<!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>