e.background = "rgba(255, 255, 255, 0.8)"
  info.style.border = "1px solid #ccc"
  info.style.borderRadius = "3px"
  info.style.fontFamily = "'Operator Mono', 'Menlo', 'Monaco', 'Consolas', monospace"
  info.style.fontSize = "14px"
  info.innerHTML = "Hover over a polygon"
  document.getElementById('container').appendChild(info)
  
  map.once('movestart', () => {
    map.addSource("contour-source", {
      type: "vector",
      tiles: [
        demSource.contourProtocolUrl({
          thresholds: {
        