* {
  margin: 0;
  padding: 0;
  border: 0;
  overflow: hidden;
}

body {
  background: #000;
  font: 30px sans-serif;
}

#container {
    position: absolute;
    top: 0px;
    width:100%;
    height:100%;
    z-index: -1;
}

#rendercontainer {
    position: absolute;
    top: 0px;
    width:100%;
    height:100%;
    z-index: -1;
    background-color:Red;
}