body {
  margin: 0;
  overflow: hidden;
  background: #f0f0f0;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

#sidebar {
  position: absolute;
  top: 0;
  left: 0;
  width: 260px;
  height: 100vh;
  background: rgba(255, 255, 255, 0.98);
  border-right: 1px solid #ccc;
  padding: 12px 14px;
  box-sizing: border-box;
  z-index: 100;
  font-size: 14px;
}

#sidebar h1 {
  margin: 0 0 10px 0;
  font-size: 18px;
}

.section {
  margin-bottom: 12px;
}

.section.small {
  font-size: 12px;
}

#modeSelect {
  width: 100%;
  padding: 4px;
  margin-top: 4px;
  font-size: 14px;
}

button {
  padding: 4px 10px;
  font-size: 13px;
  border-radius: 4px;
  border: 1px solid #888;
  background: #f5f5f5;
  cursor: pointer;
}

button:hover {
  background: #e8e8e8;
}

#canvas {
  position: absolute;
  left: 260px;
  top: 0;
  right: 0;
  bottom: 0;
  display: block;
  background-color: white;
}