.container{
	overflow: hidden;
}
.container div{height:300px;}

.slidein{
	/* 装飾に関わるスタイルは省略 */
	margin: 50px auto;
	transition: 1s cubic-bezier(0.75, 0, 0.25, 1);
}
.slide_left{
	transform: translateX(calc(-50vw - 50%));
}
.slide_right{
	transform: translateX(calc(50vw + 50%));
}
.show{
	transform: translateX(0);
}