<div class="c-dropdown">
	<div class="c-dropdown__label">Dropdown</div>
	<ul class="c-dropdown__panel">
		<li>a</li>
		<li>b</li>
		<li>c</li>
		<li>d</li>
		<li>e</li>
	</ul>
</div>

.c-dropdown {
	cursor: pointer;
	transition: .3s all ease-in-out;
	
	&__label {
		border: 1px solid grey;	
		padding: .5rem;
		border-radius: 3px;
	}
	
	&__panel {
		padding: .5rem;
		margin: .1rem 0;
		list-style-type: none;
		border: 1px solid grey;
		visibility: hidden;
		border-radius: 3px;
	}
	
	&:focus,
	&:hover {
		.c-dropdown__panel {
			visibility: visible;
		}
	}
}