.box {
	display:flex;
	position:relative;
	height:100px;
	margin-left:100px;
	position:relative;
}
.round {
	width:50px;
	height:50px;
	border-radius:50%;
	display:flex;
	align-items:center;
	justify-content:center;
	position:absolute;
	top:0;
	opacity:0;
}
.color1 {
	background-color:#f00;
}
.color2 {
	background-color:#f0f;
}
.color3 {
	background-color:#ff0;
}
.color4 {
	background-color:#00f;
}
.color5 {
	background-color:#0f0;
}
.color6 {
	background-color:#0ff;
}
.round:nth-child(1) {
	transition:all 1s ease-in-out;
	left:0;
	opacity:0;
	z-index:5;
}
.round:nth-child(2) {
	transition:all 0.8s ease-in-out;
	left:100px;
	opacity:1;
	z-index:4;
}
.round:nth-child(3) {
	transition:all 0.8s ease-in-out;
	left:120px;
	opacity:1;
	z-index:3;
}
.round:nth-child(4) {
	transition:all 0.8s ease-in-out;
	left:140px;
	opacity:1;
	z-index:2;
}
.round:nth-child(5) {
	transition:all 0.8s ease-in-out;
	left:160px;
	opacity:1;
	z-index:1;
}
.round:nth-child(n+6) {
	transition:all 0.8s ease-in-out;
	opacity:0;
	z-index:0;
}
.btn {
	background-color:#f00;
	color:#fff;
	padding:20px;
	margin-bottom:10px;
	cursor:pointer;
}