#map_canvas {
  height: 600px;
  width: 100%;
}

div.overlay {
  display: none;
  z-index: 1;
  padding: 5px;
  bottom: 0;
  left: 0;
  position: absolute;
}

div.overlay div {
  padding: 5px;
  background-color: #fff;
}

div.overlay label:not(:last-child) {
  margin-right: 5px;
}