body{/*青海波もどき(5本・色反転)の背景*/
background-size:40px 40px;
background-position:0 20px,20px 20px,20px 0,0 0,0 0;
background-image:
linear-gradient(45deg,#7dd 2%,#fff 2%,#fff 5%,#7dd 5%,#7dd 12%,#fff 12%,#fff 15%,#7dd 15%,#7dd 22%,#fff 22%,#fff 25%,transparent 25%),
linear-gradient(-45deg,#7dd 7%,#fff 7%,#fff 10%,#7dd 10%,#7dd 17%,#fff 17%,#fff 20%,#7dd 20%,#7dd 27%,#fff 27%,#fff 30%,#7dd 30%,#7dd 37%,#fff 37%,#fff 40%,#7dd 40%,#7dd 47%,#fff 47%,#fff 50%,transparent 50%),
linear-gradient(45deg,#7dd 2%,#fff 2%,#fff 5%,#7dd 5%,#7dd 12%,#fff 12%,#fff 15%,#7dd 15%,#7dd 22%,#fff 22%,#fff 25%,transparent 25%),
linear-gradient(-45deg,#7dd 7%,#fff 7%,#fff 10%,#7dd 10%,#7dd 17%,#fff 17%,#fff 20%,#7dd 20%,#7dd 27%,#fff 27%,#fff 30%,#7dd 30%,#7dd 37%,#fff 37%,#fff 40%,#7dd 40%,#7dd 47%,#fff 47%,#fff 50%,transparent 50%),
linear-gradient(45deg,#7dd 7%,#fff 7%,#fff 10%,#7dd 10%,#7dd 17%,#fff 17%,#fff 20%,#7dd 20%,#7dd 27%,#fff 27%,#fff 30%,#7dd 30%,#7dd 37%,#fff 37%,#fff 40%,#7dd 40%,#7dd 47%,#fff 47%,#fff 50%,#7dd 50%,#7dd 57%,#fff 57%,#fff 60%,#7dd 60%,#7dd 67%,#fff 67%,#fff 70%,#7dd 70%,#7dd 77%,#fff 77%,#fff 80%,#7dd 80%,#7dd 87%,#fff 87%,#fff 90%,#7dd 90%,#7dd 97%,#fff 97%);
}

body{/*青海波もどき(5本・色反転)(逆さま)の背景*/
background-size:40px 40px;
background-position:0 20px,20px 20px,20px 0,0 0,0 0;
background-image:
linear-gradient(-135deg,#7dd 2%,#fff 2%,#fff 5%,#7dd 5%,#7dd 12%,#fff 12%,#fff 15%,#7dd 15%,#7dd 22%,#fff 22%,#fff 25%,transparent 25%),
linear-gradient(135deg,#7dd 7%,#fff 7%,#fff 10%,#7dd 10%,#7dd 17%,#fff 17%,#fff 20%,#7dd 20%,#7dd 27%,#fff 27%,#fff 30%,#7dd 30%,#7dd 37%,#fff 37%,#fff 40%,#7dd 40%,#7dd 47%,#fff 47%,#fff 50%,transparent 50%),
linear-gradient(-135deg,#7dd 2%,#fff 2%,#fff 5%,#7dd 5%,#7dd 12%,#fff 12%,#fff 15%,#7dd 15%,#7dd 22%,#fff 22%,#fff 25%,transparent 25%),
linear-gradient(135deg,#7dd 7%,#fff 7%,#fff 10%,#7dd 10%,#7dd 17%,#fff 17%,#fff 20%,#7dd 20%,#7dd 27%,#fff 27%,#fff 30%,#7dd 30%,#7dd 37%,#fff 37%,#fff 40%,#7dd 40%,#7dd 47%,#fff 47%,#fff 50%,transparent 50%),
linear-gradient(-135deg,#7dd 7%,#fff 7%,#fff 10%,#7dd 10%,#7dd 17%,#fff 17%,#fff 20%,#7dd 20%,#7dd 27%,#fff 27%,#fff 30%,#7dd 30%,#7dd 37%,#fff 37%,#fff 40%,#7dd 40%,#7dd 47%,#fff 47%,#fff 50%,#7dd 50%,#7dd 57%,#fff 57%,#fff 60%,#7dd 60%,#7dd 67%,#fff 67%,#fff 70%,#7dd 70%,#7dd 77%,#fff 77%,#fff 80%,#7dd 80%,#7dd 87%,#fff 87%,#fff 90%,#7dd 90%,#7dd 97%,#fff 97%);
}