.introBtn{width:100%; text-align:center; position:absolute; z-index:10;}
.introBtn a{}

.mainBottom{height:300px; background-color:white; width:100%; position:relative;left:0; z-index:10;}
.subBottom{height:300px; background-color:white; width:100%; }



/* layout */
html,body{height:100%; }
#bg{width:100%; height:100%; position:relative;}
#bg .opacity{display:none; width:100%; height:100%; z-index:2; position:fixed; left:0; bottom:0; top:0; background:url('/image/opacity_bg.png') repeat;}
#bg ul li{width:100%; height:100%; display:none; overflow:hidden; background-position:center top; background-repeat:no-repeat; background-size:cover; position:absolute; left:0; top:0;}
#bg ul li:first-child{display:block;}
#bg ul li img{position:fixed; left:-1000%; top:0}
#wrap{position:relative; z-index:3;}
#navigation{position:absolute; left:55px; top:60px; z-index:10;}
#address_main{position:absolute; left:55px; bottom:45px; z-index:10;}
#logo_main{position:absolute; right:51px; top:34px; z-index:10;}