<!doctype HTML>
<style>
  div {
    background: linear-gradient(rgba(0,255,0,0.5), rgba(0,0,255,0.5)), linear-gradient(rgba(0,0,0,1), rgba(0,0,0,1));
    background-size: 100px 100px, 100px 100px;
    background-position: 0 0, 0 0;
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
  }
</style>
<div></div>