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

:root {
  --navy: #1a237e;
  --navy-light: #283593;
  --accent: #00bcd4;
  --accent-dark: #0097a7;
  --bg: #f5f5f5;
  --surface: #ffffff;
  --text: #212121;
  --text-secondary: #757575;
  --border: #e0e0e0;
  --danger: #e53935;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.15);
  --radius: 12px;
  --radius-sm: 8px;
  --radius-full: 50%;
  --nav-height: 64px;
  --header-height: 56px;
  --sheet-width: 320px;
}

html, body {
  height: 100%;
  overflow: hidden;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}

#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  position: relative;
}

.hidden { display: none !important; }

/* Header */
#header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  padding: 0 16px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  z-index: 10;
  flex-shrink: 0;
}

.header-left, .header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
}

.logo-icon {
  width: 28px;
  height: 28px;
  color: var(--navy);
}

.logo-text {
  font-size: 18px;
  font-weight: 700;
  color: var(--navy);
}

.lang-select {
  padding: 4px 8px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  font-size: 13px;
  cursor: pointer;
}

.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: none;
  border-radius: var(--radius-full);
  background: transparent;
  cursor: pointer;
  color: var(--text-secondary);
  transition: background 0.2s;
}

.icon-btn:hover {
  background: var(--bg);
}

.icon-btn i {
  width: 20px;
  height: 20px;
}

/* Main Content */
#main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  position: relative;
}

/* Preview Area */
#previewArea {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
}

#emptyState {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 32px;
  text-align: center;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.empty-icon {
  width: 64px;
  height: 64px;
  color: var(--border);
}

#emptyState h2 {
  font-size: 20px;
  font-weight: 600;
  color: var(--text);
}

#emptyState p {
  font-size: 14px;
  color: var(--text-secondary);
  max-width: 280px;
}

.empty-actions {
  display: flex;
  gap: 12px;
  margin-top: 8px;
}

.btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border: none;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
}

.btn i { width: 18px; height: 18px; }

.btn-primary {
  background: var(--navy);
  color: white;
}

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

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

.btn-secondary:hover {
  background: var(--bg);
}

.btn-danger {
  background: transparent;
  color: var(--danger);
  border: 1px solid var(--danger);
  justify-content: center;
  width: 100%;
}

.btn-danger:hover {
  background: #ffebee;
}

/* Canvas Wrapper */
.canvas-wrapper {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  padding: 20px;
  overflow: auto;
  background: #ddd;
}

#mainCanvas {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
  border-radius: 4px;
  box-shadow: var(--shadow-lg);
  background: white;
}

/* Camera View */
#cameraView {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: black;
  z-index: 100;
  display: flex;
  flex-direction: column;
}

#cameraView.hidden { display: none; }

#video {
  flex: 1;
  width: 100%;
  object-fit: cover;
}

.camera-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
}

.frame-guide {
  width: 80%;
  max-width: 400px;
  aspect-ratio: 3/4;
  border: 2px solid rgba(255, 255, 255, 0.5);
  border-radius: 4px;
}

.camera-controls {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 40px;
  align-items: center;
}

.capture-btn {
  width: 72px;
  height: 72px;
  border: 4px solid white;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.3);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s;
}

.capture-btn:active {
  transform: scale(0.9);
}

.capture-btn i {
  width: 48px;
  height: 48px;
  color: white;
}

/* Bottom Navigation */
#bottomNav {
  display: flex;
  align-items: center;
  justify-content: space-around;
  height: var(--nav-height);
  background: var(--surface);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
  padding: 0 8px;
}

.nav-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  padding: 6px 12px;
  border: none;
  background: transparent;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 11px;
  transition: color 0.2s;
  border-radius: var(--radius-sm);
}

.nav-btn:hover {
  color: var(--navy);
  background: var(--bg);
}

.nav-btn i {
  width: 22px;
  height: 22px;
}

/* Sheet Panels */
.sheet-panel {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  width: var(--sheet-width);
  max-width: 90vw;
  background: var(--surface);
  box-shadow: var(--shadow-lg);
  z-index: 50;
  display: flex;
  flex-direction: column;
  animation: slideIn 0.3s ease;
  overflow: hidden;
}

@keyframes slideIn {
  from { transform: translateX(100%); }
  to { transform: translateX(0); }
}

.sheet-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.sheet-header h3 {
  font-size: 16px;
  font-weight: 600;
}

.sheet-body {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.filter-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.filter-group label {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
}

.filter-slider {
  width: 100%;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--bg);
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}

.filter-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--navy);
  border-radius: var(--radius-full);
  cursor: pointer;
  box-shadow: var(--shadow);
}

.filter-slider::-moz-range-thumb {
  width: 20px;
  height: 20px;
  background: var(--navy);
  border-radius: var(--radius-full);
  cursor: pointer;
  border: none;
}

.filter-val {
  font-size: 12px;
  color: var(--text-secondary);
  text-align: right;
  margin-top: -4px;
}

.filter-divider {
  height: 1px;
  background: var(--border);
  margin: 4px 0;
}

.toggle-group {
  flex-direction: row;
  align-items: center;
  justify-content: space-between;
}

.toggle {
  position: relative;
  display: inline-block;
  width: 44px;
  height: 24px;
  cursor: pointer;
}

.toggle input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  inset: 0;
  background: var(--border);
  border-radius: 24px;
  transition: 0.3s;
}

.toggle-slider::before {
  content: '';
  position: absolute;
  left: 2px;
  bottom: 2px;
  width: 20px;
  height: 20px;
  background: white;
  border-radius: var(--radius-full);
  transition: 0.3s;
}

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

.toggle input:checked + .toggle-slider::before {
  transform: translateX(20px);
}

.filter-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.filter-action-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  cursor: pointer;
  font-size: 11px;
  color: var(--text-secondary);
  transition: all 0.2s;
}

.filter-action-btn:hover {
  border-color: var(--navy);
  color: var(--navy);
  background: #e8eaf6;
}

.filter-action-btn i {
  width: 20px;
  height: 20px;
}

/* Export Buttons */
.export-btn {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  cursor: pointer;
  transition: all 0.2s;
  text-align: left;
}

.export-btn:hover {
  border-color: var(--navy);
  background: #e8eaf6;
}

.export-btn i {
  width: 28px;
  height: 28px;
  color: var(--navy);
  flex-shrink: 0;
}

.export-btn strong {
  font-size: 15px;
  font-weight: 600;
  display: block;
}

.export-btn small {
  font-size: 12px;
  color: var(--text-secondary);
}

/* Toast */
.toast {
  position: fixed;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%);
  padding: 10px 20px;
  background: #323232;
  color: white;
  border-radius: var(--radius-sm);
  font-size: 14px;
  z-index: 200;
  animation: toastIn 0.3s ease;
  box-shadow: var(--shadow-lg);
}

@keyframes toastIn {
  from { opacity: 0; transform: translateX(-50%) translateY(20px); }
  to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* History View */
#historyView {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--surface);
  z-index: 20;
  display: flex;
  flex-direction: column;
  animation: fadeIn 0.3s ease;
}

.history-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 16px;
  border-bottom: 1px solid var(--border);
}

.history-list {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  gap: 16px;
}

.history-item {
  border-radius: var(--radius);
  overflow: hidden;
  position: relative;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: transform 0.2s;
}

.history-item:hover {
  transform: translateY(-4px);
}

.history-item img {
  width: 100%;
  height: 120px;
  object-fit: cover;
  display: block;
}

.history-meta {
  padding: 8px;
  font-size: 12px;
  text-align: center;
  background: var(--surface);
  border-top: 1px solid var(--border);
}

.history-actions {
  position: absolute;
  top: 4px;
  right: 4px;
  display: flex;
  gap: 4px;
  background: rgba(0,0,0,0.5);
  border-radius: var(--radius-full);
  padding: 2px;
}

.history-actions button {
  background: transparent;
  border: none;
  color: white;
  padding: 4px;
  cursor: pointer;
  border-radius: var(--radius-full);
}

.history-actions button:hover {
  background: rgba(255,255,255,0.2);
}

.history-actions button i {
  width: 14px;
  height: 14px;
}

@media (max-width: 768px) {
  :root {
    --sheet-width: 100vw;
  }

  .sheet-panel {
    top: auto;
    bottom: 0;
    max-width: 100vw;
    max-height: 80vh;
    border-radius: var(--radius) var(--radius) 0 0;
    animation: slideUp 0.3s ease;
  }

  @keyframes slideUp {
    from { transform: translateY(100%); }
    to { transform: translateY(0); }
  }

  #emptyState .empty-actions {
    flex-direction: column;
    width: 100%;
    max-width: 280px;
  }

  .btn {
    justify-content: center;
  }

  .logo-text {
    font-size: 16px;
  }
}

@media (min-width: 769px) {
  .filter-row {
    grid-template-columns: 1fr 1fr;
  }
}