html,
body {
  height: 100%;
  width: 100%;
  overflow: hidden;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  color: #e2f3ff;
}

header {
  text-align: center;
  position: absolute;
  top: 10px;
  left: 0;
  width: 100%;
  z-index: 3;
  text-shadow: 0 2px 6px rgba(15, 23, 42, 0.4);
}

main {
  position: relative;
  height: 100vh;
}

canvas {
  display: block;
  width: 100vw;
  height: 100vh;
  position: absolute;
  top: 0;
  left: 0;
  z-index: 1;
}
.legend {
  text-align: center;
  color: #e2f3ff;
  position: absolute;
  top: 60px;
  left: 50%;
  transform: translateX(-50%);
  margin: 0;
  z-index: 2;
}