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

:root {
  --bg: #f0f2f5;
  --surface: #ffffff;
  --surface-hover: #f5f7fa;
  --border: #d1d5db;
  --text: #1f2937;
  --text-secondary: #6b7280;
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --danger: #ef4444;
  --danger-hover: #dc2626;
  --shadow: 0 1px 3px rgba(0,0,0,0.1);
  --shadow-lg: 0 4px 12px rgba(0,0,0,0.15);
  --radius: 8px;
  --sidebar-w: 280px;
  --toolbar-h: 56px;
  --status-h: 32px;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

html, body {
  height: 100%;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  overflow: hidden;
  font-size: 13px;
  line-height: 1.5;
}

#app {
  display: flex;
  height: 100vh;
}

#sidebar {
  width: var(--sidebar-w);
  min-width: var(--sidebar-w);
  background: var(--surface);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.sidebar-header {
  padding: 16px;
  border-bottom: 1px solid var(--border);
}

.sidebar-header h1 {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
}

.sidebar-header .subtitle {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 2px;
}

.upload-area {
  padding: 12px;
}

.upload-placeholder {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  color: var(--text-secondary);
}

.upload-placeholder:hover {
  border-color: var(--primary);
  background: var(--surface-hover);
  color: var(--primary);
}

.upload-placeholder svg {
  margin-bottom: 8px;
}

.upload-placeholder p {
  font-weight: 600;
  font-size: 14px;
}

.upload-placeholder span {
  font-size: 11px;
}

.upload-area.dragover .upload-placeholder {
  border-color: var(--primary);
  background: #eff6ff;
  color: var(--primary);
}

.upload-options {
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: 8px;
  font-size: 11px;
  color: var(--text-secondary);
}

.copy-count-input {
  width: 56px;
  padding: 3px 6px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 12px;
  text-align: center;
  font-family: inherit;
  color: var(--text);
}

.photo-thumb-dup {
  width: 20px;
  height: 20px;
  border: none;
  background: none;
  cursor: pointer;
  color: var(--text-secondary);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
}

.photo-thumb-dup:hover {
  color: var(--primary);
  background: #eff6ff;
}

.photo-list {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border-top: 1px solid var(--border);
}

.list-header {
  display: flex;
  justify-content: space-between;
  padding: 10px 16px;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border);
}

.photo-count {
  background: var(--bg);
  padding: 0 8px;
  border-radius: 10px;
  font-size: 11px;
}

.list-items {
  flex: 1;
  overflow-y: auto;
  padding: 4px;
}

.photo-thumb {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s;
}

.photo-thumb:hover {
  background: var(--surface-hover);
}

.photo-thumb.active {
  background: #eff6ff;
  outline: 1px solid var(--primary);
}

.photo-thumb img {
  width: 44px;
  height: 44px;
  object-fit: cover;
  border-radius: 4px;
  background: var(--bg);
}

.photo-thumb-info {
  flex: 1;
  min-width: 0;
}

.photo-thumb-name {
  font-size: 12px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.photo-thumb-size {
  font-size: 11px;
  color: var(--text-secondary);
}

.photo-thumb-del {
  width: 20px;
  height: 20px;
  border: none;
  background: none;
  cursor: pointer;
  color: var(--text-secondary);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
}

.photo-thumb-del:hover {
  color: var(--danger);
  background: #fef2f2;
}

#main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.toolbar {
  height: var(--toolbar-h);
  min-height: var(--toolbar-h);
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 16px;
  overflow-x: auto;
}

.toolbar-group {
  display: flex;
  align-items: center;
  gap: 4px;
  white-space: nowrap;
}

.toolbar-group label {
  font-size: 12px;
  color: var(--text-secondary);
  font-weight: 500;
}

.toolbar-group select,
.toolbar-group input {
  font-size: 12px;
  padding: 4px 8px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--surface);
  color: var(--text);
  font-family: inherit;
}

.toolbar-group select:focus,
.toolbar-group input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(37,99,235,0.15);
}

.toolbar-actions {
  display: flex;
  gap: 6px;
  margin-left: auto;
}

.btn {
  font-size: 12px;
  font-weight: 600;
  padding: 6px 14px;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: all 0.15s;
  font-family: inherit;
  white-space: nowrap;
}

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

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

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

.btn-secondary:hover {
  background: var(--surface-hover);
  border-color: #9ca3af;
}

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

.btn-danger:hover {
  background: #fef2f2;
}

.canvas-container {
  flex: 1;
  background: var(--bg);
  position: relative;
  overflow: auto;
  display: flex;
  align-items: center;
  justify-content: center;
}

.canvas-area {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px;
  min-width: 100%;
  min-height: 100%;
}

.paper-canvas {
  position: relative;
  background: white;
  box-shadow: var(--shadow-lg);
  transform-origin: center center;
  overflow: hidden;
}

.photo-item {
  position: absolute;
  cursor: move;
  overflow: hidden;
  border: 2px solid transparent;
  transition: border-color 0.15s;
  user-select: none;
}

.photo-item:hover {
  border-color: rgba(37,99,235,0.3);
}

.photo-item.selected {
  border-color: var(--primary);
  box-shadow: 0 0 0 1px var(--primary);
}

.photo-item img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  pointer-events: none;
}

.resize-handle {
  position: absolute;
  right: -4px;
  bottom: -4px;
  width: 12px;
  height: 12px;
  background: var(--primary);
  border: 2px solid white;
  border-radius: 50%;
  cursor: nwse-resize;
  z-index: 10;
  opacity: 0;
  transition: opacity 0.15s;
}

.photo-item:hover .resize-handle,
.photo-item.selected .resize-handle {
  opacity: 1;
}

.photo-delete-btn {
  position: absolute;
  top: -10px;
  right: -10px;
  width: 22px;
  height: 22px;
  border: none;
  background: var(--danger);
  color: white;
  border-radius: 50%;
  cursor: pointer;
  font-size: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.15s;
  z-index: 10;
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}

.photo-item:hover .photo-delete-btn,
.photo-item.selected .photo-delete-btn {
  opacity: 1;
}

.canvas-empty {
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  gap: 8px;
}

.canvas-empty.show {
  display: flex;
}

.status-bar {
  height: var(--status-h);
  min-height: var(--status-h);
  background: var(--surface);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  font-size: 12px;
  color: var(--text-secondary);
}

#coverageText {
  font-weight: 600;
}

.context-menu {
  display: none;
  position: fixed;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  box-shadow: var(--shadow-lg);
  z-index: 1000;
  min-width: 140px;
  padding: 4px;
}

.context-menu .menu-item {
  padding: 8px 12px;
  cursor: pointer;
  border-radius: 4px;
  font-size: 13px;
}

.context-menu .menu-item:hover {
  background: var(--surface-hover);
}

.photo-tooltip {
  position: fixed;
  background: #1f2937;
  color: white;
  padding: 6px 10px;
  border-radius: 6px;
  font-size: 12px;
  line-height: 1.4;
  pointer-events: none;
  z-index: 9999;
  box-shadow: 0 2px 8px rgba(0,0,0,0.3);
  white-space: nowrap;
}

.photo-tooltip strong {
  font-weight: 600;
}

.photo-item .cover-img {
  object-fit: cover;
}

.photo-item .contain-img {
  object-fit: contain;
}

@media (max-width: 768px) {
  #app {
    flex-direction: column;
  }
  #sidebar {
    width: 100%;
    min-width: unset;
    max-height: 40vh;
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .toolbar {
    flex-wrap: wrap;
    height: auto;
    padding: 8px 12px;
    gap: 8px;
  }
  .toolbar-actions {
    margin-left: 0;
  }
}

@media print {
  body {
    background: white;
  }
  #sidebar, .toolbar, .status-bar {
    display: none !important;
  }
  .canvas-container {
    overflow: visible;
    display: block;
  }
  .canvas-area {
    padding: 0;
    min-height: auto;
  }
  .paper-canvas {
    box-shadow: none;
  }
  .photo-delete-btn, .resize-handle {
    display: none !important;
  }
  .photo-item {
    border-color: transparent !important;
    box-shadow: none !important;
  }
  #main {
    overflow: visible;
  }
}