body{/*メッシュ(白)の背景*/
background-size:30px 30px;
background-color:#000;
background-image:
linear-gradient(90deg,transparent 25px,#fff 0),
linear-gradient(180deg,transparent 25px,#fff 0),
linear-gradient(90deg,transparent 20px,#ccc 0),
linear-gradient(180deg,transparent 20px,#ccc 0),
linear-gradient(90deg,transparent 15px,#999 0),
linear-gradient(180deg,transparent 15px,#999 0),
linear-gradient(90deg,transparent 10px,#666 0),
linear-gradient(180deg,transparent 10px,#666 0),
linear-gradient(90deg,transparent 5px,#333 0),
linear-gradient(180deg,transparent 5px,#333 0);
}