body {
  margin: 0;
  padding: 0;
  overflow: hidden;
}

.whiteboard-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
}

#whiteboard {
  width: 100%;
  height: 100%;
  cursor: crosshair;
  touch-action: none;
}

.brush-preview {
  position: fixed;
  pointer-events: none;
  border: 1px solid #000;
  border-radius: 50%;
  display: none;
}

.bottom-toolbar {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  background: white;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  z-index: 1000;
  transition: transform 0.3s ease;
}

.bottom-toolbar.hidden .toolbar-content {
  display: none;
}

.bottom-toolbar.hidden .toggle-btn .material-icons {
  transform: rotate(180deg);
}

.toggle-btn {
  position: absolute;
  left: 50%;
  transform: translateX(-50%) translateY(-100%);
  border-radius: 8px 8px 0 0;
  padding: 4px 16px;
  background: white;
  border: none;
  cursor: pointer;
  box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
}

.toggle-btn .material-icons {
  transition: transform 0.3s ease;
}

.toolbar-content {
  display: flex;
  gap: 20px;
  padding: 10px;
}

.tool-group {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 10px;
  border-right: 1px solid #eee;
}

.tool-group:last-child {
  border-right: none;
}

.tool-btn {
  padding: 8px;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  background: #f5f5f5;
  display: flex;
  align-items: center;
  justify-content: center;
}

.tool-btn.active {
  background: #e0e0e0;
  color: #2196F3;
}

.tool-btn .material-icons {
  font-size: 20px;
}

#colorPicker {
  width: 40px;
  height: 40px;
  padding: 0;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

#brushSize {
  width: 100px;
}

#brushSizeLabel {
  min-width: 40px;
  text-align: center;
}

.page-controls {
  display: flex;
  align-items: center;
  gap: 10px;
}

#pageInfo {
  min-width: 80px;
  text-align: center;
}

.action-buttons {
  display: flex;
  gap: 10px;
}

.action-btn {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 8px 16px;
  border: none;
  border-radius: 4px;
  cursor: pointer;
  font-size: 14px;
  background: #f5f5f5;
  color: #333;
}

.action-btn:hover {
  background: #e0e0e0;
}

.ai-btn {
  background: #2196F3;
  color: white;
}

.ai-btn:hover {
  background: #1976D2;
}

.submit-btn {
  background: #4CAF50;
  color: white;
}

.submit-btn:hover {
  background: #388E3C;
}