body{/*ソファー柄の背景(黒)*/
background-size:100px 100px;
background-position:50px 50px,0 0,0 0,0 0;
background-color:#222;
background-image:
radial-gradient(#666 1px,#444 3px,#222 8px,#000 8px,rgba(17,17,17,0) 13px),
radial-gradient(#666 1px,#444 3px,#222 8px,#000 8px,rgba(17,17,17,0) 13px),
linear-gradient(45deg,rgba(0,0,0,0.5),rgba(17,17,17,0) 10%,rgba(17,17,17,0) 40%,rgba(255,255,255,0.1) 50%,rgba(0,0,0,0.5) 50%,rgba(17,17,17,0) 60%,rgba(17,17,17,0) 90%,rgba(255,255,255,0.1)),
linear-gradient(-45deg,rgba(0,0,0,0.5),rgba(17,17,17,0) 10%,rgba(17,17,17,0) 40%,rgba(255,255,255,0.1) 50%,rgba(0,0,0,0.5) 50%,rgba(17,17,17,0) 60%,rgba(17,17,17,0) 90%,rgba(255,255,255,0.1));
}