body{/*水泡の背景*/
background-size:100px 100px;
background-position:0 0,60px 75px,20px 50px,65px 30px;
background-color:#fff;
background-image:
radial-gradient(rgba(187,221,255,0.5) 35px,transparent 0),
radial-gradient(rgba(187,221,255,0.5) 30px,transparent 0),
radial-gradient(rgba(187,221,255,0.5) 25px,transparent 0),
radial-gradient(rgba(187,221,255,0.5) 20px,transparent 0);
}