<head>
<style>
body {margin: 0; padding: 0;}
html, body {height: 100%; padding: 0; margin: 0;}
div {width: 50%; height: 50%; float: left;}
#solust img {position: relative; top: 50%; left: 50%; transform: translate(-50%, -50%);}
#sagust img {position: relative; top: 50%; left: 50%; transform: translate(-50%, -50%);}
#solalt img {position: relative; top: 50%; left: 50%; transform: translate(-50%, -50%);}
#sagalt img {position: relative; top: 50%; left: 50%; transform: translate(-50%, -50%);}
#solust {background: #777;}
#sagust {background: #333;}
#solalt {background: #333;}
#sagalt {background: #777;}
</style>
</head>
<body>
<div id="solust">
<a href="#"><img src="https://cdn.r10.net/modern/img/logo/svg/light.svg"></a>
</div>
<div id="sagust">
<a href="#"><img src="https://cdn.r10.net/modern/img/logo/svg/light.svg"></a>
</div>
<div id="solalt">
<a href="#"><img src="https://cdn.r10.net/modern/img/logo/svg/light.svg"></a>
</div>
<div id="sagalt">
<a href="#"><img src="https://cdn.r10.net/modern/img/logo/svg/light.svg"></a>
</div>
</body>