.main_bg{
	position: absolute;
	z-index: -1;
	left: 0;
	top: 0;
	width: 100%;
	height: 100%;
}
.main_bg .bx-wrapper,
.main_bg .bx-viewport,
.main_bg_slide{
	height: 100% !important;
	border: 0px;
	box-shadow: none;
}
.main_bg_01{
	background: url(../images/kv/main_bg_01_large.jpg);
	background-size: cover;
	background-position: center;
	width: 100%;
	height: 100%;
}
.main_bg_02{
	background: url(../images/kv/main_bg_02_large.jpg);
	background-size: cover;
	background-position: center;
	width: 100%;
	height: 100%;
}
.main_bg_03{
	background: url(../images/kv/main_bg_03_large.jpg);
	background-size: cover;
	background-position: center;
	width: 100%;
	height: 100%;
}
.main_bg_04{
	background: url(../images/kv/main_bg_04_large.jpg);
	background-size: cover;
	background-position: center;
	width: 100%;
	height: 100%;
}

@media screen and (max-width: 640px) {
  .main_bg_01{
    background: url(../images/kv/main_bg_01_small.jpg);
		background-size: cover;
		background-position: center;
  }
  .main_bg_02{
    background: url(../images/kv/main_bg_02_small.jpg);
		background-size: cover;
		background-position: center;
  }
  .main_bg_03{
    background: url(../images/kv/main_bg_03_small.jpg);
		background-size: cover;
		background-position: center;
  }
  .main_bg_04{
    background: url(../images/kv/main_bg_04_small.jpg);
		background-size: cover;
		background-position: center;
  }
}