* {
	box-sizing: border-box;
	padding: 0;
	margin: 0;
}
main {
	display: flex;
	flex-direction: column;
	align-items: center;
	justify-content: center;
	height: 500px;
}
.wrapper {
	position: relative;
}
button {
	position: relative;
	width: 100px;
	height: 50px;
	display: block;
}
ul {
	width: 200px;
	height: 600px;
	background: #fff;
	border-radius: 4px;
	border: 2px solid #ddd;
	list-style: none;
	padding: 4px;
}
ul li {
	width: 100%;
	display: block;
}