index.css

* {

  margin: 0px;
  padding: 0px;

  text-align: center;
  font-family: Arial, Helvetica, sans-serif;

  box-sizing: border-box;

}

#canvas {

  top: 0px;
  left: 0px;

  width: 100%;
  height: 100%;

  z-index: 1;
  position: fixed;

  pointer-events: none;

}

#forkme {

  top: 0px;
  right: 0px;

  width: 150px;
  height: 150px;

  position: fixed;

  z-index: calc(9e999);

  clip-path: polygon(15px 0px, 60px 0px, 150px 90px, 150px 135px);

}

#title {

  margin: auto;
  padding: 50px;

}

#start {

  top: 40%;
  left: 50%;

  width: 200px;
  padding: 25px;

  color: white;
  background-color: green;

  border-radius: 10px;
  border: 2px solid black;

  transform: translate(-50%, -50%);
  position: absolute;

  cursor: pointer;

}

#start:hover {

  color: black;
  background-color: lightgreen;

}