body{/*七宝柄の背景*/
background-color:#fd9;
background-size:20px 20px;
background-position:10px 10px,0 0;
background-image:
radial-gradient(transparent 10px,rgba(255,255,255,.5) 0),
radial-gradient(transparent 10px,rgba(255,255,255,.7) 0);
}