body{/*鹿の子模様*/
background-size:40px 40px;
background-position:20px 20px,0 0;
background-image:
radial-gradient(transparent 5px,#fff 5px,#fff 10px,transparent 10px),
radial-gradient(c33 5px,#fff 5px,#fff 10px,c33 10px);
}