body {
  margin: 0;
  overflow: hidden;
  font-family: sans-serif;
}

#mainMenu {
  position: absolute;
  top: 10px;
  right: 10px;
  background: rgba(0,0,0,0.6);
  color: #fff;
  padding: 8px 12px;
  border-radius: 4px;
  z-index: 10;
}

#mainMenu button {
  background: #444;
  color: #fff;
  border: none;
  padding: 6px 10px;
  margin: 0;
  cursor: pointer;
  border-radius: 3px;
}

#tutorial {
  position: absolute;
  left: 10px;
  bottom: 10px;
  background: rgba(0,0,0,0.6);
  color: #fff;
  padding: 6px 10px;
  border-radius: 4px;
  font-size: 14px;
  line-height: 1.4em;
}