style.css

body {
  cursor: default;
  padding: 0;
  border: 0;
  margin: 0;

  text-align: center;
  background-color: white;
  font-family: Helvetica, Verdana, Arial, sans-serif;
}

body, canvas, div {
  outline: none;
  -moz-user-select: none;
  -webkit-user-select: none;
  -ms-user-select: none;
  -khtml-user-select: none;
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
}

/* Remove spin of input type number */
input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
    /* display: none; <- Crashes Chrome on hover */
  -webkit-appearance: none;
  margin: 0; /* <-- Apparently some margin are still there even though it's hidden */
}

canvas {
  background-color: rgba(0, 0, 0, 0);
}

#GameDiv {
    margin: 0 auto;
    position:relative;
    border:5px solid black;
    border-radius: 10px;
    box-shadow: 0 5px 50px #333
}

#Cocos3dGameContainer, #GameCanvas {
  width: 100%;
  height: 100%;
}