html, body {
  margin: 0;
  padding: 0;
  overflow: hidden;
  font-family: monospace;
  background: black;
  color: white;
  height: 100%;
}

#gameCanvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  display: block;
  z-index: 0;
}

#legend {
  position: absolute;
  bottom: 20px;
  right: 20px;
  z-index: 2;
  background-color: rgba(255, 255, 255, 0.1);
  color: #ccc;
  padding: 8px 12px;
  font-size: 14px;
  border: 1px dashed #888;
  border-radius: 4px;
  line-height: 1.4;
}