Vertically Center the Logo img

Fixed parent, how to vertically center an img

HTML

<div id="container">

	<div id="logocontainer">	
	
		<a href="/"> <img src="images/logo.svg" alt="Logo." /> </a>
	
	</div>		
	
</div>

CSS

#container {
	background-color: black;
	z-index: 0;
	position: fixed;
	left: 0;
	right: 0;
	top: 0;
	bottom: 0;
	width: 100%;
	height: 100%;
}

#logocontainer {
  position: fixed;
	margin: 0 auto;
	z-index: 1;
	left: 0;
	right: 0;
	top: 0;
	bottom: 0;
	width: 50%;
	height: 100%;
  display: inline-block;
	vertical-align: middle;
  align-items: center;
  justify-content: center;
  text-align: center;
}

#logocontainer img {
	width: 100%;
}