@charset "utf-8";
body::before{
 content: "";
 display: block;
 position: fixed;
 top: 0;
 left: 0;
 width: 100vw;
 height: 100vh;
 z-index: -1;
 background-repeat : no-repeat;
 background-image : url(../img_common/back2.jpg);
 background-position : center top;
 background-attachment : fixed;
 background-size:cover;
}