html {
  margin: 0;
  height: 100%;
  overflow: hidden;
}
body {
  background: #fff;
  font-family: arial;
  font-size: 12px;
  margin: 0;
}
body.black {
  background: #000;
}
.hero {
  display: block;
  position: fixed;
  box-sizing: border-box;
  padding-top: 4px;
  text-align: center;
}

canvas {
  outline: 1px solid #000000;
}