body {
background:
radial-gradient(#000 15%, transparent 16%) 0 0,
radial-gradient(#000 15%, transparent 16%) 8px 8px,
radial-gradient(rgba(255,255,255,.1) 15%, transparent 20%) 0 1px,
radial-gradient(rgba(255,255,255,.1) 15%, transparent 20%) 8px 9px;
background-color:#282828;
background-size:16px 16px;
}