex-wrap: wrap;
    justify-content: center;
  }

  .sync-toggle {
    justify-content: center;
  }

  .reset-btn {
    justify-content: center;
  }

  .image-container {
    min-height: 250px;
  }

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

/* ========================================
   Accessibility
   ======================================== */
:focus-visible {
  outline: 2px solid var(--accent-primary);
  outline-offset: 2px;
}

button:focus:not(:focus-visible) {
  outline: none;
}

/* Reduced motion preference */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}