Vertical and Horizontal center

<style type="text/css">
body, html{height: 100%; margin: 0px; pading: 0px}
.class1st{display: table; height: 100%; #position: relative; overflow: hidden; width: 100%}
.class2nd{#position: absolute; #top: 50%;display: table-cell; vertical-align: middle; width: 100%}
.class3rd{#position: relative; #top: -50%; text-align: center; width: 100%}
</style>
<div class="class1st">
<div class="class2nd">
<div class="class3rd">
    <img src="logo.png">
</div>
</div>
</div>
</body>