@charset "UTF-8";
/* CSS Document */

*,*::before,*::after{
	box-sizing: border-box;
}

body{
	color:#333;
}

a{
	color:#333;
	text-decoration: none;
}

header{
	background-color: #333;
	color:#fff;
	height: 80vh;
	display: flex;
	align-items: center;
	justify-content: center;
	font-size:50px;
}

main{
	max-width:1000px;
	width:100%;
	margin: 50px auto;
	background-color: #eee;
}

.button{
	width:200px;
	height: 40px;
	margin-top: 100px;
}

.button > a{
	 width:100%;
	height: 100%;
	display: flex;
	align-items: center;
	justify-content: center;
	border-radius: 5px;
	border:1px solid #555;
	background-color: #fff;
}

.picture{
	width:700px;
	height: 200px;
	margin-top: 100px;
}

.picture > div{
	height: 100%;
	background-image: url("../images/kouyou.jpg");
	background-size:cover;
	background-repeat: no-repeat;
	background-position: center;
}


.picture:nth-of-type(2n){
	margin-left: auto;
}

.animation_target{
	position: relative;
	overflow: hidden;
}

.animation_target > a,
.animation_target > div{
	opacity: 0;
}

@keyframes showEl{
	0%{
		opacity: 0;
	}
	100%{
		opacity: 1;
	}
}

.animation_target.show > a,
.animation_target.show > div{
	animation: showEl .01s .9s forwards;
}

.animation_target::before{
	content: "";
	display: block;
	position: absolute;
	top: 0;
	left: 0;
	z-index: 1;
	width: 100%;
	height: 100%;
	background-color: #333;
	transform: translateX(-100%);
}

@keyframes showmask{
	0%{
		transform: translateX(-100%);
	}
	45%,55%{
		transform: translateX(0%);
	}
	100%{
		transform: translateX(100%);
	}
}

.animation_target.show::before{
	animation: showmask 1.8s forwards;
}