style.css

*{
	margin: 0;
	padding: 0;
	font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
	list-style: none;
	text-decoration: none;
}

.middle{
	position: absolute;
	top: 60%;
	left: 50%;
	transform: translate(-50%, -35%);
}

.menu{
	width: 400px;
	border-radius: 8px;
	overflow: hidden;
}

.item{
	border-top: 1px solid black;
	overflow: hidden;
}

.btnlist{
	text-align: center;
	font-weight: bold;
	display: block;
	padding: 16px 20px;
	background: #e0e3dc;
	color: black;
	position: relative;
}


.btnlist:before{
	content: "";
	position: absolute;
	width: 14px;
	height: 14px;
	background: #aeb0ac;
	left: 10%;
	/*bottom: -10px;*/
	transform: rotate(45deg);
}

.smenu {
	background: #c4ccba;
	overflow: hidden;
	transition: max-height 0.3s;
 	max-height: 0;
}

.smenu a{
	display:  block;
	padding: 16px 26px;
	color:  black;
	font-size:  14px;
	margin:  4px 0;
	position: relative;
}


.smenu a:before{
	content: "";
	position: absolute;
	width: 6px;
	height: 100%;
	background: black;
	left: 0;
	top: 0;
	transition: 0.3s;
	opacity : 0;
}

.smenu a:hover:before{
	opacity: 1;
}

.item:target .smenu{
	max-height: 10em;
}